(l10n): Add Korean translation (#301)

build(deps): bump github.com/valyala/fasthttp from 1.54.0 to 1.55.0 in the gomod group

.devcontainer/devcontainer.json

@@ -0,0 +1,18 @@
+{
+  "$schema": "https://raw.githubusercontent.com/devcontainers/spec/main/schemas/devContainer.base.schema.json",
+  "name": "default",
+  "image": "golang:1.22-bookworm",
+  "features": {
+    "ghcr.io/guiyomh/features/golangci-lint:0": {},
+    "ghcr.io/devcontainers/features/github-cli:1": {},
+    "ghcr.io/devcontainers/features/sshd:1": {}
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "streetsidesoftware.code-spell-checker"
+      ]
+    }
+  },
+  "postCreateCommand": "go mod download"
+}

.github/workflows/release.yml

@@ -36,7 +36,7 @@ jobs:
           tag: ${{ github.ref }}
 
       - if: matrix.os == 'linux' && matrix.arch == 'amd64'
-        run: mkdir ./out && ./${{ steps.values.outputs.binary-name }} build --index --target-dir ./out
+        run: mkdir ./out && ./${{ steps.values.outputs.binary-name }} build --index --disable-minification --target-dir ./out
       - if: matrix.os == 'linux' && matrix.arch == 'amd64'
         uses: actions/upload-artifact@v4
         with:
@@ -44,6 +44,16 @@ jobs:
           path: out/
           if-no-files-found: error
           retention-days: 1
+      - if: matrix.os == 'linux' && matrix.arch == 'amd64'
+        working-directory: ./out
+        run: zip -r ./../templates.zip .
+      - if: matrix.os == 'linux' && matrix.arch == 'amd64'
+        uses: svenstaro/upload-release-action@v2
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          file: templates.zip
+          asset_name: error-pages-static.zip
+          tag: ${{ github.ref }}
 
   demo:
     name: Update the demo (GitHub Pages)
@@ -76,20 +86,19 @@ jobs:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      - uses: docker/build-push-action@v5
+      - uses: docker/build-push-action@v6
         with:
           context: .
           file: Dockerfile
           push: true
           platforms: linux/amd64,linux/arm/v7,linux/arm64/v8
           build-args: "APP_VERSION=${{ steps.slug.outputs.version }}"
-          tags: ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version }}
-#         tags: | # TODO: uncomment after the stable release
-#           tarampampam/error-pages:latest
-#           tarampampam/error-pages:${{ steps.slug.outputs.version }}
-#           tarampampam/error-pages:${{ steps.slug.outputs.version-major }}.${{ steps.slug.outputs.version-minor }}
-#           tarampampam/error-pages:${{ steps.slug.outputs.version-major }}
-#           ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:latest
-#           ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version }}
-#           ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version-major }}.${{ steps.slug.outputs.version-minor }}
-#           ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version-major }}
+          tags: |
+            tarampampam/error-pages:latest
+            tarampampam/error-pages:${{ steps.slug.outputs.version }}
+            tarampampam/error-pages:${{ steps.slug.outputs.version-major }}.${{ steps.slug.outputs.version-minor }}
+            tarampampam/error-pages:${{ steps.slug.outputs.version-major }}
+            ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:latest
+            ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version }}
+            ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version-major }}.${{ steps.slug.outputs.version-minor }}
+            ghcr.io/${{ github.actor }}/${{ github.event.repository.name }}:${{ steps.slug.outputs.version-major }}

.github/workflows/tests.yml

@@ -83,7 +83,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - {uses: gacts/github-slug@v1, id: slug}
-      - uses: docker/build-push-action@v5
+      - uses: docker/build-push-action@v6
         with:
           context: .
           file: Dockerfile

Dockerfile

@@ -3,7 +3,7 @@
 # -✂- this stage is used to develop and build the application locally -------------------------------------------------
 FROM docker.io/library/golang:1.22-bookworm AS develop
 
-# use the /var/tmp as the GOPATH to reuse the modules cache
+# use the /var/tmp/go as the GOPATH to reuse the modules cache
 ENV GOPATH="/var/tmp/go"
 
 RUN set -x \
@@ -32,7 +32,10 @@ FROM develop AS compile
 # can be passed with any prefix (like `v1.2.3@GITHASH`), e.g.: `docker build --build-arg "APP_VERSION=v1.2.3" .`
 ARG APP_VERSION="undefined@docker"
 
-RUN --mount=type=bind,source=.,target=/src set -x \
+# copy the source code
+COPY . /src
+
+RUN set -x \
     && go generate ./... \
     && CGO_ENABLED=0 LDFLAGS="-s -w -X gh.tarampamp.am/error-pages/internal/appmeta.version=${APP_VERSION}" \
       go build -trimpath -ldflags "${LDFLAGS}" -o /tmp/error-pages ./cmd/error-pages/ \
@@ -45,10 +48,11 @@ FROM docker.io/library/alpine:3.20 AS rootfs
 WORKDIR /tmp/rootfs
 
 # prepare rootfs for runtime
-RUN --mount=type=bind,source=.,target=/src set -x \
-    && mkdir -p ./etc ./bin \
+RUN set -x \
+    && mkdir -p ./etc/ssl/certs ./bin \
     && echo 'appuser:x:10001:10001::/nonexistent:/sbin/nologin' > ./etc/passwd \
-    && echo 'appuser:x:10001:' > ./etc/group
+    && echo 'appuser:x:10001:' > ./etc/group \
+    && cp /etc/ssl/certs/ca-certificates.crt ./etc/ssl/certs/
 
 # take the binary from the compile stage
 COPY --from=compile /tmp/error-pages ./bin/error-pages
@@ -69,7 +73,7 @@ ARG APP_VERSION="undefined@docker"
 LABEL \
     # docs: https://github.com/opencontainers/image-spec/blob/master/annotations.md
     org.opencontainers.image.title="error-pages" \
-    org.opencontainers.image.description="Static server error pages in the docker image" \
+    org.opencontainers.image.description="Pretty server's error pages" \
     org.opencontainers.image.url="https://github.com/tarampampam/error-pages" \
     org.opencontainers.image.source="https://github.com/tarampampam/error-pages" \
     org.opencontainers.image.vendor="tarampampam" \
@@ -87,11 +91,12 @@ WORKDIR /opt
 # to find out which environment variables and CLI arguments are supported by the application, run the app
 # with the `--help` flag or refer to the documentation at https://github.com/tarampampam/error-pages#readme
 
+ENV LOG_LEVEL="warn" \
+    LOG_FORMAT="json"
+
 # docs: https://docs.docker.com/reference/dockerfile/#healthcheck
-HEALTHCHECK --interval=10s --start-interval=1s --start-period=5s --timeout=2s CMD [\
-  "/bin/error-pages", "--log-format", "json", "healthcheck" \
-]
+HEALTHCHECK --interval=10s --start-interval=1s --start-period=5s --timeout=2s CMD ["/bin/error-pages", "healthcheck"]
 
 ENTRYPOINT ["/bin/error-pages"]
 
-CMD ["--log-format", "json", "serve"]
+CMD ["serve"]

go.mod

@@ -4,8 +4,10 @@ go 1.22
 
 require (
 	github.com/stretchr/testify v1.9.0
+	github.com/tdewolff/minify/v2 v2.20.35
 	github.com/urfave/cli-docs/v3 v3.0.0-alpha5
 	github.com/urfave/cli/v3 v3.0.0-alpha9
+	github.com/valyala/fasthttp v1.55.0
 	go.uber.org/automaxprocs v1.5.3
 )
 
@@ -18,8 +20,8 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rogpeppe/go-internal v1.12.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/tdewolff/parse/v2 v2.7.15 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
-	github.com/valyala/fasthttp v1.55.0 // indirect
 	github.com/xrash/smetrics v0.0.0-20240521201337-686a1a2994c1 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -26,6 +26,13 @@ github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/tdewolff/minify/v2 v2.20.35 h1:/Vq/oivpkFyi2PViD25XHZZbJz+eO4OmPSgePex1kBU=
+github.com/tdewolff/minify/v2 v2.20.35/go.mod h1:L1VYef/jwKw6Wwyk5A+T0mBjjn3mMPgmjjA688RNsxU=
+github.com/tdewolff/parse/v2 v2.7.15 h1:hysDXtdGZIRF5UZXwpfn3ZWRbm+ru4l53/ajBRGpCTw=
+github.com/tdewolff/parse/v2 v2.7.15/go.mod h1:3FbJWZp3XT9OWVN3Hmfp0p/a08v4h8J9W1aghka0soA=
+github.com/tdewolff/test v1.0.11-0.20231101010635-f1265d231d52/go.mod h1:6DAvZliBAAnD7rhVgwaM7DE5/d9NMOAJ09SqYqeK4QE=
+github.com/tdewolff/test v1.0.11-0.20240106005702-7de5f7df4739 h1:IkjBCtQOOjIn03u/dMQK9g+Iw9ewps4mCl1nB8Sscbo=
+github.com/tdewolff/test v1.0.11-0.20240106005702-7de5f7df4739/go.mod h1:XPuWBzvdUzhCuxWO1ojpXsyzsA5bFoS3tO/Q3kFuTG8=
 github.com/urfave/cli-docs/v3 v3.0.0-alpha5 h1:H1oWnR2/GN0dNm2PVylws+GxSOD6YOwW/jI5l78YfPk=
 github.com/urfave/cli-docs/v3 v3.0.0-alpha5/go.mod h1:AIqom6Q60U4tiqHp41i7+/AB2XHgi1WvQ7jOFlccmZ4=
 github.com/urfave/cli/v3 v3.0.0-alpha9 h1:P0RMy5fQm1AslQS+XCmy9UknDXctOmG/q/FZkUFnJSo=

internal/cli/app.go

@@ -6,7 +6,6 @@ import (
 	"runtime"
 	"strings"
 
-	_ "github.com/urfave/cli-docs/v3" // required for `go generate` to work
 	"github.com/urfave/cli/v3"
 
 	"gh.tarampamp.am/error-pages/internal/appmeta"
@@ -17,7 +16,7 @@ import (
 	"gh.tarampamp.am/error-pages/internal/logger"
 )
 
-//go:generate go run update_readme.go
+//go:generate go run app_generate.go
 
 // NewApp creates a new console application.
 func NewApp(appName string) *cli.Command { //nolint:funlen
@@ -25,7 +24,7 @@ func NewApp(appName string) *cli.Command { //nolint:funlen
 		logLevelFlag = cli.StringFlag{
 			Name:     "log-level",
 			Value:    logger.InfoLevel.String(),
-			Usage:    "logging level (" + strings.Join(logger.LevelStrings(), "/") + ")",
+			Usage:    "Logging level (" + strings.Join(logger.LevelStrings(), "/") + ")",
 			Sources:  cli.EnvVars("LOG_LEVEL"),
 			OnlyOnce: true,
 			Config:   cli.StringConfig{TrimSpace: true},
@@ -41,7 +40,7 @@ func NewApp(appName string) *cli.Command { //nolint:funlen
 		logFormatFlag = cli.StringFlag{
 			Name:     "log-format",
 			Value:    logger.ConsoleFormat.String(),
-			Usage:    "logging format (" + strings.Join(logger.FormatStrings(), "/") + ")",
+			Usage:    "Logging format (" + strings.Join(logger.FormatStrings(), "/") + ")",
 			Sources:  cli.EnvVars("LOG_FORMAT"),
 			OnlyOnce: true,
 			Config:   cli.StringConfig{TrimSpace: true},
@@ -80,7 +79,7 @@ func NewApp(appName string) *cli.Command { //nolint:funlen
 			serve.NewCommand(log),
 			build.NewCommand(log),
 			healthcheck.NewCommand(log, healthcheck.NewHTTPHealthChecker()),
-			perftest.NewCommand(log),
+			perftest.NewCommand(),
 		},
 		Version: fmt.Sprintf("%s (%s)", appmeta.Version(), runtime.Version()),
 		Flags: []cli.Flag{ // global flags

internal/cli/app_generate.go

@@ -1,5 +1,4 @@
-//go:build ignore
-// +build ignore
+//go:build generate
 
 package main
 
@@ -17,8 +16,10 @@ func main() {
 	if stat, err := os.Stat(readmePath); err == nil && stat.Mode().IsRegular() {
 		if err = cliDocs.ToTabularToFileBetweenTags(cli.NewApp(""), "error-pages", readmePath); err != nil {
 			panic(err)
+		} else {
+			println("✔ cli docs updated successfully")
 		}
 	} else if err != nil {
-		println("readme file not found, cli docs not updated:", err.Error())
+		println("⚠ readme file not found, cli docs not updated:", err.Error())
 	}
 }

internal/cli/build/command.go

@@ -39,21 +39,24 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
 		cmd command
 		cfg = config.New()
 
