Added possibility to disable error pages auto-localization (#94)

CHANGELOG.md

@@ -6,11 +6,16 @@ The format is based on [Keep a Changelog][keepachangelog] and this project adher
 
 ## UNRELEASED
 
+### Added
+
+- Possibility to disable error pages auto-localization (using `--disable-l10n` flag for the `serve` & `build` commands or environment variable `DISABLE_L10N`) [#91]
+
 ### Fixed
 
 - User UID/GID changed to the numeric values in the dockerfile [#92]
 
 [#92]:https://github.com/tarampampam/error-pages/issues/92
+[#91]:https://github.com/tarampampam/error-pages/issues/91
 
 ## v2.12.1
 

Dockerfile

@@ -68,7 +68,8 @@ ENV LISTEN_PORT="8080" \
     TEMPLATE_NAME="ghost" \
     DEFAULT_ERROR_PAGE="404" \
     DEFAULT_HTTP_CODE="404" \
-    SHOW_DETAILS="false"
+    SHOW_DETAILS="false" \
+    DISABLE_L10N="false"
 
 # Docs: <https://docs.docker.com/engine/reference/builder/#healthcheck>
 HEALTHCHECK --interval=7s --timeout=2s CMD ["/bin/error-pages", "healthcheck", "--log-json"]

internal/cli/build/command.go

@@ -15,6 +15,7 @@ import (
 func NewCommand(log *zap.Logger, configFile *string) *cobra.Command {
 	var (
 		generateIndex bool
+		disableL10n   bool
 		cfg           *config.Config
 	)
 
@@ -39,7 +40,7 @@ func NewCommand(log *zap.Logger, configFile *string) *cobra.Command {
 				return errors.New("wrong arguments count")
 			}
 
-			return run(log, cfg, args[0], generateIndex)
+			return run(log, cfg, args[0], generateIndex, disableL10n)
 		},
 	}
 
@@ -50,6 +51,13 @@ func NewCommand(log *zap.Logger, configFile *string) *cobra.Command {
 		"generate index page",
 	)
 
+	cmd.Flags().BoolVarP(
+		&disableL10n,
+		"disable-l10n", "",
+		false,
+		"disable error pages localization",
+	)
+
 	return cmd
 }
 
@@ -60,7 +68,7 @@ const (
 	outDirPerm       = os.FileMode(0775)
 )
 
-func run(log *zap.Logger, cfg *config.Config, outDirectoryPath string, generateIndex bool) error { //nolint:funlen
+func run(log *zap.Logger, cfg *config.Config, outDirectoryPath string, generateIndex, disableL10n bool) error { //nolint:funlen,lll
 	if len(cfg.Templates) == 0 {
 		return errors.New("no loaded templates")
 	}
@@ -92,6 +100,7 @@ func run(log *zap.Logger, cfg *config.Config, outDirectoryPath string, generateI
 				Message:            page.Message(),
 				Description:        page.Description(),
 				ShowRequestDetails: false,
+				L10nDisabled:       disableL10n,
 			})
 			if renderingErr != nil {
 				return renderingErr

internal/cli/serve/command.go

@@ -30,7 +30,7 @@ func NewCommand(ctx context.Context, log *zap.Logger, configFile *string) *cobra
 				return errors.New("path to the config file is required for this command")
 			}
 
-			if err = f.overrideUsingEnv(cmd.Flags()); err != nil {
+			if err = f.OverrideUsingEnv(cmd.Flags()); err != nil {
 				return err
 			}
 
@@ -38,18 +38,18 @@ func NewCommand(ctx context.Context, log *zap.Logger, configFile *string) *cobra
 				return err
 			}
 
-			return f.validate()
+			return f.Validate()
 		},
-		RunE: func(*cobra.Command, []string) error { return run(ctx, log, f, cfg) },
+		RunE: func(*cobra.Command, []string) error { return run(ctx, log, cfg, f) },
 	}
 
