fix: "Too big request header" (#244)

* Added environment variable and CLI parameter for adjusting the read buffer size

* Changed readBufferSize to int and some bugfixing

* Small fixes

* ci: 👷 CI system updated

* ci: 👷 CI system updated

---------

Co-authored-by: Paramtamtam <7326800+tarampampam@users.noreply.github.com>

.github/workflows/tests.yml

@@ -30,7 +30,7 @@ jobs: # Docs: <https://git.io/JvxXE>
       - uses: actions/checkout@v4
 
       - uses: gacts/setup-go-with-cache@v1
-        with: {go-version: 1.19}
+        with: {go-version-file: go.mod}
 
       - uses: golangci/golangci-lint-action@v3
         with: {skip-pkg-cache: true, skip-build-cache: true}

CHANGELOG.md

@@ -9,8 +9,11 @@ The format is based on [Keep a Changelog][keepachangelog] and this project adher
 ### Added
 
 - Error pages now translated into 🇵🇱 [#226]
+- Possibility to set custom read buffer size (using `--read-buffer-size` flag or environment variable `READ_BUFFER_SIZE`) [#238], [#244]
 
 [#226]:https://github.com/tarampampam/error-pages/pull/226
+[#238]:https://github.com/tarampampam/error-pages/issues/238
+[#244]:https://github.com/tarampampam/error-pages/pull/244
 
 ## v2.25.0
 

Dockerfile

@@ -79,7 +79,8 @@ ENV LISTEN_PORT="8080" \
     DEFAULT_ERROR_PAGE="404" \
     DEFAULT_HTTP_CODE="404" \
     SHOW_DETAILS="false" \
-    DISABLE_L10N="false"
+    DISABLE_L10N="false" \
+    READ_BUFFER_SIZE="2048"
 
 # Docs: <https://docs.docker.com/engine/reference/builder/#healthcheck>
 HEALTHCHECK --interval=7s --timeout=2s CMD ["/bin/error-pages", "--log-json", "healthcheck"]

internal/cli/serve/command.go

@@ -33,6 +33,7 @@ const (
 	proxyHTTPHeadersFlagName = "proxy-headers"
 	disableL10nFlagName      = "disable-l10n"
 	catchAllFlagName         = "catch-all"
+	readBufferSizeFlagName   = "read-buffer-size"
 )
 
 const (
@@ -107,7 +108,7 @@ func NewCommand(log *zap.Logger) *cli.Command { //nolint:funlen
 				return fmt.Errorf("wrong default HTTP response code [%d]", o.Default.HTTPCode)
 			}
 
-			return cmd.Run(c.Context, log, cfg, ip, port, o)
+			return cmd.Run(c.Context, log, cfg, ip, port, c.Uint(readBufferSizeFlagName), o)
 		},
 		Flags: []cli.Flag{
 			shared.ConfigFileFlag,
@@ -158,6 +159,11 @@ func NewCommand(log *zap.Logger) *cli.Command { //nolint:funlen
 				Usage:   "catch all pages",
 				EnvVars: []string{env.CatchAll.String()},
 			},
+			&cli.UintFlag{
+				Name:    readBufferSizeFlagName,
+				Usage:   "read buffer size (0 = use default value)",
+				EnvVars: []string{env.ReadBufferSize.String()},
+			},
 		},
 	}
 
@@ -166,7 +172,13 @@ func NewCommand(log *zap.Logger) *cli.Command { //nolint:funlen
 
 // Run current command.
 func (cmd *command) Run( //nolint:funlen
-	parentCtx context.Context, log *zap.Logger, cfg *config.Config, ip string, port uint16, opt options.ErrorPage,
+	parentCtx context.Context,
+	log *zap.Logger,
+	cfg *config.Config,
+	ip string,
+	port uint16,
+	readBufferSize uint,
+	opt options.ErrorPage,
 ) error {
 	var (
 		ctx, cancel = context.WithCancel(parentCtx) // serve context creation
@@ -226,7 +238,7 @@ func (cmd *command) Run( //nolint:funlen
 	}
 
 	// create HTTP server
-	server := appHttp.NewServer(log)
+	server := appHttp.NewServer(log, readBufferSize)
 
 	// register server routes, middlewares, etc.
 	if err := server.Register(cfg, picker, opt); err != nil {
@@ -239,7 +251,7 @@ func (cmd *command) Run( //nolint:funlen
 	go func(errCh chan<- error) {
 		defer close(errCh)
 
-		log.Info("Server starting",
+		var fields = []zap.Field{
 			zap.String("addr", ip),
 			zap.Uint16("port", port),
 			zap.String("default error page", opt.Default.PageCode),
@@ -248,7 +260,13 @@ func (cmd *command) Run( //nolint:funlen
 			zap.Bool("show request details", opt.ShowDetails),
 			zap.Bool("localization disabled", opt.L10n.Disabled),
 			zap.Bool("catch all enabled", opt.CatchAll),
-		)
+		}
+
+		if readBufferSize > 0 {
+			fields = append(fields, zap.Uint("read buffer size", readBufferSize))
+		}
+
+		log.Info("Server starting", fields...)
 
 		if err := server.Start(ip, port); err != nil {
 			errCh <- err

internal/env/env.go

@@ -19,6 +19,7 @@ const (
 	ProxyHTTPHeaders envVariable = "PROXY_HTTP_HEADERS" // proxy HTTP request headers list (request -> response)
 	DisableL10n      envVariable = "DISABLE_L10N"       // disable pages localization
 	CatchAll         envVariable = "CATCH_ALL"          // catch all pages
+	ReadBufferSize   envVariable = "READ_BUFFER_SIZE"   // https://github.com/tarampampam/error-pages/issues/238
 )
 
 // String returns environment variable name in the string representation.

internal/env/env_test.go

@@ -18,6 +18,7 @@ func TestConstants(t *testing.T) {
 	assert.Equal(t, "PROXY_HTTP_HEADERS", string(ProxyHTTPHeaders))
 	assert.Equal(t, "DISABLE_L10N", string(DisableL10n))
 	assert.Equal(t, "CATCH_ALL", string(CatchAll))
+	assert.Equal(t, "READ_BUFFER_SIZE", string(ReadBufferSize))
 }
 
 func TestEnvVariable_Lookup(t *testing.T) {
@@ -34,6 +35,7 @@ func TestEnvVariable_Lookup(t *testing.T) {
 		{giveEnv: ProxyHTTPHeaders},
 		{giveEnv: DisableL10n},
 		{giveEnv: CatchAll},
+		{giveEnv: ReadBufferSize},
 	}
 
 	for _, tt := range cases {

internal/http/server.go

@@ -39,13 +39,14 @@ const (
 	defaultIdleTimeout  = time.Second * 6
 )
 
-func NewServer(log *zap.Logger) Server {
+func NewServer(log *zap.Logger, readBufferSize uint) Server {
 	rdr := tpl.NewTemplateRenderer()
 
 	return Server{
 		// fasthttp docs: <https://github.com/valyala/fasthttp>
 		fast: &fasthttp.Server{
 			WriteTimeout:          defaultWriteTimeout,
+			ReadBufferSize:        int(readBufferSize),
 			ReadTimeout:           defaultReadTimeout,
 			IdleTimeout:           defaultIdleTimeout,
 			NoDefaultServerHeader: true,