-		addTplFlag      = shared.AddTemplatesFlag
-		disableTplFlag  = shared.DisableTemplateNamesFlag
-		addCodeFlag     = shared.AddHTTPCodesFlag
-		disableL10nFlag = shared.DisableL10nFlag
-		createIndexFlag = cli.BoolFlag{
-			Name:    "index",
-			Aliases: []string{"i"},
-			Usage:   "generate index.html file with links to all error pages",
+		addTplFlag              = shared.AddTemplatesFlag
+		disableTplFlag          = shared.DisableTemplateNamesFlag
+		addCodeFlag             = shared.AddHTTPCodesFlag
+		disableL10nFlag         = shared.DisableL10nFlag
+		disableMinificationFlag = shared.DisableMinificationFlag
+		createIndexFlag         = cli.BoolFlag{
+			Name:     "index",
+			Aliases:  []string{"i"},
+			Usage:    "Generate index.html file with links to all error pages",
+			Category: shared.CategoryBuild,
 		}
 		targetDirFlag = cli.StringFlag{
 			Name:     "target-dir",
 			Aliases:  []string{"out", "dir", "o"},
-			Usage:    "directory to put the built error pages into",
+			Usage:    "Directory to put the built error pages into",
 			Value:    ".", // current directory by default
 			Config:   cli.StringConfig{TrimSpace: true},
+			Category: shared.CategoryBuild,
 			OnlyOnce: true,
 			Validator: func(dir string) error {
 				if dir == "" {
@@ -79,6 +82,7 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
 		Usage:   "Build the static error pages and put them into a specified directory",
 		Action: func(ctx context.Context, c *cli.Command) error {
 			cfg.L10n.Disable = c.Bool(disableL10nFlag.Name)
+			cfg.DisableMinification = c.Bool(disableMinificationFlag.Name)
 			cmd.opt.createIndex = c.Bool(createIndexFlag.Name)
 			cmd.opt.targetDirAbsPath, _ = filepath.Abs(c.String(targetDirFlag.Name)) // an error checked by [os.Stat] validator
 
@@ -138,13 +142,14 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
 			&disableL10nFlag,
 			&createIndexFlag,
 			&targetDirFlag,
+			&disableMinificationFlag,
 		},
 	}
 
 	return cmd.c
 }
 
-func (cmd *command) Run( //nolint:funlen
+func (cmd *command) Run( //nolint:funlen,gocognit
 	ctx context.Context,
 	log *logger.Logger,
 	cfg *config.Config,
@@ -170,13 +175,21 @@ func (cmd *command) Run( //nolint:funlen
 
 			var outFilePath = path.Join(cmd.opt.targetDirAbsPath, templateName, code+".html")
 
-			if content, renderErr := appTemplate.Render(templateContent, appTemplate.Props{
+			if content, renderErr := appTemplate.Render(templateContent, appTemplate.Props{ //nolint:nestif
 				Code:               uint16(codeAsUint),
 				Message:            codeDescription.Message,
 				Description:        codeDescription.Description,
 				L10nDisabled:       cfg.L10n.Disable,
 				ShowRequestDetails: false,
 			}); renderErr == nil {
+				if !cfg.DisableMinification {
+					if mini, minErr := appTemplate.MiniHTML(content); minErr != nil {
+						log.Warn("Cannot minify the content", logger.Error(minErr))
+					} else {
+						content = mini
+					}
+				}
+
 				if err := os.WriteFile(outFilePath, []byte(content), os.FileMode(0664)); err != nil { //nolint:mnd
 					return err
 				}

internal/cli/perftest/command.go

@@ -1,32 +1,59 @@
 package perftest
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
 	"io"
-	"math/rand"
-	"net/http"
+	"math"
+	"os"
+	"os/exec"
 	"runtime"
-	"sync"
-	"sync/atomic"
+	"strconv"
 	"time"
 
 	"github.com/urfave/cli/v3"
 
 	"gh.tarampamp.am/error-pages/internal/cli/shared"
-	"gh.tarampamp.am/error-pages/internal/logger"
 )
 
+const wrkOneCodeTestLua = `
+local formats = { 'application/json', 'application/xml', 'text/html', 'text/plain' }
+
+request = function()
+		wrk.headers["User-Agent"] = "wrk"
+    wrk.headers["X-Namespace"] = "NAMESPACE_" .. tostring(math.random(0, 99999999))
+    wrk.headers["X-Request-ID"] = "REQ_ID_" .. tostring(math.random(0, 99999999))
+    wrk.headers["Content-Type"] = formats[ math.random( 0, #formats - 1 ) ]
+
+    return wrk.format("GET", "/500.html?rnd=" .. tostring(math.random(0, 99999999)), nil, nil)
+end
+`
+
+//nolint:lll
+const bombDifferentCodes = `
+local formats = { 'application/json', 'application/xml', 'text/html', 'text/plain' }
+
+request = function()
+		wrk.headers["User-Agent"] = "wrk"
+    wrk.headers["X-Namespace"] = "NAMESPACE_" .. tostring(math.random(0, 99999999))
+    wrk.headers["X-Request-ID"] = "REQ_ID_" .. tostring(math.random(0, 99999999))
+    wrk.headers["Content-Type"] = formats[ math.random( 0, #formats - 1 ) ]
+
+    return wrk.format("GET", "/" .. tostring(math.random(400, 599)) .. ".html?rnd=" .. tostring(math.random(0, 99999999)), nil, nil)
+end
+`
+
 // NewCommand creates `perftest` command.
-func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
+func NewCommand() *cli.Command { //nolint:funlen
 	var (
 		portFlag     = shared.ListenPortFlag
 		durationFlag = cli.DurationFlag{
 			Name:    "duration",
 			Aliases: []string{"d"},
-			Usage:   "duration of the test",
-			Value:   10 * time.Second, //nolint:mnd
+			Usage:   "Duration of test",
+			Value:   15 * time.Second, //nolint:mnd
 			Validator: func(d time.Duration) error {
 				if d <= time.Second {
 					return errors.New("duration can't be less than 1 second")
@@ -38,11 +65,28 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
 		threadsFlag = cli.UintFlag{
 			Name:    "threads",
 			Aliases: []string{"t"},
-			Usage:   "number of threads",
-			Value:   max(2, uint64(runtime.NumCPU()/2)), //nolint:mnd
+			Usage:   "Number of threads to use",
+			Value:   max(2, uint64(math.Round(float64(runtime.NumCPU())/1.3))), //nolint:mnd
 			Validator: func(u uint64) error {
 				if u == 0 {
 					return errors.New("threads number can't be zero")
+				} else if u > math.MaxUint16 {
+					return errors.New("threads number can't be greater than 65535")
+				}
+
+				return nil
+			},
+		}
+		connectionsFlag = cli.UintFlag{
+			Name:    "connections",
+			Aliases: []string{"c"},
+			Usage:   "Number of connections to keep open",
+			Value:   max(16, uint64(runtime.NumCPU()*25)), //nolint:mnd
+			Validator: func(u uint64) error {
+				if u == 0 {
+					return errors.New("threads number can't be zero")
+				} else if u > math.MaxUint16 {
+					return errors.New("threads number can't be greater than 65535")
 				}
 
 				return nil
@@ -52,97 +96,47 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
 
 	return &cli.Command{
 		Name:    "perftest",
-		Aliases: []string{"perf", "test"},
+		Aliases: []string{"perf", "benchmark", "bench"},
 		Hidden:  true,
-		Usage:   "Simple performance (load) test for the HTTP server",
-		Action: func(ctx context.Context, c *cli.Command) error { // TODO: use fasthttp.Client
-			var (
-				perfCtx, cancel = context.WithTimeout(ctx, c.Duration(durationFlag.Name))
-				startedAt       = time.Now()
-
-				wg      sync.WaitGroup
-				success atomic.Uint64
-				failed  atomic.Uint64
-			)
-
-			defer func() {
-				cancel()
-
-				log.Info("Summary",
-					logger.Uint64("success", success.Load()),
-					logger.Uint64("failed", failed.Load()),
-					logger.Duration("duration", time.Since(startedAt)),
-					logger.Float64("RPS", float64(success.Load()+failed.Load())/time.Since(startedAt).Seconds()),
-					logger.Float64("errors rate", float64(failed.Load())/float64(success.Load()+failed.Load())*100), //nolint:mnd
-				)
-			}()
-
-			log.Info("Running test",
-				logger.Uint64("threads", c.Uint(threadsFlag.Name)),
-				logger.Duration("duration", c.Duration(durationFlag.Name)),
-			)
-
-			var httpClient = &http.Client{
-				Transport: &http.Transport{MaxConnsPerHost: max(2, int(c.Uint(threadsFlag.Name))-1)}, //nolint:mnd
-				Timeout:   c.Duration(durationFlag.Name) + time.Second,
+		Usage:   "Performance (load) test for the HTTP server (locally installed wrk is required)",
+		Action: func(ctx context.Context, c *cli.Command) error {
+			var wrkBinPath, lErr = exec.LookPath("wrk")
+			if lErr != nil {
+				return fmt.Errorf("seems like wrk (https://github.com/wg/wrk) is not installed: %w", lErr)
 			}
 
-			for i := uint64(0); i < c.Uint(threadsFlag.Name); i++ {
-				wg.Add(1)
+			var runTest = func(scriptContent string) error {
+				if stdOut, stdErr, err := wrkRunTest(ctx,
+					wrkBinPath,
+					uint16(c.Uint(threadsFlag.Name)),
+					uint16(c.Uint(connectionsFlag.Name)),
+					c.Duration(durationFlag.Name),
+					uint16(c.Uint(portFlag.Name)),
+					scriptContent,
+				); err != nil {
+					var errData, _ = io.ReadAll(stdErr)
 
-				go func(log *logger.Logger) {
-					defer wg.Done()
+					return fmt.Errorf("failed to execute the test: %w (%s)", err, string(errData))
+				} else {
+					var outData, _ = io.ReadAll(stdOut)
 
-					if perfCtx.Err() != nil {
-						return
-					}
+					printf("Test completed successfully. Here is the output:\n\n%s\n", string(outData))
+				}
 
-					var req, rErr = makeRequest(perfCtx, uint16(c.Uint(portFlag.Name)))
-					if rErr != nil {
-						log.Error("Failed to create a new request", logger.Error(rErr))
-
-						return
-					}
-
-					for {
-						var sentAt = time.Now()
-
-						var resp, respErr = httpClient.Do(req)
-						if resp != nil {
-							if _, err := io.Copy(io.Discard, resp.Body); err != nil && !errIsDone(err) {
-								log.Error("Failed to read response body", logger.Error(err))
-							}
-
-							if err := resp.Body.Close(); err != nil && !errIsDone(err) {
-								log.Error("Failed to close response body", logger.Error(err))
-							}
-						}
-
-						if respErr != nil {
-							if errIsDone(respErr) {
-								return
-							}
-
-							log.Error("Request failed", logger.Error(respErr))
-							failed.Add(1)
-
-							continue
-						}
-
-						log.Debug("Response received",
-							logger.String("status", resp.Status),
-							logger.Duration("duration", time.Since(sentAt)),
-							logger.Int64("size", resp.ContentLength),
-							logger.Uint64("success", success.Load()),
-							logger.Uint64("failed", failed.Load()),
-						)
-
-						success.Add(1)
-					}
-				}(log.Named(fmt.Sprintf("thread-%d", i)))
+				return nil
 			}
 
-			wg.Wait()
+			printf("Starting the test to bomb ONE PAGE (code). Please, be patient...\n")
+
+			if err := runTest(wrkOneCodeTestLua); err != nil {
+				return err
+			}
+
+			printf("Starting the test to bomb DIFFERENT PAGES (codes). Please, be patient...\n")
+
+			if err := runTest(bombDifferentCodes); err != nil {
+				return err
+			}
 
 			return nil
 		},
@@ -150,54 +144,51 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit
 			&portFlag,
 			&durationFlag,
 			&threadsFlag,
+			&connectionsFlag,
 		},
 	}
 }
 
-// randomIntBetween returns a random integer between min and max.
-func randomIntBetween(min, max int) int { return min + rand.Intn(max-min) } //nolint:gosec
+func printf(format string, args ...any) { fmt.Printf(format, args...) } //nolint:forbidigo
 