-	f.init(cmd.Flags())
+	f.Init(cmd.Flags())
 
 	return cmd
 }
 
 // run current command.
-func run(parentCtx context.Context, log *zap.Logger, f flags, cfg *config.Config) error { //nolint:funlen
+func run(parentCtx context.Context, log *zap.Logger, cfg *config.Config, f flags) error { //nolint:funlen
 	var (
 		ctx, cancel = context.WithCancel(parentCtx) // serve context creation
 		oss         = breaker.NewOSSignals(ctx)     // OS signals listener
@@ -70,9 +70,11 @@ func run(parentCtx context.Context, log *zap.Logger, f flags, cfg *config.Config
 	var (
 		templateNames = cfg.TemplateNames()
 		picker        interface{ Pick() string }
+
+		opt = f.ToOptions()
 	)
 
-	switch f.template.name {
+	switch opt.Template.Name {
 	case useRandomTemplate:
 		log.Info("A random template will be used")
 
@@ -99,28 +101,19 @@ func run(parentCtx context.Context, log *zap.Logger, f flags, cfg *config.Config
 		picker = pick.NewStringsSlice(templateNames, pick.First)
 
 	default:
-		if t, found := cfg.Template(f.template.name); found {
+		if t, found := cfg.Template(opt.Template.Name); found {
 			log.Info("We will use the requested template", zap.String("name", t.Name()))
 			picker = pick.NewStringsSlice([]string{t.Name()}, pick.First)
 		} else {
-			return errors.New("requested nonexistent template: " + f.template.name)
+			return errors.New("requested nonexistent template: " + opt.Template.Name)
 		}
 	}
 
-	var proxyHTTPHeaders = f.HeadersToProxy()
-
 	// create HTTP server
 	server := appHttp.NewServer(log)
 
 	// register server routes, middlewares, etc.
-	if err := server.Register(
+	if err := server.Register(cfg, picker, opt); err != nil {
-		cfg,
-		picker,
-		f.defaultErrorPage,
-		f.defaultHTTPCode,
-		f.showDetails,
-		proxyHTTPHeaders,
-	); err != nil {
 		return err
 	}
 
@@ -131,15 +124,16 @@ func run(parentCtx context.Context, log *zap.Logger, f flags, cfg *config.Config
 		defer close(errCh)
 
 		log.Info("Server starting",
-			zap.String("addr", f.listen.ip),
+			zap.String("addr", f.Listen.IP),
-			zap.Uint16("port", f.listen.port),
+			zap.Uint16("port", f.Listen.Port),
-			zap.String("default error page", f.defaultErrorPage),
+			zap.String("default error page", opt.Default.PageCode),
-			zap.Uint16("default HTTP response code", f.defaultHTTPCode),
+			zap.Uint16("default HTTP response code", opt.Default.HTTPCode),
-			zap.Strings("proxy headers", proxyHTTPHeaders),
+			zap.Strings("proxy headers", opt.ProxyHTTPHeaders),
-			zap.Bool("show request details", f.showDetails),
+			zap.Bool("show request details", opt.ShowDetails),
+			zap.Bool("localization disabled", opt.L10n.Disabled),
 		)
 
-		if err := server.Start(f.listen.ip, f.listen.port); err != nil {
+		if err := server.Start(f.Listen.IP, f.Listen.Port); err != nil {
 			errCh <- err
 		}
 	}(startingErrCh)

internal/cli/serve/flags.go

@@ -9,60 +9,26 @@ import (
 
 	"github.com/spf13/pflag"
 	"github.com/tarampampam/error-pages/internal/env"
+	"github.com/tarampampam/error-pages/internal/options"
 )
 
 type flags struct {
-	listen struct {
+	Listen struct {
-		ip   string
+		IP   string
-		port uint16
+		Port uint16
 	}
 	template struct {
 		name string
 	}
+	l10n struct {
+		disabled bool
+	}
 	defaultErrorPage string
 	defaultHTTPCode  uint16
 	showDetails      bool
 	proxyHTTPHeaders string // comma-separated
 }
 