-// makeRequest creates a new HTTP request for the performance test.
-func makeRequest(ctx context.Context, port uint16) (*http.Request, error) {
-	var req, rErr = http.NewRequestWithContext(ctx,
-		http.MethodGet,
-		fmt.Sprintf(
-			"http://127.0.0.1:%d/%d.html?rnd=%d", // for load testing purposes only
-			port,
-			randomIntBetween(400, 418),       //nolint:mnd
-			randomIntBetween(1, 999_999_999), //nolint:mnd
-		),
-		http.NoBody,
+func wrkRunTest(
+	ctx context.Context,
+	wrkBinPath string,
+	threadsCount, connectionsCount uint16,
+	duration time.Duration,
+	port uint16,
+	scriptContent string,
+) (io.Reader, io.Reader, error) {
+	var tmpFile, tErr = os.CreateTemp("", "ep-perf-one-page")
+	if tErr != nil {
+		return nil, nil, fmt.Errorf("failed to create a temporary file: %w", tErr)
+	}
+
+	defer func() {
+		_ = tmpFile.Close()
+		_ = os.Remove(tmpFile.Name())
+	}()
+
+	if _, err := tmpFile.WriteString(scriptContent); err != nil {
+		return nil, nil, fmt.Errorf("failed to write to a temporary file: %w", err)
+	}
+
+	if err := tmpFile.Close(); err != nil {
+		return nil, nil, err
+	}
+
+	var stdout, stderr bytes.Buffer
+
+	var cmd = exec.CommandContext(ctx, wrkBinPath, //nolint:gosec
+		"--timeout", "1s",
+		"--threads", strconv.FormatUint(uint64(threadsCount), 10),
+		"--connections", strconv.FormatUint(uint64(connectionsCount), 10),
+		"--duration", duration.String(),
+		"--script", tmpFile.Name(),
+		fmt.Sprintf("http://127.0.0.1:%d/", port),
 	)
 
-	if rErr != nil {
-		return nil, rErr
-	}
+	cmd.Stdout, cmd.Stderr = &stdout, &stderr
 
-	req.Header.Set("Connection", "keep-alive")
-	req.Header.Set("User-Agent", "perftest")
-	req.Header.Set("X-Namespace", fmt.Sprintf("namespace-%d", randomIntBetween(1, 999_999_999))) //nolint:mnd
-	req.Header.Set("X-Request-ID", fmt.Sprintf("req-id-%d", randomIntBetween(1, 999_999_999)))   //nolint:mnd
-
-	var contentType string
-
-	switch randomIntBetween(1, 4) { //nolint:mnd
-	case 1:
-		contentType = "application/json"
-	case 2: //nolint:mnd
-		contentType = "application/xml"
-	case 3: //nolint:mnd
-		contentType = "text/html"
-	default:
-		contentType = "text/plain"
-	}
-
-	req.Header.Set("Content-Type", contentType)
-
-	return req, nil
-}
-
-// errIsDone checks if the error is a context.DeadlineExceeded or context.Canceled.
-func errIsDone(err error) bool {
-	return errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled)
+	return &stdout, &stderr, cmd.Run() // execute
 }

internal/cli/serve/command.go

@@ -22,9 +22,9 @@ type command struct {
 
 	opt struct {
 		http struct { // our HTTP server
-			addr string
-			port uint16
-			// readBufferSize uint
+			addr           string
+			port           uint16
+			readBufferSize uint
 		}
 	}
 }
@@ -38,33 +38,37 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 	)
 
 	var (
-		addrFlag        = shared.ListenAddrFlag
-		portFlag        = shared.ListenPortFlag
-		addTplFlag      = shared.AddTemplatesFlag
-		disableTplFlag  = shared.DisableTemplateNamesFlag
-		addCodeFlag     = shared.AddHTTPCodesFlag
-		disableL10nFlag = shared.DisableL10nFlag
-		jsonFormatFlag  = cli.StringFlag{
+		addrFlag                = shared.ListenAddrFlag
+		portFlag                = shared.ListenPortFlag
+		addTplFlag              = shared.AddTemplatesFlag
+		disableTplFlag          = shared.DisableTemplateNamesFlag
+		addCodeFlag             = shared.AddHTTPCodesFlag
+		disableL10nFlag         = shared.DisableL10nFlag
+		disableMinificationFlag = shared.DisableMinificationFlag
+		jsonFormatFlag          = cli.StringFlag{
 			Name: "json-format",
-			Usage: "override the default error page response in JSON format (Go templates are supported; the error " +
+			Usage: "Override the default error page response in JSON format (Go templates are supported; the error " +
 				"page will use this template if the client requests JSON content type)",
 			Sources:  env("RESPONSE_JSON_FORMAT"),
+			Category: shared.CategoryFormats,
 			OnlyOnce: true,
 			Config:   trim,
 		}
 		xmlFormatFlag = cli.StringFlag{
 			Name: "xml-format",
-			Usage: "override the default error page response in XML format (Go templates are supported; the error " +
+			Usage: "Override the default error page response in XML format (Go templates are supported; the error " +
 				"page will use this template if the client requests XML content type)",
 			Sources:  env("RESPONSE_XML_FORMAT"),
+			Category: shared.CategoryFormats,
 			OnlyOnce: true,
 			Config:   trim,
 		}
 		plainTextFormatFlag = cli.StringFlag{
 			Name: "plaintext-format",
-			Usage: "override the default error page response in plain text format (Go templates are supported; the " +
+			Usage: "Override the default error page response in plain text format (Go templates are supported; the " +
 				"error page will use this template if the client requests plain text content type or does not specify any)",
 			Sources:  env("RESPONSE_PLAINTEXT_FORMAT"),
+			Category: shared.CategoryFormats,
 			OnlyOnce: true,
 			Config:   trim,
 		}
@@ -72,17 +76,19 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 			Name:    "template-name",
 			Aliases: []string{"t"},
 			Value:   cfg.TemplateName,
-			Usage: "name of the template to use for rendering error pages (built-in templates: " +
+			Usage: "Name of the template to use for rendering error pages (built-in templates: " +
 				strings.Join(cfg.Templates.Names(), ", ") + ")",
 			Sources:  env("TEMPLATE_NAME"),
+			Category: shared.CategoryTemplates,
 			OnlyOnce: true,
 			Config:   trim,
 		}
 		defaultCodeToRenderFlag = cli.UintFlag{
-			Name:    "default-error-page",
-			Usage:   "the code of the default (index page, when a code is not specified) error page to render",
-			Value:   uint64(cfg.DefaultCodeToRender),
-			Sources: env("DEFAULT_ERROR_PAGE"),
+			Name:     "default-error-page",
+			Usage:    "The code of the default (index page, when a code is not specified) error page to render",
+			Value:    uint64(cfg.DefaultCodeToRender),
+			Sources:  env("DEFAULT_ERROR_PAGE"),
+			Category: shared.CategoryCodes,
 			Validator: func(code uint64) error {
 				if code > 999 { //nolint:mnd
 					return fmt.Errorf("wrong HTTP code [%d] for the default error page", code)
@@ -94,17 +100,19 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 		}
 		sendSameHTTPCodeFlag = cli.BoolFlag{
 			Name: "send-same-http-code",
-			Usage: "the HTTP response should have the same status code as the requested error page (by default, " +
+			Usage: "The HTTP response should have the same status code as the requested error page (by default, " +
 				"every response with an error page will have a status code of 200)",
 			Value:    cfg.RespondWithSameHTTPCode,
 			Sources:  env("SEND_SAME_HTTP_CODE"),
+			Category: shared.CategoryOther,
 			OnlyOnce: true,
 		}
 		showDetailsFlag = cli.BoolFlag{
 			Name:     "show-details",
-			Usage:    "show request details in the error page response (if supported by the template)",
+			Usage:    "Show request details in the error page response (if supported by the template)",
 			Value:    cfg.ShowDetails,
 			Sources:  env("SHOW_DETAILS"),
+			Category: shared.CategoryOther,
 			OnlyOnce: true,
 		}
 		proxyHeadersListFlag = cli.StringFlag{
@@ -122,14 +130,16 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 
 				return nil
 			},
+			Category: shared.CategoryOther,
 			OnlyOnce: true,
 			Config:   trim,
 		}
 		rotationModeFlag = cli.StringFlag{
 			Name:     "rotation-mode",
 			Value:    config.RotationModeDisabled.String(),
-			Usage:    "templates automatic rotation mode (" + strings.Join(config.RotationModeStrings(), "/") + ")",
+			Usage:    "Templates automatic rotation mode (" + strings.Join(config.RotationModeStrings(), "/") + ")",
 			Sources:  env("TEMPLATES_ROTATION_MODE"),
+			Category: shared.CategoryTemplates,
 			OnlyOnce: true,
 			Config:   trim,
 			Validator: func(s string) error {
@@ -140,28 +150,40 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 				return nil
 			},
 		}
+		readBufferSizeFlag = cli.UintFlag{
+			Name: "read-buffer-size",
+			Usage: "Per-connection buffer size in bytes for reading requests, this also limits the maximum header size " +
+				"(increase this buffer if your clients send multi-KB Request URIs and/or multi-KB headers (e.g., " +
+				"large cookies), note that increasing this value will increase memory consumption)",
+			Value:    1024 * 5, //nolint:mnd // 5 KB
+			Sources:  env("READ_BUFFER_SIZE"),
+			Category: shared.CategoryOther,
+			OnlyOnce: true,
+		}
 	)
 
 	// override some flag usage messages
-	addrFlag.Usage = "the HTTP server will listen on this IP (v4 or v6) address (set 127.0.0.1 for localhost, " +
+	addrFlag.Usage = "The HTTP server will listen on this IP (v4 or v6) address (set 127.0.0.1/::1 for localhost, " +
 		"0.0.0.0 to listen on all interfaces, or specify a custom IP)"
-	portFlag.Usage = "the TCP port number for the HTTP server to listen on (0-65535)"
+	portFlag.Usage = "The TCP port number for the HTTP server to listen on (0-65535)"
 
 	disableL10nFlag.Value = cfg.L10n.Disable // set the default value depending on the configuration
 
 	cmd.c = &cli.Command{
 		Name:    "serve",
 		Aliases: []string{"s", "server", "http"},
-		Usage:   "Start HTTP server",
+		Usage:   "Please start the HTTP server to serve the error pages. You can configure various options - please RTFM :D",
 		Suggest: true,
 		Action: func(ctx context.Context, c *cli.Command) error {
 			cmd.opt.http.addr = c.String(addrFlag.Name)
 			cmd.opt.http.port = uint16(c.Uint(portFlag.Name))
+			cmd.opt.http.readBufferSize = uint(c.Uint(readBufferSizeFlag.Name))
 			cfg.L10n.Disable = c.Bool(disableL10nFlag.Name)
 			cfg.DefaultCodeToRender = uint16(c.Uint(defaultCodeToRenderFlag.Name))
 			cfg.RespondWithSameHTTPCode = c.Bool(sendSameHTTPCodeFlag.Name)
 			cfg.RotationMode, _ = config.ParseRotationMode(c.String(rotationModeFlag.Name))
 			cfg.ShowDetails = c.Bool(showDetailsFlag.Name)
+			cfg.DisableMinification = c.Bool(disableMinificationFlag.Name)
 
 			{ // override default JSON, XML, and PlainText formats
 				if c.IsSet(jsonFormatFlag.Name) {
@@ -282,6 +304,8 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 			&showDetailsFlag,
 			&proxyHeadersListFlag,
 			&rotationModeFlag,
+			&readBufferSizeFlag,
+			&disableMinificationFlag,
 		},
 	}
 
@@ -290,7 +314,7 @@ func NewCommand(log *logger.Logger) *cli.Command { //nolint:funlen,gocognit,gocy
 
 // Run current command.
 func (cmd *command) Run(ctx context.Context, log *logger.Logger, cfg *config.Config) error { //nolint:funlen
-	var srv = appHttp.NewServer(log)
+	var srv = appHttp.NewServer(log, cmd.opt.http.readBufferSize)
 
 	if err := srv.Register(cfg); err != nil {
 		return err

internal/cli/serve/command_test.go

@@ -36,7 +36,7 @@ func TestCommand_Run(t *testing.T) {
 			"--add-template", "./testdata/foo-template.html",
 			"--disable-template", "ghost",
 			"--disable-template", "<unknown>",
-			"--add-http-code", "200=Code/Description",
+			"--add-code", "200=Code/Description",
 			"--json-format", "json format",
 			"--xml-format", "xml format",
 			"--plaintext-format", "plaintext format",

internal/cli/shared/flags.go

@@ -11,6 +11,15 @@ import (
 	"gh.tarampamp.am/error-pages/internal/config"
 )
 
+const (
+	CategoryHTTP      = "HTTP:"
+	CategoryTemplates = "TEMPLATES:"
+	CategoryCodes     = "HTTP CODES:"
+	CategoryFormats   = "FORMATS:"
+	CategoryBuild     = "BUILD:"
+	CategoryOther     = "OTHER:"
+)
+
 // Note: Don't use pointers for flags, because they have own state which is not thread-safe.
 // https://github.com/urfave/cli/issues/1926
 
@@ -20,6 +29,7 @@ var ListenAddrFlag = cli.StringFlag{
 	Usage:    "IP (v4 or v6) address to listen on",
 	Value:    "0.0.0.0", // bind to all interfaces by default
 	Sources:  cli.EnvVars("LISTEN_ADDR"),
+	Category: CategoryHTTP,
 	OnlyOnce: true,
 	Config:   cli.StringConfig{TrimSpace: true},
 	Validator: func(ip string) error {
@@ -41,6 +51,7 @@ var ListenPortFlag = cli.UintFlag{
 	Usage:    "TCP port number",
 	Value:    8080, // default port number
 	Sources:  cli.EnvVars("LISTEN_PORT"),
+	Category: CategoryHTTP,
 	OnlyOnce: true,
 	Validator: func(port uint64) error {
 		if port == 0 || port > 65535 {
@@ -53,9 +64,11 @@ var ListenPortFlag = cli.UintFlag{
 
 var AddTemplatesFlag = cli.StringSliceFlag{
 	Name: "add-template",
-	Usage: "to add a new template, provide the path to the file using this flag (the filename without the extension " +
+	Usage: "To add a new template, provide the path to the file using this flag (the filename without the extension " +
 		"will be used as the template name)",
-	Config: cli.StringConfig{TrimSpace: true},
+	Config:   cli.StringConfig{TrimSpace: true},
+	Sources:  cli.EnvVars("ADD_TEMPLATE"),
+	Category: CategoryTemplates,
 	Validator: func(paths []string) error {
 		for _, path := range paths {
 			if path == "" {
@@ -72,18 +85,19 @@ var AddTemplatesFlag = cli.StringSliceFlag{
 }
 
 var DisableTemplateNamesFlag = cli.StringSliceFlag{
-	Name:   "disable-template",
-	Usage:  "disable the specified template by its name (useful to disable the built-in templates and use only custom ones)",
-	Config: cli.StringConfig{TrimSpace: true},
+	Name:     "disable-template",
+	Usage:    "Disable the specified template by its name (useful to disable the built-in templates and use only custom ones)",
+	Config:   cli.StringConfig{TrimSpace: true},
+	Category: CategoryTemplates,
 }
 
 var AddHTTPCodesFlag = cli.StringMapFlag{
-	Name:    "add-http-code",
-	Aliases: []string{"add-code"},
-	Usage: "to add a new HTTP status code, provide the code and its message/description using this flag (the format " +
+	Name: "add-code",
+	Usage: "To add a new HTTP status code, provide the code and its message/description using this flag (the format " +
 		"should be '%code%=%message%/%description%'; the code may contain a wildcard '*' to cover multiple codes at " +
 		"once, for example, '4**' will cover all 4xx codes unless a more specific code is described previously)",
-	Config: cli.StringConfig{TrimSpace: true},
+	Config:   cli.StringConfig{TrimSpace: true},
+	Category: CategoryCodes,
 	Validator: func(codes map[string]string) error {
 		for code, msgAndDesc := range codes {
 			if code == "" {
@@ -128,7 +142,16 @@ func ParseHTTPCodes(codes map[string]string) map[string]config.CodeDescription {
 
 var DisableL10nFlag = cli.BoolFlag{
 	Name:     "disable-l10n",
-	Usage:    "disable localization of error pages (if the template supports localization)",
+	Usage:    "Disable localization of error pages (if the template supports localization)",
 	Sources:  cli.EnvVars("DISABLE_L10N"),
+	Category: CategoryOther,
+	OnlyOnce: true,
+}
+
+var DisableMinificationFlag = cli.BoolFlag{
+	Name:     "disable-minification",
+	Usage:    "Disable the minification of HTML pages, including CSS, SVG, and JS (may be useful for debugging)",
+	Sources:  cli.EnvVars("DISABLE_MINIFICATION"),
+	Category: CategoryOther,
 	OnlyOnce: true,
 }

internal/cli/shared/flags_test.go

@@ -91,6 +91,7 @@ func TestAddTemplatesFlag(t *testing.T) {
 	var flag = shared.AddTemplatesFlag
 
 	assert.Equal(t, "add-template", flag.Name)
+	assert.Contains(t, flag.Sources.String(), "ADD_TEMPLATE")
 
 	for wantErrMsg, giveValue := range map[string][]string{
 		"missing template path":     {""},
@@ -122,7 +123,7 @@ func TestAddHTTPCodesFlag(t *testing.T) {
 
 	var flag = shared.AddHTTPCodesFlag
 
-	assert.Equal(t, "add-http-code", flag.Name)
+	assert.Equal(t, "add-code", flag.Name)
 
 	for name, tt := range map[string]struct {
 		giveValue  map[string]string
@@ -216,3 +217,12 @@ func TestDisableL10nFlag(t *testing.T) {
 	assert.Equal(t, "disable-l10n", flag.Name)
 	assert.Contains(t, flag.Sources.String(), "DISABLE_L10N")
 }
+
+func TestDisableMinificationFlag(t *testing.T) {
+	t.Parallel()
+
+	var flag = shared.DisableMinificationFlag
+
+	assert.Equal(t, "disable-minification", flag.Name)
+	assert.Contains(t, flag.Sources.String(), "DISABLE_MINIFICATION")
+}

internal/config/config.go

@@ -56,6 +56,9 @@ type Config struct {
 	// ShowDetails determines whether to show additional details in the error response, extracted from the
 	// incoming request (if supported by the template).
 	ShowDetails bool
+
+	// DisableMinification determines whether to disable minification of the rendered content (e.g., HTML, CSS) or not.
+	DisableMinification bool
 }
 
 const defaultJSONFormat string = `{
@@ -72,7 +75,7 @@ const defaultJSONFormat string = `{
     "service_name": {{ service_name | json }},
     "service_port": {{ service_port | json }},
     "request_id": {{ request_id | json }},
-    "timestamp": {{ now.Unix }}
+    "timestamp": {{ nowUnix }}
   }{{ end }}
 }
 ` // an empty line at the end is important for better UX
@@ -91,7 +94,7 @@ const defaultXMLFormat string = `<?xml version="1.0" encoding="utf-8"?>
     <serviceName>{{ service_name }}</serviceName>
     <servicePort>{{ service_port }}</servicePort>
     <requestID>{{ request_id }}</requestID>
-    <timestamp>{{ now.Unix }}</timestamp>
+    <timestamp>{{ nowUnix }}</timestamp>
   </details>{{ end }}
 </error>
 ` // an empty line at the end is important for better UX
@@ -107,7 +110,7 @@ Ingress Name: {{ ingress_name }}
 Service Name: {{ service_name }}
 Service Port: {{ service_port }}
 Request ID: {{ request_id }}
-Timestamp: {{ now.Unix }}{{ end }}
+Timestamp: {{ nowUnix }}{{ end }}
 ` // an empty line at the end is important for better UX
 
 //nolint:lll

internal/config/config_test.go

@@ -24,6 +24,7 @@ func TestNew(t *testing.T) {
 		assert.NotEmpty(t, cfg.TemplateName)
 		assert.True(t, cfg.Templates.Has(cfg.TemplateName))
 		assert.Equal(t, uint16(http.StatusNotFound), cfg.DefaultCodeToRender)
+		assert.False(t, cfg.DisableMinification)
 	})
 
 	t.Run("changing cfg1 should not affect cfg2", func(t *testing.T) {

internal/http/handlers/error_page/cache.go

@@ -0,0 +1,111 @@
+package error_page
+
+import (
+	"bytes"
+	"crypto/md5" //nolint:gosec
+	"encoding/gob"
+	"sync"
+	"time"
+
+	"gh.tarampamp.am/error-pages/internal/template"
+)
+
+type (
+	// RenderedCache is a cache for rendered error pages. It's safe for concurrent use.
+	// It uses a hash of the template and props as a key.
+	//
+	// To remove expired items, call ClearExpired method periodically (a bit more often than the ttl).
+	RenderedCache struct {
+		ttl time.Duration
+
+		mu    sync.RWMutex
+		items map[[32]byte]cacheItem // map[template_hash[0:15];props_hash[16:32]]cache_item
+	}
+
+	cacheItem struct {
+		content     []byte
+		addedAtNano int64
+	}
+)
+
+// NewRenderedCache creates a new RenderedCache with the specified ttl.
+func NewRenderedCache(ttl time.Duration) *RenderedCache {
+	return &RenderedCache{ttl: ttl, items: make(map[[32]byte]cacheItem)}
+}
+
+// genKey generates a key for the cache item by hashing the template and props.
+func (rc *RenderedCache) genKey(template string, props template.Props) [32]byte {
+	var (
+		key    [32]byte
+		th, ph = hash(template), hash(props) // template hash, props hash
+	)
+
+	copy(key[:16], th[:]) // first 16 bytes for the template hash
+	copy(key[16:], ph[:]) // last 16 bytes for the props hash
+
+	return key
+}
+
+// Has checks if the cache has an item with the specified template and props.
+func (rc *RenderedCache) Has(template string, props template.Props) bool {
+	var key = rc.genKey(template, props)
+
+	rc.mu.RLock()
+	_, ok := rc.items[key]
+	rc.mu.RUnlock()
+
+	return ok
+}
+
+// Put adds a new item to the cache with the specified template, props, and content.
+func (rc *RenderedCache) Put(template string, props template.Props, content []byte) {
+	var key = rc.genKey(template, props)
+
+	rc.mu.Lock()
+	rc.items[key] = cacheItem{content: content, addedAtNano: time.Now().UnixNano()}
+	rc.mu.Unlock()
+}
+
+// Get returns the content of the item with the specified template and props.
+func (rc *RenderedCache) Get(template string, props template.Props) ([]byte, bool) {
+	var key = rc.genKey(template, props)
+
+	rc.mu.RLock()
+	item, ok := rc.items[key]
+	rc.mu.RUnlock()
+
+	return item.content, ok
+}
+
+// ClearExpired removes all expired items from the cache.
+func (rc *RenderedCache) ClearExpired() {
+	rc.mu.Lock()
+
+	var now = time.Now().UnixNano()
+
+	for key, item := range rc.items {
+		if now-item.addedAtNano > rc.ttl.Nanoseconds() {
+			delete(rc.items, key)
+		}
+	}
+
+	rc.mu.Unlock()
+}
+
+// Clear removes all items from the cache.
+func (rc *RenderedCache) Clear() {
+	rc.mu.Lock()
+	clear(rc.items)
+	rc.mu.Unlock()
+}
+
+// hash returns an MD5 hash of the provided value (it may be any built-in type).
+func hash(in any) [16]byte {
+	var b bytes.Buffer
+
+	if err := gob.NewEncoder(&b).Encode(in); err != nil {
+		return [16]byte{} // never happens because we encode only built-in types
+	}
+
+	return md5.Sum(b.Bytes()) //nolint:gosec
+}

internal/http/handlers/error_page/cache_test.go

@@ -0,0 +1,86 @@
+package error_page_test
+
+import (
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"gh.tarampamp.am/error-pages/internal/http/handlers/error_page"
+	"gh.tarampamp.am/error-pages/internal/template"
+)
+
+func TestRenderedCache_CRUD(t *testing.T) {
+	t.Parallel()
+
+	var cache = error_page.NewRenderedCache(time.Millisecond)
+
+	t.Run("has", func(t *testing.T) {
+		assert.False(t, cache.Has("template", template.Props{}))
+		cache.Put("template", template.Props{}, []byte("content"))
+		assert.True(t, cache.Has("template", template.Props{}))
+
+		assert.False(t, cache.Has("template", template.Props{Code: 1}))
+		assert.False(t, cache.Has("foo", template.Props{Code: 1}))
+	})
+
+	t.Run("exists", func(t *testing.T) {
+		var got, ok = cache.Get("template", template.Props{})
+
+		assert.True(t, ok)
+		assert.Equal(t, []byte("content"), got)
+
+		cache.Clear()
+
+		assert.False(t, cache.Has("template", template.Props{}))
+	})
+
+	t.Run("not exists", func(t *testing.T) {
+		var got, ok = cache.Get("template", template.Props{Code: 2})
+
+		assert.False(t, ok)
+		assert.Nil(t, got)
+	})
+
+	t.Run("race condition provocation", func(t *testing.T) {
+		var wg sync.WaitGroup
+
+		for i := 0; i < 100; i++ {
+			wg.Add(2)
+
+			go func(i int) {
+				defer wg.Done()
+
+				cache.Get("template", template.Props{})
+				cache.Put("template"+strconv.Itoa(i), template.Props{}, []byte("content"))
+				cache.Has("template", template.Props{})
+			}(i)
+
+			go func() {
+				defer wg.Done()
+
+				cache.ClearExpired()
+			}()
+		}
+
+		wg.Wait()
+	})
+}
+
+func TestRenderedCache_Expiring(t *testing.T) {
+	t.Parallel()
+
+	var cache = error_page.NewRenderedCache(10 * time.Millisecond)
+
+	cache.Put("template", template.Props{}, []byte("content"))
+	cache.ClearExpired()
+	assert.True(t, cache.Has("template", template.Props{}))
+
+	<-time.After(10 * time.Millisecond)
+
+	assert.True(t, cache.Has("template", template.Props{})) // expired, but not cleared yet
+	cache.ClearExpired()
+	assert.False(t, cache.Has("template", template.Props{})) // cleared
+}

internal/http/handlers/error_page/handler.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"sync"
 	"sync/atomic"
 	"time"
 