-// HeadersToProxy converts a comma-separated string with headers list into strings slice (with a sorting and without
-// duplicates).
-func (f *flags) HeadersToProxy() []string {
-	var raw = strings.Split(f.proxyHTTPHeaders, ",")
-
-	if len(raw) == 0 {
-		return []string{}
-	} else if len(raw) == 1 {
-		if h := strings.TrimSpace(raw[0]); h != "" {
-			return []string{h}
-		} else {
-			return []string{}
-		}
-	}
-
-	var m = make(map[string]struct{}, len(raw))
-
-	// make unique and ignore empty strings
-	for _, h := range raw {
-		if h = strings.TrimSpace(h); h != "" {
-			if _, ok := m[h]; !ok {
-				m[h] = struct{}{}
-			}
-		}
-	}
-
-	// convert map into slice
-	var headers = make([]string, 0, len(m))
-	for h := range m {
-		headers = append(headers, h)
-	}
-
-	// make sort
-	sort.Strings(headers)
-
-	return headers
-}
-
 const (
 	listenFlagName           = "listen"
 	portFlagName             = "port"
@@ -71,6 +37,7 @@ const (
 	defaultHTTPCodeFlagName  = "default-http-code"
 	showDetailsFlagName      = "show-details"
 	proxyHTTPHeadersFlagName = "proxy-headers"
+	disableL10nFlagName      = "disable-l10n"
 )
 
 const (
@@ -80,18 +47,18 @@ const (
 	useRandomTemplateHourly        = "random-hourly"
 )
 
-func (f *flags) init(flagSet *pflag.FlagSet) {
+func (f *flags) Init(flagSet *pflag.FlagSet) {
 	flagSet.StringVarP(
-		&f.listen.ip,
+		&f.Listen.IP,
 		listenFlagName, "l",
 		"0.0.0.0",
-		fmt.Sprintf("IP address to listen on [$%s]", env.ListenAddr),
+		fmt.Sprintf("IP address to Listen on [$%s]", env.ListenAddr),
 	)
 	flagSet.Uint16VarP(
-		&f.listen.port,
+		&f.Listen.Port,
 		portFlagName, "p",
 		8080, //nolint:gomnd // must be same as default healthcheck `--port` flag value
-		fmt.Sprintf("TCP port number [$%s]", env.ListenPort),
+		fmt.Sprintf("TCP prt number [$%s]", env.ListenPort),
 	)
 	flagSet.StringVarP(
 		&f.template.name,
@@ -131,22 +98,28 @@ func (f *flags) init(flagSet *pflag.FlagSet) {
 		"",
 		fmt.Sprintf("proxy HTTP request headers list (comma-separated) [$%s]", env.ProxyHTTPHeaders),
 	)
+	flagSet.BoolVarP(
+		&f.l10n.disabled,
+		disableL10nFlagName, "",
+		false,
+		fmt.Sprintf("disable error pages localization [$%s]", env.DisableL10n),
+	)
 }
 
-func (f *flags) overrideUsingEnv(flagSet *pflag.FlagSet) (lastErr error) { //nolint:gocognit,gocyclo
+func (f *flags) OverrideUsingEnv(flagSet *pflag.FlagSet) (lastErr error) { //nolint:gocognit,gocyclo
 	flagSet.VisitAll(func(flag *pflag.Flag) {
 		// flag was NOT defined using CLI (flags should have maximal priority)
 		if !flag.Changed { //nolint:nestif
 			switch flag.Name {
 			case listenFlagName:
 				if envVar, exists := env.ListenAddr.Lookup(); exists {
-					f.listen.ip = strings.TrimSpace(envVar)
+					f.Listen.IP = strings.TrimSpace(envVar)
 				}
 
 			case portFlagName:
 				if envVar, exists := env.ListenPort.Lookup(); exists {
 					if p, err := strconv.ParseUint(envVar, 10, 16); err == nil { //nolint:gomnd
-						f.listen.port = uint16(p)
+						f.Listen.Port = uint16(p)
 					} else {
 						lastErr = fmt.Errorf("wrong TCP port environment variable [%s] value", envVar)
 					}
@@ -182,6 +155,13 @@ func (f *flags) overrideUsingEnv(flagSet *pflag.FlagSet) (lastErr error) { //nol
 				if envVar, exists := env.ProxyHTTPHeaders.Lookup(); exists {
 					f.proxyHTTPHeaders = strings.TrimSpace(envVar)
 				}
+
+			case disableL10nFlagName:
+				if envVar, exists := env.DisableL10n.Lookup(); exists {
+					if b, err := strconv.ParseBool(envVar); err == nil {
+						f.l10n.disabled = b
+					}
+				}
 			}
 		}
 	})
@@ -189,9 +169,9 @@ func (f *flags) overrideUsingEnv(flagSet *pflag.FlagSet) (lastErr error) { //nol
 	return lastErr
 }
 
-func (f *flags) validate() error {
+func (f *flags) Validate() error {
-	if net.ParseIP(f.listen.ip) == nil {
+	if net.ParseIP(f.Listen.IP) == nil {
-		return fmt.Errorf("wrong IP address [%s] for listening", f.listen.ip)
+		return fmt.Errorf("wrong IP address [%s] for listening", f.Listen.IP)
 	}
 
 	if f.defaultHTTPCode > 599 { //nolint:gomnd
@@ -204,3 +184,52 @@ func (f *flags) validate() error {
 
 	return nil
 }
+
+// headersToProxy converts a comma-separated string with headers list into strings slice (with a sorting and without
+// duplicates).
+func (f *flags) headersToProxy() []string {
+	var raw = strings.Split(f.proxyHTTPHeaders, ",")
+
+	if len(raw) == 0 {
+		return []string{}
+	} else if len(raw) == 1 {
+		if h := strings.TrimSpace(raw[0]); h != "" {
+			return []string{h}
+		} else {
+			return []string{}
+		}
+	}
+
+	var m = make(map[string]struct{}, len(raw))
+
+	// make unique and ignore empty strings
+	for _, h := range raw {
+		if h = strings.TrimSpace(h); h != "" {
+			if _, ok := m[h]; !ok {
+				m[h] = struct{}{}
+			}
+		}
+	}
+
+	// convert map into slice
+	var headers = make([]string, 0, len(m))
+	for h := range m {
+		headers = append(headers, h)
+	}
+
+	// make sort
+	sort.Strings(headers)
+
+	return headers
+}
+
+func (f *flags) ToOptions() (o options.ErrorPage) {
+	o.Default.PageCode = f.defaultErrorPage
+	o.Default.HTTPCode = f.defaultHTTPCode
+	o.L10n.Disabled = f.l10n.disabled
+	o.Template.Name = f.template.name
+	o.ShowDetails = f.showDetails
+	o.ProxyHTTPHeaders = f.headersToProxy()
+
+	return o
+}

internal/env/env.go

@@ -14,6 +14,7 @@ const (
 	DefaultHTTPCode  envVariable = "DEFAULT_HTTP_CODE"  // default HTTP response code
 	ShowDetails      envVariable = "SHOW_DETAILS"       // show request details in response
 	ProxyHTTPHeaders envVariable = "PROXY_HTTP_HEADERS" // proxy HTTP request headers list (request -> response)
+	DisableL10n      envVariable = "DISABLE_L10N"       // disable pages localization
 )
 
 // String returns environment variable name in the string representation.

internal/env/env_test.go

@@ -16,6 +16,7 @@ func TestConstants(t *testing.T) {
 	assert.Equal(t, "DEFAULT_HTTP_CODE", string(DefaultHTTPCode))
 	assert.Equal(t, "SHOW_DETAILS", string(ShowDetails))
 	assert.Equal(t, "PROXY_HTTP_HEADERS", string(ProxyHTTPHeaders))
+	assert.Equal(t, "DISABLE_L10N", string(DisableL10n))
 }
 
 func TestEnvVariable_Lookup(t *testing.T) {
@@ -30,6 +31,7 @@ func TestEnvVariable_Lookup(t *testing.T) {
 		{giveEnv: DefaultHTTPCode},
 		{giveEnv: ShowDetails},
 		{giveEnv: ProxyHTTPHeaders},
+		{giveEnv: DisableL10n},
 	}
 
 	for _, tt := range cases {

internal/http/core/errorpage.go

@@ -4,6 +4,7 @@ import (
 	"strconv"
 