@@ -15,7 +16,32 @@ import (
 )
 
 // New creates a new handler that returns an error page with the specified status code and format.
-func New(cfg *config.Config, log *logger.Logger) fasthttp.RequestHandler { //nolint:funlen,gocognit,gocyclo
+func New(cfg *config.Config, log *logger.Logger) (_ fasthttp.RequestHandler, closeCache func()) { //nolint:funlen,gocognit,gocyclo,lll
+	// if the ttl will be bigger than 1 second, the template functions like `nowUnix` will not work as expected
+	const cacheTtl = 900 * time.Millisecond // the cache TTL
+
+	var (
+		cache, stopCh = NewRenderedCache(cacheTtl), make(chan struct{})
+		stopOnce      sync.Once
+	)
+
+	// run a goroutine that will clear the cache from expired items. to stop the goroutine - close the stop channel
+	// or call the closeCache
+	go func() {
+		var timer = time.NewTimer(cacheTtl)
+		defer func() { timer.Stop(); cache.Clear() }()
+
+		for {
+			select {
+			case <-timer.C:
+				cache.ClearExpired()
+				timer.Reset(cacheTtl)
+			case <-stopCh:
+				return
+			}
+		}
+	}()
+
 	return func(ctx *fasthttp.RequestCtx) {
 		var (
 			reqHeaders = &ctx.Request.Header
@@ -106,57 +132,90 @@ func New(cfg *config.Config, log *logger.Logger) fasthttp.RequestHandler { //nol
 
 		switch {
 		case format == jsonFormat && cfg.Formats.JSON != "":
-			if content, err := template.Render(cfg.Formats.JSON, tplProps); err != nil {
-				j, _ := json.Marshal(fmt.Sprintf("Failed to render the JSON template: %s", err.Error()))
-				write(ctx, log, j)
-			} else {
-				write(ctx, log, content)
+			if cached, ok := cache.Get(cfg.Formats.JSON, tplProps); ok { // cache hit
+				write(ctx, log, cached)
+			} else { // cache miss
+				if content, err := template.Render(cfg.Formats.JSON, tplProps); err != nil {
+					errAsJson, _ := json.Marshal(fmt.Sprintf("Failed to render the JSON template: %s", err.Error()))
+					write(ctx, log, errAsJson) // error during rendering
+				} else {
+					cache.Put(cfg.Formats.JSON, tplProps, []byte(content))
+
+					write(ctx, log, content) // rendered successfully
+				}
 			}
 
 		case format == xmlFormat && cfg.Formats.XML != "":
-			if content, err := template.Render(cfg.Formats.XML, tplProps); err != nil {
-				write(ctx, log, fmt.Sprintf(
-					"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<error>Failed to render the XML template: %s</error>", err.Error(),
-				))
-			} else {
-				write(ctx, log, content)
+			if cached, ok := cache.Get(cfg.Formats.XML, tplProps); ok { // cache hit
+				write(ctx, log, cached)
+			} else { // cache miss
+				if content, err := template.Render(cfg.Formats.XML, tplProps); err != nil {
+					write(ctx, log, fmt.Sprintf(
+						"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<error>Failed to render the XML template: %s</error>\n", err.Error(),
+					))
+				} else {
+					cache.Put(cfg.Formats.XML, tplProps, []byte(content))
+
+					write(ctx, log, content)
+				}
 			}
 
 		case format == htmlFormat:
 			var templateName = templateToUse(cfg)
 
-			if tpl, found := cfg.Templates.Get(templateName); found {
-				if content, err := template.Render(tpl, tplProps); err != nil {
-					// TODO: add GZIP compression for the HTML content support
-					write(ctx, log, fmt.Sprintf(
-						"<!DOCTYPE html>\n<html><body>Failed to render the HTML template %s: %s</body></html>",
-						templateName,
-						err.Error(),
-					))
-				} else {
-					write(ctx, log, content)
+			if tpl, found := cfg.Templates.Get(templateName); found { //nolint:nestif
+				if cached, ok := cache.Get(tpl, tplProps); ok { // cache hit
+					write(ctx, log, cached)
+				} else { // cache miss
+					if content, err := template.Render(tpl, tplProps); err != nil {
+						// TODO: add GZIP compression for the HTML content support
+						write(ctx, log, fmt.Sprintf(
+							"<!DOCTYPE html>\n<html><body>Failed to render the HTML template %s: %s</body></html>\n",
+							templateName,
+							err.Error(),
+						))
+					} else {
+						if !cfg.DisableMinification {
+							if mini, minErr := template.MiniHTML(content); minErr != nil {
+								log.Warn("HTML minification failed", logger.Error(minErr))
+							} else {
+								content = mini
+							}
+						}
+
+						cache.Put(tpl, tplProps, []byte(content))
+
+						write(ctx, log, content)
+					}
 				}
 			} else {
 				write(ctx, log, fmt.Sprintf(
-					"<!DOCTYPE html>\n<html><body>Template %s not found and cannot be used</body></html>", templateName,
+					"<!DOCTYPE html>\n<html><body>Template %s not found and cannot be used</body></html>\n", templateName,
 				))
 			}
 
 		default: // plainTextFormat as default
-			if cfg.Formats.PlainText != "" {
-				if content, err := template.Render(cfg.Formats.PlainText, tplProps); err != nil {
-					write(ctx, log, fmt.Sprintf("Failed to render the PlainText template: %s", err.Error()))
-				} else {
-					write(ctx, log, content)
+			if cfg.Formats.PlainText != "" { //nolint:nestif
+				if cached, ok := cache.Get(cfg.Formats.PlainText, tplProps); ok { // cache hit
+					write(ctx, log, cached)
+				} else { // cache miss
+					if content, err := template.Render(cfg.Formats.PlainText, tplProps); err != nil {
+						write(ctx, log, fmt.Sprintf("Failed to render the PlainText template: %s", err.Error()))
+					} else {
+						cache.Put(cfg.Formats.PlainText, tplProps, []byte(content))
+
+						write(ctx, log, content)
+					}
 				}
 			} else {
 				write(ctx, log, `The requested content format is not supported.
 Please create an issue on the project's GitHub page to request support for this format.
 
-Supported formats: JSON, XML, HTML, Plain Text`)
+Supported formats: JSON, XML, HTML, Plain Text
+`)
 			}
 		}
-	}
+	}, func() { stopOnce.Do(func() { close(stopCh) }) }
 }
 
 var (

internal/http/handlers/error_page/handler_test.go

@@ -48,7 +48,7 @@ func TestHandler(t *testing.T) {
 			wantStatusCode: http.StatusOK,
 			wantHeaders:    map[string]string{"Content-Type": "text/html; charset=utf-8"},
 			wantBodyIncludes: []string{
-				"<!DOCTYPE html>",
+				"<!doctype html>",
 				"<title>407: Proxy Authentication Required",
 				"Proxy Authentication Required",
 			},
@@ -159,7 +159,8 @@ func TestHandler(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 
-			var handler = error_page.New(tt.giveConfig(), logger.NewNop())
+			var handler, closeCache = error_page.New(tt.giveConfig(), logger.NewNop())
+			defer closeCache()
 
 			req, reqErr := http.NewRequest(http.MethodGet, tt.giveUrl, http.NoBody)
 			require.NoError(t, reqErr)
@@ -202,9 +203,11 @@ func TestRotationModeOnEachRequest(t *testing.T) {
 		lastResponseBody string
 		changedTimes     int
 
-		handler = error_page.New(&cfg, logger.NewNop())
+		handler, closeCache = error_page.New(&cfg, logger.NewNop())
 	)
 
+	defer func() { closeCache(); closeCache(); closeCache() }() // multiple calls should not panic
+
 	for range 300 {
 		req, reqErr := http.NewRequest(http.MethodGet, "http://testing/", http.NoBody)
 		require.NoError(t, reqErr)

internal/http/server.go

@@ -23,16 +23,16 @@ import (
 
 // Server is an HTTP server for serving error pages.
 type Server struct {
-	log    *logger.Logger
-	server *fasthttp.Server
+	log        *logger.Logger
+	server     *fasthttp.Server
+	beforeStop func()
 }
 
 // NewServer creates a new HTTP server.
-func NewServer(log *logger.Logger) Server {
+func NewServer(log *logger.Logger, readBufferSize uint) Server {
 	const (
-		readTimeout    = 30 * time.Second
-		writeTimeout   = readTimeout + 10*time.Second // should be bigger than the read timeout
-		maxHeaderBytes = (1 << 20) * 5                //nolint:mnd // 5 MB
+		readTimeout  = 30 * time.Second
+		writeTimeout = readTimeout + 10*time.Second // should be bigger than the read timeout
 	)
 
 	return Server{
@@ -40,33 +40,38 @@ func NewServer(log *logger.Logger) Server {
 		server: &fasthttp.Server{
 			ReadTimeout:                  readTimeout,
 			WriteTimeout:                 writeTimeout,
-			ReadBufferSize:               maxHeaderBytes,
+			ReadBufferSize:               int(readBufferSize),
 			DisablePreParseMultipartForm: true,
 			NoDefaultServerHeader:        true,
 			CloseOnShutdown:              true,
 			Logger:                       logger.NewStdLog(log),
 		},
+		beforeStop: func() {}, // noop
 	}
 }
 
 // Register server handlers, middlewares, etc.
-func (s *Server) Register(cfg *config.Config) error {
+func (s *Server) Register(cfg *config.Config) error { //nolint:funlen
 	var (
-		liveHandler       = live.New()
-		versionHandler    = version.New(appmeta.Version())
-		errorPagesHandler = ep.New(cfg, s.log)
-		faviconHandler    = static.New(static.Favicon)
+		liveHandler    = live.New()
+		versionHandler = version.New(appmeta.Version())
+		faviconHandler = static.New(static.Favicon)
+
+		errorPagesHandler, closeCache = ep.New(cfg, s.log)
 
 		notFound   = http.StatusText(http.StatusNotFound) + "\n"
 		notAllowed = http.StatusText(http.StatusMethodNotAllowed) + "\n"
 	)
 
+	// wrap the before shutdown function to close the cache
+	s.beforeStop = closeCache
+
 	s.server.Handler = func(ctx *fasthttp.RequestCtx) {
 		var url, method = string(ctx.Path()), string(ctx.Method())
 
 		switch {
 		// live endpoints
-		case url == "/health/live" || url == "/health" || url == "/healthz" || url == "/live":
+		case url == "/healthz" || url == "/health/live" || url == "/health" || url == "/live":
 			liveHandler(ctx)
 
 		// version endpoint
@@ -82,8 +87,9 @@ func (s *Server) Register(cfg *config.Config) error {
 		//	-	/{code}.html
 		//	- /{code}.htm
 		//	- /{code}
-		case method == fasthttp.MethodGet &&
-			(url == "/" || ep.URLContainsCode(url) || ep.HeadersContainCode(&ctx.Request.Header)):
+		//
+		// the HTTP method is not limited to GET and HEAD - it can be any
+		case url == "/" || ep.URLContainsCode(url) || ep.HeadersContainCode(&ctx.Request.Header):
 			errorPagesHandler(ctx)
 
 		// wrong requests handling
@@ -135,5 +141,7 @@ func (s *Server) Stop(timeout time.Duration) error {
 	var ctx, cancel = context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 
+	s.beforeStop()
+
 	return s.server.ShutdownWithContext(ctx)
 }

internal/http/server_test.go

@@ -20,7 +20,7 @@ import (
 // TestRouting in fact is a test for the whole server, because it tests all the routes and their handlers.
 func TestRouting(t *testing.T) {
 	var (
-		srv = appHttp.NewServer(logger.NewNop())
+		srv = appHttp.NewServer(logger.NewNop(), 1025*5)
 		cfg = config.New()
 	)
 
@@ -38,7 +38,7 @@ func TestRouting(t *testing.T) {
 		Service Name: {{ service_name }}
 		Service Port: {{ service_port }}
 		Request ID: {{ request_id }}
-		Timestamp: {{ now.Unix }}
+		Timestamp: {{ nowUnix }}
 	</pre>{{ end }}
 </html>`))
 
@@ -221,6 +221,16 @@ func TestRouting(t *testing.T) {
 				assert.Contains(t, string(body), "404: Not Found")
 				assert.Contains(t, headers.Get("Content-Type"), "text/plain")
 			})
+
+			t.Run("other HTTP methods", func(t *testing.T) {
+				for _, method := range []string{http.MethodDelete, http.MethodPatch, http.MethodPost, http.MethodPut} {
+					var status, body, headers = sendRequest(t, method, baseUrl+"/404.html")
+
+					assert.Equal(t, http.StatusOK, status)
+					assert.Contains(t, string(body), "404: Not Found")
+					assert.Contains(t, headers.Get("Content-Type"), "text/plain")
+				}
+			})
 		})
 
 		t.Run("failure", func(t *testing.T) {
@@ -264,15 +274,6 @@ func TestRouting(t *testing.T) {
 				assert.Equal(t, http.StatusNotFound, status)
 				assertIsNotErrorPage(t, body)
 			})
-
-			t.Run("invalid HTTP methods", func(t *testing.T) {
-				for _, method := range []string{http.MethodDelete, http.MethodPatch, http.MethodPost, http.MethodPut} {
-					var status, body, _ = sendRequest(t, method, baseUrl+"/404.html")
-
-					assert.Equal(t, http.StatusMethodNotAllowed, status)
-					assertIsNotErrorPage(t, body)
-				}
-			})
 		})
 	})
 

internal/template/minify.go

@@ -0,0 +1,23 @@
+package template
+
+import (
+	"github.com/tdewolff/minify/v2"
+	"github.com/tdewolff/minify/v2/css"
+	"github.com/tdewolff/minify/v2/html"
+	"github.com/tdewolff/minify/v2/js"
+	"github.com/tdewolff/minify/v2/svg"
+)
+
+var htmlMinify = func() *minify.M { //nolint:gochecknoglobals
+	var m = minify.New()
+
+	m.AddFunc("text/css", css.Minify)
+	m.Add("text/html", &html.Minifier{KeepDocumentTags: true, KeepEndTags: true, KeepQuotes: true})
+	m.AddFunc("image/svg+xml", svg.Minify)
+	m.AddFunc("application/javascript", js.Minify)
+
+	return m
+}()
+
+// MiniHTML minifies HTML data, including inline CSS, SVG and JS.
+func MiniHTML(data string) (string, error) { return htmlMinify.String("text/html", data) }

internal/template/minify_test.go

@@ -0,0 +1,94 @@
+package template_test
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"gh.tarampamp.am/error-pages/internal/template"
+)
+
+func TestMiniHTML(t *testing.T) {
+	t.Parallel()
+
+	var wg sync.WaitGroup
+
+	for range 100 { // race condition provocation
+		wg.Add(1)
+
+		go func() {
+			defer wg.Done()
+
+			for give, want := range map[string]string{
+				"": "",
+				`<!-- Simple HTML page -->
+<!DOCTYPE html>
+<html>
+<head>
+	<title>Test</title>
+</head>
+<body>
+	<h1 align="center">Test</h1>
+</body>
+</html>`: `<!doctype html><html><head><title>Test</title></head><body><h1 align="center">Test</h1></body></html>`,
+				`<!-- css styles -->
+<html>
+<head>
+	<style>
+		.foo:hover {
+			color: #f0a; /* comment */
+		}
+	</style>
+</head>
+<body>
+	<p style="color: red" class="bar">Text</p>
+</body>
+</html>`: `<html><head><style>.foo:hover{color:#f0a}</style></head><body><p style="color:red" class="bar">Text</p></body></html>`,
+				`<!-- svg -->
+<svg xmlns="http://www.w3.org/2000/svg">
+	<g>
+		<circle cx="50" cy="50" r="40" stroke="black" stroke-width="3" fill="red" />
+	</g>
+</svg>`: `<svg><g><circle cx="50" cy="50" r="40" stroke="#000" stroke-width="3" fill="red"/></g></svg>`,
+				`<!-- js -->
+<html>
+<body>
+<script>
+	// comment
+	console.log('Hello, World!');
+
+	let foo = 1;
+	foo++;
+</script>
+</body>
+</html>`: `<html><body><script>console.log("Hello, World!");let foo=1;foo++</script></body></html>`,
+				`<!-- js module not changed -->
+<html>
+<body>
+<script type="module">
+	// comment
+	console.log('Hello, World!');
+
+	let foo = 1;
+	foo++;
+</script>
+</body>
+</html>`: `<html><body><script type="module">
+	// comment
+	console.log('Hello, World!');
+
+	let foo = 1;
+	foo++;
+</script></body></html>`,
+			} {
+				var got, err = template.MiniHTML(give)
+
+				assert.NoError(t, err)
+				assert.Equal(t, want, got)
+			}
+		}()
+	}
+
+	wg.Wait()
+}

internal/template/template.go

@@ -16,10 +16,9 @@ import (
 )
 
 var builtInFunctions = template.FuncMap{ //nolint:gochecknoglobals
-	// current time:
-	//	`{{ now.Unix }}`	// `1631610000`
-	//	`{{ now.Hour }}:{{ now.Minute }}:{{ now.Second }}`	// `15:4:5`
-	"now": time.Now,
+	// the current time in unix format (seconds since 1970 UTC):
+	//	`{{ nowUnix }}`	// `1631610000`
+	"nowUnix": func() int64 { return time.Now().Unix() },
 
 	// current hostname:
 	//	`{{ hostname }}`	// `localhost`

internal/template/template_test.go

@@ -27,7 +27,7 @@ func TestRender_BuiltInFunction(t *testing.T) {
 		wantErrMsg   string
 	}{
 		"now (unix)": {
-			giveTemplate: `{{ now.Unix }}`,
+			giveTemplate: `{{ nowUnix }}`,
 			wantResult:   strconv.Itoa(int(time.Now().Unix())),
 		},
 		"hostname":                  {giveTemplate: `{{ hostname }}`, wantResult: hostname},