 	"github.com/tarampampam/error-pages/internal/config"
+	"github.com/tarampampam/error-pages/internal/options"
 	"github.com/tarampampam/error-pages/internal/tpl"
 	"github.com/valyala/fasthttp"
 )
@@ -24,8 +25,7 @@ func RespondWithErrorPage( //nolint:funlen,gocyclo
 	rdr renderer,
 	pageCode string,
 	httpCode int,
-	showRequestDetails bool,
+	opt options.ErrorPage,
-	proxyHeaders []string,
 ) {
 	ctx.Response.Header.Set("X-Robots-Tag", "noindex") // block Search indexing
 
@@ -33,10 +33,14 @@ func RespondWithErrorPage( //nolint:funlen,gocyclo
 		clientWant    = ClientWantFormat(ctx)
 		json, canJSON = cfg.JSONFormat()
 		xml, canXML   = cfg.XMLFormat()
-		props         = tpl.Properties{Code: pageCode, ShowRequestDetails: showRequestDetails}
+		props         = tpl.Properties{
+			Code:               pageCode,
+			ShowRequestDetails: opt.ShowDetails,
+			L10nDisabled:       opt.L10n.Disabled,
+		}
 	)
 
-	if showRequestDetails {
+	if opt.ShowDetails {
 		props.OriginalURI = string(ctx.Request.Header.Peek(OriginalURI))
 		props.Namespace = string(ctx.Request.Header.Peek(Namespace))
 		props.IngressName = string(ctx.Request.Header.Peek(IngressName))
@@ -66,7 +70,7 @@ func RespondWithErrorPage( //nolint:funlen,gocyclo
 	}
 
 	// proxy required HTTP headers from the request to the response
-	for _, headerToProxy := range proxyHeaders {
+	for _, headerToProxy := range opt.ProxyHTTPHeaders {
 		if reqHeader := ctx.Request.Header.Peek(headerToProxy); len(reqHeader) > 0 {
 			ctx.Response.Header.SetBytesV(headerToProxy, reqHeader)
 		}

internal/http/handlers/errorpage/handler.go

@@ -3,6 +3,7 @@ package errorpage
 import (
 	"github.com/tarampampam/error-pages/internal/config"
 	"github.com/tarampampam/error-pages/internal/http/core"
+	"github.com/tarampampam/error-pages/internal/options"
 	"github.com/tarampampam/error-pages/internal/tpl"
 	"github.com/valyala/fasthttp"
 )
@@ -19,18 +20,12 @@ type (
 )
 
 // NewHandler creates handler for error pages serving.
-func NewHandler(
+func NewHandler(cfg *config.Config, p templatePicker, rdr renderer, opt options.ErrorPage) fasthttp.RequestHandler {
-	cfg *config.Config,
-	p templatePicker,
-	rdr renderer,
-	showRequestDetails bool,
-	proxyHTTPHeaders []string,
-) fasthttp.RequestHandler {
 	return func(ctx *fasthttp.RequestCtx) {
 		core.SetClientFormat(ctx, core.PlainTextContentType) // default content type
 
 		if code, ok := ctx.UserValue("code").(string); ok {
-			core.RespondWithErrorPage(ctx, cfg, p, rdr, code, fasthttp.StatusOK, showRequestDetails, proxyHTTPHeaders)
+			core.RespondWithErrorPage(ctx, cfg, p, rdr, code, fasthttp.StatusOK, opt)
 		} else { // will never occur
 			ctx.SetStatusCode(fasthttp.StatusInternalServerError)
 			_, _ = ctx.WriteString("cannot extract requested code from the request")

internal/http/handlers/index/handler.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/tarampampam/error-pages/internal/config"
 	"github.com/tarampampam/error-pages/internal/http/core"
+	"github.com/tarampampam/error-pages/internal/options"
 	"github.com/tarampampam/error-pages/internal/tpl"
 	"github.com/valyala/fasthttp"
 )
@@ -21,23 +22,15 @@ type (
 )
 