l10n/l10n.js

@@ -16,7 +16,7 @@ Object.defineProperty(window, 'l10n', {
      *
      * @link https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes language codes list (column `Set 1` or `ISO 639-1:2002`)
      *
-     * @type {Map<string, Map<'fr'|'ru'|'uk'|'pt'|'nl'|'de'|'es'|'zh'|'id'|'pl', string>>}
+     * @type {Map<string, Map<'fr'|'ru'|'uk'|'pt'|'nl'|'de'|'es'|'zh'|'id'|'pl'|'ko', string>>}
      */
     const data = Object.freeze(new Map([
       [tkn('Error'), new Map([
@@ -30,6 +30,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '错误'],
         ['id', 'Kesalahan'],
         ['pl', 'Błąd'],
+        ['ko', '오류'],
       ])],
       [tkn('Good luck'), new Map([
         ['fr', 'Bonne chance'],
@@ -42,6 +43,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '祝好运'],
         ['id', 'Semoga berhasil!'],
         ['pl', 'Powodzenia'],
+        ['ko', '행운을 빌어요'],
       ])],
       [tkn('UH OH'), new Map([
         ['fr', 'Oups'],
@@ -54,6 +56,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '哎呀'],
         ['id', 'Ups'],
         ['pl', 'Ojej'],
+        ['ko', '헉'],
       ])],
       [tkn('Request details'), new Map([
         ['fr', 'Détails de la requête'],
@@ -66,6 +69,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求详情'],
         ['id', 'Rincian permintaan'],
         ['pl', 'Poproś o szczegóły'],
+        ['ko', '요청 세부사항'],
       ])],
       [tkn('Double-check the URL'), new Map([
         ['fr', 'Vérifiez l’URL'],
@@ -78,6 +82,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请再次检查地址'],
         ['id', 'Periksa URL'],
         ['pl', 'Sprawdź adres URL'],
+        ['ko', 'URL을 다시 확인하세요'],
       ])],
       [tkn('Alternatively, go back'), new Map([
         ['fr', 'Essayer de revenir en arrière'],
@@ -90,6 +95,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '或返回上一页'],
         ['id', 'Atau, kembali'],
         ['pl', 'Alternatywnie wróć'],
+        ['ko', '혹은, 돌아가기'],
       ])],
       [tkn("Here's what might have happened"), new Map([
         ['fr', 'Voici ce qui aurait pu se passer'],
@@ -102,6 +108,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '可能原因有'],
         ['id', 'Inilah yang bisa saja terjadi'],
         ['pl', 'Oto, co mogło się wydarzyć'],
+        ['ko', '다음이 발생했을 수 있어요'],
       ])],
       [tkn('You may have mistyped the URL'), new Map([
         ['fr', 'Vous avez peut-être mal tapé l’URL'],
@@ -114,6 +121,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '您可能输入了错误的地址'],
         ['id', 'Anda mungkin tersalah memasukkan URL'],
         ['pl', 'Być może błędnie wpisałeś adres URL'],
+        ['ko', 'URL을 잘못 입력하셨을 수 있어요'],
       ])],
       [tkn('The site was moved'), new Map([
         ['fr', 'Le site a été déplacé'],
@@ -126,6 +134,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '站点已被转移'],
         ['id', 'Halaman dipindahkan'],
         ['pl', 'Witryna została przeniesiona'],
+        ['ko', '사이트가 이동했어요'],
       ])],
       [tkn('It was never here'), new Map([
         ['fr', 'Il n’a jamais été ici'],
@@ -138,6 +147,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '站点从未存在'],
         ['id', 'Itu Tidak pernah di sini'],
         ['pl', 'Nigdy jej nie było'],
+        ['ko', '여기에 있던 적이 없어요'],
       ])],
       [tkn('Bad Request'), new Map([
         ['fr', 'Mauvaise requête'],
@@ -150,6 +160,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '错误请求'],
         ['id', 'Permintaan yang salah'],
         ['pl', 'Nieprawidłowe żądanie'],
+        ['ko', '잘못된 요청'],
       ])],
       [tkn('The server did not understand the request'), new Map([
         ['fr', 'Le serveur ne comprend pas la requête'],
@@ -162,6 +173,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器不理解该请求'],
         ['id', 'Server tidak memahami permintaan'],
         ['pl', 'Serwer nie zrozumiał żądania'],
+        ['ko', '서버가 요청을 이해하지 못했어요'],
       ])],
       [tkn('Unauthorized'), new Map([
         ['fr', 'Non autorisé'],
@@ -174,6 +186,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '未经授权'],
         ['id', 'Tidak diotorisasi'],
         ['pl', 'Nieautoryzowany'],
+        ['ko', '권한 없음'],
       ])],
       [tkn('The requested page needs a username and a password'), new Map([
         ['fr', 'La page demandée nécessite un nom d’utilisateur et un mot de passe'],
@@ -186,6 +199,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求的页面需要用户名和密码'],
         ['id', 'Halaman yang diminta membutuhkan nama pengguna dan kata sandi'],
         ['pl', 'Żądana strona wymaga podania nazwy użytkownika i hasła'],
+        ['ko', '요청하신 페이지에는 사용자 이름과 비밀번호가 필요해요'],
       ])],
       [tkn('Forbidden'), new Map([
         ['fr', 'Interdit'],
@@ -198,6 +212,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '禁止访问'],
         ['id', 'Dilarang'],
         ['pl', 'Zabroniony'],
+        ['ko', '금지됨'],
       ])],
       [tkn('Access is forbidden to the requested page'), new Map([
         ['fr', 'Accès interdit à la page demandée'],
@@ -210,6 +225,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '禁止访问请求的页面'],
         ['id', 'Akses dilarang ke halaman yang diminta'],
         ['pl', 'Dostęp do żądanej strony jest zabroniony'],
+        ['ko', '요청하신 페이지에 대한 접근이 금지되어 있어요'],
       ])],
       [tkn('Not Found'), new Map([
         ['fr', 'Introuvable'],
@@ -222,6 +238,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '未找到'],
         ['id', 'Tidak ditemukan'],
         ['pl', 'Nie znaleziono'],
+        ['ko', '찾을 수 없음'],
       ])],
       [tkn('The server can not find the requested page'), new Map([
         ['fr', 'Le serveur ne peut trouver la page demandée'],
@@ -234,6 +251,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器找不到请求的页面'],
         ['id', 'Server tidak dapat menemukan halaman yang diminta'],
         ['pl', 'Serwer nie może znaleźć żądanej strony'],
+        ['ko', '서버가 요청한 페이지를 찾을 수 없어요'],
       ])],
       [tkn('Method Not Allowed'), new Map([
         ['fr', 'Méthode Non Autorisée'],
@@ -246,6 +264,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '方法不被允许'],
         ['id', 'Metode tidak diizinkan'],
         ['pl', 'Niedozwolona metoda'],
+        ['ko', '허용되지 않은 메소드'],
       ])],
       [tkn('The method specified in the request is not allowed'), new Map([
         ['fr', 'La méthode spécifiée dans la requête n’est pas autorisée'],
@@ -258,6 +277,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求指定的方法不被允许'],
         ['id', 'Metode dalam permintaan tidak diizinkan'],
         ['pl', 'Metoda określona w żądaniu jest niedozwolona'],
+        ['ko', '요청에 사용한 메소드는 허용되지 않아요'],
       ])],
       [tkn('Proxy Authentication Required'), new Map([
         ['fr', 'Authentification proxy requise'],
@@ -270,6 +290,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '需要代理服务器身份验证'],
         ['id', 'Diperlukan otentikasi proxy'],
         ['pl', 'Wymagane uwierzytelnianie proxy'],
+        ['ko', '프록시 인증 필요'],
       ])],
       [tkn('You must authenticate with a proxy server before this request can be served'), new Map([
         ['fr', 'Vous devez vous authentifier avec un serveur proxy avant que cette requête puisse être servie'],
@@ -282,6 +303,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '您必须对代理服务器进行身份验证，然后才能让请求得到处理'],
         ['id', 'Anda harus mengautentikasi dengan server proxy sebelum permintaan ini dapat dilayani'],
         ['pl', 'Musisz uwierzytelnić się na serwerze proxy, zanim to żądanie będzie mogło zostać obsłużone'],
+        ['ko', '이 요청을 처리하려면 프록시 서버로 인증해야 해요'],
       ])],
       [tkn('Request Timeout'), new Map([
         ['fr', 'Requête expiré'],
@@ -294,6 +316,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求超时'],
         ['id', 'Meminta batas waktu'],
         ['pl', 'Przekroczenie limitu czasu żądania'],
+        ['ko', '요청 시간초과'],
       ])],
       [tkn('The request took longer than the server was prepared to wait'), new Map([
         ['fr', 'La requête prend plus de temps que prévu'],
@@ -306,6 +329,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求用时超过了服务器设置的最长等待时间'],
         ['id', 'Permintaan memakan waktu lebih lama dari yang bisa ditunggu oleh server'],
         ['pl', 'Żądanie trwało dłużej niż serwer był gotowy czekać'],
+        ['ko', '요청이 서버가 기다릴 수 있는 시간보다 오래 걸렸어요'],
       ])],
       [tkn('Conflict'), new Map([
         ['fr', 'Conflit'],
@@ -318,6 +342,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '冲突'],
         ['id', 'Konflik'],
         ['pl', 'Konflikt'],
+        ['ko', '상충'],
       ])],
       [tkn('The request could not be completed because of a conflict'), new Map([
         ['fr', 'La requête n’a pas pu être complétée à cause d’un conflit'],
@@ -330,6 +355,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '由于冲突，请求无法完成'],
         ['id', 'Permintaan tidak dapat diselesaikan karena adanya konflik'],
         ['pl', 'Żądanie nie mogło zostać wykonane z powodu konfliktu'],
+        ['ko', '상충으로 인해 요청을 완료할 수 없었어요'],
       ])],
       [tkn('Gone'), new Map([
         ['fr', 'Supprimé'],
@@ -342,6 +368,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '已移除'],
         ['id', 'Menghilang'],
         ['pl', 'Usunięto'],
+        ['ko', '사라짐'],
       ])],
       [tkn('The requested page is no longer available'), new Map([
         ['fr', 'La page demandée n’est plus disponible'],
@@ -354,6 +381,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求的页面不再可用'],
         ['id', 'Halaman yang diminta tidak lagi tersedia'],
         ['pl', 'Żądana strona nie jest już dostępna'],
+        ['ko', '요청하신 페이지는 더 이상 사용할 수 없어요'],
       ])],
       [tkn('Length Required'), new Map([
         ['fr', 'Longueur requise'],
@@ -366,6 +394,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '需要长度'],
         ['id', 'Panjang yang diperlukan'],
         ['pl', 'Wymagana długość'],
+        ['ko', '길이 필요'],
       ])],
       [tkn('The "Content-Length" is not defined. The server will not accept the request without it'), new Map([
         ['fr', 'Le "Content-Length" n’est pas défini. Le serveur ne prendra pas en compte la requête'],
@@ -378,6 +407,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '未指定Content-Length(内容长度)。服务器将不接受不包含此头信息的请求'],
         ['id', '"Content-Length" tidak ditentukan. Server tidak akan menerima permintaan tanpa itu'],
         ['pl', 'Wartość "Content-Length" nie jest zdefiniowana. Serwer nie zaakceptuje żądania bez tego parametru'],
+        ['ko', '"Content-Length"가 정의되지 않았습니다. 이 값이 없으면 서버는 요청을 수락하지 않아요'],
       ])],
       [tkn('Precondition Failed'), new Map([
         ['fr', 'Échec de la condition préalable'],
@@ -390,6 +420,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '前置条件判定失败'],
         ['id', 'Prasyarat gagal'],
         ['pl', 'Niespełnienie warunku wstępnego'],
+        ['ko', '선결 조건 실패'],
       ])],
       [tkn('The pre condition given in the request evaluated to false by the server'), new Map([
         ['fr', 'La précondition donnée dans la requête a été évaluée comme étant fausse par le serveur'],
@@ -402,6 +433,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器评估请求中给出的前置条件的结果为false(假)'],
         ['id', 'Prakondisi gagal'],
         ['pl', 'Warunek wstępny podany w żądaniu został oceniony przez serwer jako nieprawidłowy'],
+        ['ko', '요청에 제공된 선결 조건을 서버는 거짓으로 평가했어요'],
       ])],
       [tkn('Payload Too Large'), new Map([
         ['fr', 'Charge trop volumineuse'],
@@ -414,6 +446,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求体过大'],
         ['id', 'Muatan terlalu besar'],
         ['pl', 'Żądanie jest zbyt duże'],
+        ['ko', '콘텐츠가 너무 큼'],
       ])],
       [tkn('The server will not accept the request, because the request entity is too large'), new Map([
         ['fr', 'Le serveur ne prendra pas en compte la requête, car l’entité de la requête est trop volumineuse'],
@@ -426,6 +459,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求体过大，服务器将不接受该请求'],
         ['id', 'Server tidak akan menerima permintaan, karena entitas permintaan terlalu besar'],
         ['pl', 'Serwer nie zaakceptuje żądania, ponieważ żądanie jest zbyt duże'],
+        ['ko', '요청 엔터티가 너무 크기 때문에 서버가 요청을 수락하지 않았어요'],
       ])],
       [tkn('Requested Range Not Satisfiable'), new Map([
         ['fr', 'Requête non satisfaisante'],
@@ -438,6 +472,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '不满足请求范围'],
         ['id', 'Rentang yang diminta tidak dapat dipenuhi'],
         ['pl', 'Żądany zakres nie jest satysfakcjonujący'],
+        ['ko', '처리할 수 없는 요청 범위'],
       ])],
       [tkn('The requested byte range is not available and is out of bounds'), new Map([
         ['fr', 'Le byte range demandé n’est pas disponible et est hors des limites'],
@@ -450,6 +485,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求的字节范围不可用，超出边界'],
         ['id', 'Rentang byte yang diminta tidak tersedia dan di luar batas'],
         ['pl', 'Żądany zakres bajtów nie jest dostępny i znajduje się poza zakresem'],
+        ['ko', '요청한 범위를 사용할 수 없고, 범위를 벗어났어요'],
       ])],
       [tkn("I'm a teapot"), new Map([
         ['fr', 'Je suis une théière'],
@@ -462,6 +498,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '我是一只茶壶'],
         ['id', 'Saya adalah teko'],
         ['pl', 'Jestem czajniczkiem'],
+        ['ko', '저는 찻주전자에요'],
       ])],
       [tkn('Attempt to brew coffee with a teapot is not supported'), new Map([
         ['fr', 'Tenter de préparer du café avec une théière n’est pas pris en charge'],
@@ -474,6 +511,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '用茶壶泡咖啡不受支持'],
         ['id', 'Upaya menyeduh kopi dengan teko tidak didukung'],
         ['pl', 'Próba zaparzenia kawy za pomocą czajniczka nie jest obsługiwana'],
+        ['ko', '찻주전자로 커피를 내리는 시도는 지원되지 않아요'],
       ])],
       [tkn('Too Many Requests'), new Map([
         ['fr', 'Trop de requêtes'],
@@ -486,6 +524,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求过多'],
         ['id', 'Terlalu banyak permintaan'],
         ['pl', 'Zbyt wiele żądań'],
+        ['ko', '요청이 너무 많음'],
       ])],
       [tkn('Too many requests in a given amount of time'), new Map([
         ['fr', 'Trop de requêtes dans un délai donné'],
@@ -498,6 +537,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '在给定的时间内发送了过多请求'],
         ['id', 'Terlalu banyak permintaan dalam waktu tertentu'],
         ['pl', 'Zbyt wiele żądań w określonym czasie'],
+        ['ko', '지정된 시간 내에 요청이 너무 많아요'],
       ])],
       [tkn('Internal Server Error'), new Map([
         ['fr', 'Erreur interne du serveur'],
@@ -510,6 +550,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '内部服务器错误'],
         ['id', 'Kesalahan server internal'],
         ['pl', 'Wewnętrzny błąd serwera'],
+        ['ko', '내부 서버 오류'],
       ])],
       [tkn('The server met an unexpected condition'), new Map([
         ['fr', 'Le serveur a rencontré une condition inattendue'],
@@ -522,6 +563,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器遇到了意外情况'],
         ['id', 'Server mengalami kondisi yang tidak terduga'],
         ['pl', 'Serwer napotkał nieoczekiwany stan'],
+        ['ko', '서버가 예상치 못한 조건이에요'],
       ])],
       [tkn('Bad Gateway'), new Map([
         ['fr', 'Mauvaise passerelle'],
@@ -534,6 +576,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '无效网关'],
         ['id', 'Gateway yang buruk'],
         ['pl', 'Błąd bramki'],
+        ['ko', '게이트웨이 불량'],
       ])],
       [tkn('The server received an invalid response from the upstream server'), new Map([
         ['fr', 'Le serveur a reçu une réponse invalide du serveur distant'],
@@ -546,6 +589,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器从上游服务器收到了无效的响应'],
         ['id', 'Server menerima respons yang tidak valid dari server induk'],
         ['pl', 'Serwer otrzymał nieprawidłową odpowiedź od serwera nadrzędnego'],
+        ['ko', '게이트웨이가 업스트림 서버로부터 잘못된 응답을 받았어요'],
       ])],
       [tkn('Service Unavailable'), new Map([
         ['fr', 'Service indisponible'],
@@ -558,6 +602,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务不可用'],
         ['id', 'Layanan tidak tersedia'],
         ['pl', 'Serwis niedostępny'],
+        ['ko', '서비스 불가능'],
       ])],
       [tkn('The server is temporarily overloading or down'), new Map([
         ['fr', 'Le serveur est temporairement en surcharge ou indisponible'],
@@ -570,6 +615,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器暂时过载或不可用'],
         ['id', 'Server untuk sementara kelebihan beban atau tidak tersedia'],
         ['pl', 'Serwer jest tymczasowo przeciążony lub wyłączony'],
+        ['ko', '서버가 일시적으로 과부하 상태이거나 다운되었어요'],
       ])],
       [tkn('Gateway Timeout'), new Map([
         ['fr', 'Expiration Passerelle'],
@@ -582,6 +628,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '网关超时'],
         ['id', 'Batas waktu gateway'],
         ['pl', 'Przekroczenie limitu czasu bramki'],
+        ['ko', '게이트웨이 시간초과'],
       ])],
       [tkn('The gateway has timed out'), new Map([
         ['fr', 'Le temps d’attente de la passerelle est dépassé'],
@@ -594,6 +641,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '网关响应已经超时'],
         ['id', 'Sambungan ke server induk telah kedaluwarsa'],
         ['pl', 'Bramka przekroczyła limit czasu'],
+        ['ko', '게이트웨이 시간이 초과되었어요'],
       ])],
       [tkn('HTTP Version Not Supported'), new Map([
         ['fr', 'Version HTTP non prise en charge'],
@@ -606,6 +654,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', 'HTTP版本不受支持'],
         ['id', 'Versi HTTP tidak didukung'],
         ['pl', 'Wersja HTTP nie jest obsługiwana'],
+        ['ko', '지원하지 않는 HTTP 버전'],
       ])],
       [tkn('The server does not support the "http protocol" version'), new Map([
         ['fr', 'Le serveur ne supporte pas la version du protocole HTTP'],
@@ -618,6 +667,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务器不支持该HTTP协议版本'],
         ['id', 'Server tidak mendukung versi HTTP ini'],
         ['pl', 'Serwer nie obsługuje wersji "protokołu http"'],
+        ['ko', '서버가 해당 "HTTP 프로토콜"을 지원하지 않아요'],
       ])],
       [tkn('Host'), new Map([
         ['fr', 'Hôte'],
@@ -630,6 +680,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '主机'],
         ['id', 'Host'],
         ['pl', 'Host'],
+        ['ko', '호스트'],
       ])],
       [tkn('Original URI'), new Map([
         ['fr', 'URI d’origine'],
@@ -642,6 +693,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '原始URI'],
         ['id', 'URL asli'],
         ['pl', 'Oryginalny URI'],
+        ['ko', '원시 URI'],
       ])],
       [tkn('Forwarded for'), new Map([
         ['fr', 'Transmis pour'],
@@ -654,6 +706,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '转发自'],
         ['id', 'Diteruskan untuk'],
         ['pl', 'Przekazane do'],
+        ['ko', '전달받은 대상'],
       ])],
       [tkn('Namespace'), new Map([
         ['fr', 'Espace de noms'],
@@ -666,6 +719,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '命名空间'],
         ['id', 'Ruang nama'],
         ['pl', 'Przestrzeń nazw'],
+        ['ko', '네임스페이스'],
       ])],
       [tkn('Ingress name'), new Map([
         ['fr', 'Nom ingress'],
@@ -678,6 +732,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '入口名'],
         ['id', 'Nama ingress'],
         ['pl', 'Nazwa wejścia'],
+        ['ko', '인그레스 이름'],
       ])],
       [tkn('Service name'), new Map([
         ['fr', 'Nom du service'],
@@ -690,6 +745,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务名'],
         ['id', 'Nama layanan'],
         ['pl', 'Nazwa usługi'],
+        ['ko', '서비스 이름'],
       ])],
       [tkn('Service port'), new Map([
         ['fr', 'Port du service'],
@@ -702,6 +758,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务端口'],
         ['id', 'Port layanan'],
         ['pl', 'Port usługi'],
+        ['ko', '서비스 포트'],
       ])],
       [tkn('Request ID'), new Map([
         ['fr', 'Identifiant de la requête'],
@@ -714,6 +771,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请求ID'],
         ['id', 'ID permintaan'],
         ['pl', 'Identyfikator żądania'],
+        ['ko', '요청 ID'],
       ])],
       [tkn('Timestamp'), new Map([
         ['fr', 'Horodatage'],
@@ -726,6 +784,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '时间戳'],
         ['id', 'Cap waktu'],
         ['pl', 'Sygnatura czasowa'],
+        ['ko', '시간 기록'],
       ])],
       [tkn('client-side error'), new Map([
         ['fr', 'Erreur Client'],
@@ -738,6 +797,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '客户端错误'],
         ['id', 'Kesalahan sisi klien'],
         ['pl', 'błąd po stronie klienta'],
+        ['ko', '클라이언트 측 오류'],
       ])],
       [tkn('server-side error'), new Map([
         ['fr', 'Erreur Serveur'],
@@ -750,6 +810,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '服务端错误'],
         ['id', 'Kesalahan sisi server'],
         ['pl', 'błąd po stronie serwera'],
+        ['ko', '서버 측 오류'],
       ])],
       [tkn('Your Client'), new Map([
         ['fr', 'Votre Client'],
@@ -762,6 +823,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '您的客户端'],
         ['id', 'Klien Anda'],
         ['pl', 'Klient'],
+        ['ko', '내 클라이언트'],
       ])],
       [tkn('Network'), new Map([
         ['fr', 'Réseau'],
@@ -774,6 +836,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '网络'],
         ['id', 'Jaringan'],
         ['pl', 'Sieć'],
+        ['ko', '네트워크'],
       ])],
       [tkn('Web Server'), new Map([
         ['fr', 'Serveur Web'],
@@ -786,6 +849,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', 'Web服务器'],
         ['id', 'Server web'],
         ['pl', 'Serwer WWW'],
+        ['ko', '웹 서버'],
       ])],
       [tkn('What happened?'), new Map([
         ['fr', 'Que s’est-il passé ?'],
@@ -798,6 +862,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '发生了什么？'],
         ['id', 'Apa yang terjadi?'],
         ['pl', 'Co się stało?'],
+        ['ko', '어떤 일이 일어났나요?'],
       ])],
       [tkn('What can I do?'), new Map([
         ['fr', 'Que puis-je faire ?'],
@@ -810,6 +875,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '我能做什么？'],
         ['id', 'Apa yang bisa saya lakukan?'],
         ['pl', 'Co mogę zrobić?'],
+        ['ko', '어떤 것을 할 수 있나요?'],
       ])],
       [tkn('Please try again in a few minutes'), new Map([
         ['fr', 'Veuillez réessayer dans quelques minutes'],
@@ -822,6 +888,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请在几分钟后重试'],
         ['id', 'Silakan coba lagi dalam beberapa menit'],
         ['pl', 'Spróbuj ponownie za kilka minut'],
+        ['ko', '몇 분 후에 다시 시도해 주세요'],
       ])],
       [tkn('Working'), new Map([
         ['fr', 'Opérationnel'],
@@ -834,6 +901,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '正常运行'],
         ['id', 'Fungsi'],
         ['pl', 'Działa'],
+        ['ko', '작동 중'],
       ])],
       [tkn('Unknown'), new Map([
         ['fr', 'Inconnu'],
@@ -846,6 +914,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '未知'],
         ['id', 'Tidak diketahui'],
         ['pl', 'Nieznany'],
+        ['ko', '알 수 없음'],
       ])],
       [tkn('Please try to change the request method, headers, payload, or URL'), new Map([
         ['fr', 'Veuillez essayer de changer la méthode de requête, les en-têtes, le contenu ou l’URL'],
@@ -858,6 +927,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请尝试更改请求方法、标头、有效负载或URL'],
         ['id', 'Coba lagi dengan metode, header, muatan, atau URL yang berbeda'],
         ['pl', 'Spróbuj zmienić metodę żądania, nagłówki, żądanie lub adres URL'],
+        ['ko', '요청 방법, 헤더, 콘텐츠 또는 URL을 변경해 보세요'],
       ])],
       [tkn('Please check your authorization data'), new Map([
         ['fr', 'Veuillez vérifier vos données d’autorisation'],
@@ -870,6 +940,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请检查您的授权数据'],
         ['id', 'Memeriksa detail autentikasi'],
         ['pl', 'Sprawdź swoje dane autoryzacyjne'],
+        ['ko', '인증 데이터를 확인해주세요'],
       ])],
       [tkn('Please double-check the URL and try again'), new Map([
         ['fr', 'Veuillez vérifier l’URL et réessayer'],
@@ -882,6 +953,7 @@ Object.defineProperty(window, 'l10n', {
         ['zh', '请再次检查URL并重试'],
         ['id', 'Periksa URL dan coba lagi'],
         ['pl', 'Sprawdź adres URL i spróbuj ponownie'],
+        ['ko', 'URL을 다시 한번 확인해 주세요'],
       ])],
     ]));
 

l10n/playground.html

@@ -118,8 +118,8 @@
 
   const $langSwitch = document.getElementById('lang-switch');
 
-  ['fr', 'ru', 'uk', 'pt', 'nl', 'de', 'es', 'zh', 'id', 'pl'].forEach((lang) => {
-    //                                                     ^^^ add your newly added locale here
+  ['fr', 'ru', 'uk', 'pt', 'nl', 'de', 'es', 'zh', 'id', 'pl', 'ko' ].forEach((lang) => {
+    //                                                            ^^^ add your newly added locale here
     const $li = document.createElement('li');
     const $btn = document.createElement('button');
 

l10n/readme.md

@@ -28,3 +28,4 @@ different locales, please follow these steps:
 - 🇨🇳 Chinese by [@CDN18](https://github.com/CDN18)
 - 🇮🇩 Indonesian by [@getwisp](https://github.com/getwisp)
 - 🇵🇱 Polish by [@wielorzeczownik](https://github.com/wielorzeczownik)
+- 🇰🇷 Korean by [@NavyStack](https://github.com/NavyStack)

templates/app-down.html

@@ -341,7 +341,7 @@
         <!-- {{- end }}{{ if request_id -}} -->
         <li><span data-l10n>Request ID</span>: <code>{{ request_id }}</code></li>
         <!-- {{- end -}} -->
-        <li><span data-l10n>Timestamp</span>: <code>{{ now.Unix }}</code></li>
+        <li><span data-l10n>Timestamp</span>: <code>{{ nowUnix }}</code></li>
       </ul>
     </div>
     <!-- {{- end -}} -->

templates/cats.html

@@ -150,7 +150,7 @@
   <!-- {{- end -}} -->
   <tr>
     <td class="name" data-l10n>Timestamp</td>
-    <td class="value">{{ now.Unix }}</td>
+    <td class="value">{{ nowUnix }}</td>
   </tr>
   </tbody>
 </table>

templates/connection.html

@@ -327,7 +327,7 @@
       <!-- {{- end }}{{ if request_id -}} -->
       <li><span data-l10n>Request ID</span>: <code>{{ request_id }}</code></li>
       <!-- {{- end -}} -->
-      <li><span data-l10n>Timestamp</span>: <code>{{ now.Unix }}</code></li>
+      <li><span data-l10n>Timestamp</span>: <code>{{ nowUnix }}</code></li>
     </ul>
   </div>
   <!-- {{- end -}} -->

templates/ghost.html

@@ -235,7 +235,7 @@
     <!-- {{- end -}} -->
     <tr>
       <td class="name" data-l10n>Timestamp</td>
-      <td class="value">{{ now.Unix }}</td>
+      <td class="value">{{ nowUnix }}</td>
     </tr>
     </tbody>
   </table>

templates/hacker-terminal.html

@@ -174,7 +174,7 @@
     <!-- {{- end }}{{ if request_id -}} -->
     <p class="output small"><span data-l10n>Request ID</span>: <code>{{ request_id }}</code></p>
     <!-- {{- end -}} -->
-    <p class="output small"><span data-l10n>Timestamp</span>: <code>{{ now.Unix }}</code></p>
+    <p class="output small"><span data-l10n>Timestamp</span>: <code>{{ nowUnix }}</code></p>
   </div>
   <!-- {{- end -}} -->
 </main>

templates/l7.html

@@ -157,7 +157,7 @@
         <!-- {{- end }}{{ if request_id -}} -->
         <li class="value">{{ request_id }}</li>
         <!-- {{- end -}} -->
-        <li class="value">{{ now.Unix }}</li>
+        <li class="value">{{ nowUnix }}</li>
       </ul>
       <!-- {{- end -}} -->
     </div>

templates/lost-in-space.html

@@ -442,7 +442,7 @@
       <!-- {{- end }}{{ if request_id -}} -->
       <li><span data-l10n>Request ID</span>: <code>{{ request_id }}</code></li>
       <!-- {{- end -}} -->
-      <li><span data-l10n>Timestamp</span>: <code>{{ now.Unix }}</code></li>
+      <li><span data-l10n>Timestamp</span>: <code>{{ nowUnix }}</code></li>
     </ul>
     <!-- {{- end -}} -->
   </div>

templates/noise.html

@@ -9,7 +9,7 @@
     {{ if service_name }}Service name: {{ service_name }}{{ end }}
     {{ if service_port }}Service port: {{ service_port }}{{ end }}
     {{ if request_id }}Request ID: {{ request_id }}{{ end }}
-    Timestamp: {{ now.Unix }}
+    Timestamp: {{ nowUnix }}
 {{ end }}
 -->
 <html lang="en">

templates/orient.html

@@ -253,7 +253,7 @@
           <!-- {{- end -}} -->
           <tr>
             <td class="name" data-l10n>Timestamp</td>
-            <td class="value">{{ now.Unix }}</td>
+            <td class="value">{{ nowUnix }}</td>
           </tr>
         </table>
       </div>

templates/shuffle.html

@@ -167,7 +167,7 @@
       <!-- {{- end -}} -->
       <tr>
         <td class="name"><span data-l10n>Timestamp</span>:</td>
-        <td class="value">{{ now.Unix }}</td>
+        <td class="value">{{ nowUnix }}</td>
       </tr>
     </table>
     <!-- {{- end -}} -->