 // NewHandler creates handler for the index page serving.
-func NewHandler(
+func NewHandler(cfg *config.Config, p templatePicker, rdr renderer, opt options.ErrorPage) fasthttp.RequestHandler {
-	cfg *config.Config,
-	p templatePicker,
-	rdr renderer,
-	defaultPageCode string,
-	defaultHTTPCode uint16,
-	showRequestDetails bool,
-	proxyHTTPHeaders []string,
-) fasthttp.RequestHandler {
 	return func(ctx *fasthttp.RequestCtx) {
-		pageCode, httpCode := defaultPageCode, int(defaultHTTPCode)
+		pageCode, httpCode := opt.Default.PageCode, int(opt.Default.HTTPCode)
 
 		if returnCode, ok := extractCodeToReturn(ctx); ok {
 			pageCode, httpCode = strconv.Itoa(returnCode), returnCode
 		}
 
-		core.RespondWithErrorPage(ctx, cfg, p, rdr, pageCode, httpCode, showRequestDetails, proxyHTTPHeaders)
+		core.RespondWithErrorPage(ctx, cfg, p, rdr, pageCode, httpCode, opt)
 	}
 }
 

internal/http/server.go

@@ -15,6 +15,7 @@ import (
 	notfoundHandler "github.com/tarampampam/error-pages/internal/http/handlers/notfound"
 	versionHandler "github.com/tarampampam/error-pages/internal/http/handlers/version"
 	"github.com/tarampampam/error-pages/internal/metrics"
+	"github.com/tarampampam/error-pages/internal/options"
 	"github.com/tarampampam/error-pages/internal/tpl"
 	"github.com/tarampampam/error-pages/internal/version"
 	"github.com/valyala/fasthttp"
@@ -66,14 +67,7 @@ type templatePicker interface {
 
 // Register server routes, middlewares, etc.
 // Router docs: <https://github.com/fasthttp/router>
-func (s *Server) Register(
+func (s *Server) Register(cfg *config.Config, templatePicker templatePicker, opt options.ErrorPage) error {
-	cfg *config.Config,
-	templatePicker templatePicker,
-	defaultPageCode string,
-	defaultHTTPCode uint16,
-	showDetails bool,
-	proxyHTTPHeaders []string,
-) error {
 	reg, m := metrics.NewRegistry(), metrics.NewMetrics()
 
 	if err := m.Register(reg); err != nil {
@@ -82,8 +76,9 @@ func (s *Server) Register(
 
 	s.fast.Handler = common.DurationMetrics(common.LogRequest(s.router.Handler, s.log), &m)
 
-	s.router.GET("/", indexHandler.NewHandler(cfg, templatePicker, s.rdr, defaultPageCode, defaultHTTPCode, showDetails, proxyHTTPHeaders)) //nolint:lll
+	s.router.GET("/", indexHandler.NewHandler(cfg, templatePicker, s.rdr, opt))
-	s.router.GET("/{code}.html", errorpageHandler.NewHandler(cfg, templatePicker, s.rdr, showDetails, proxyHTTPHeaders))                    //nolint:lll
+	s.router.GET("/{code}.html", errorpageHandler.NewHandler(cfg, templatePicker, s.rdr, opt))
+
 	s.router.GET("/version", versionHandler.NewHandler(version.Version()))
 
 	liveHandler := healthzHandler.NewHandler(checkers.NewLiveChecker())

internal/options/errorpage.go

@@ -0,0 +1,16 @@
+package options
+
+type ErrorPage struct {
+	Default struct {
+		PageCode string // default error page code
+		HTTPCode uint16 // default HTTP response code
+	}
+	L10n struct {
+		Disabled bool // disable error pages localization
+	}
+	Template struct {
+		Name string // template name
+	}
+	ShowDetails      bool     // show request details in response
+	ProxyHTTPHeaders []string // proxy HTTP request headers list
+}

internal/tpl/properties.go

@@ -16,6 +16,7 @@ type Properties struct { // only string properties with a "token" tag, please
 	RequestID          string `token:"request_id"`
 	ForwardedFor       string `token:"forwarded_for"`
 	Host               string `token:"host"`
+	L10nDisabled       bool
 	ShowRequestDetails bool
 }
 

internal/tpl/render.go

@@ -142,6 +142,8 @@ func (tr *TemplateRenderer) Render(content []byte, props Properties) ([]byte, er
 	var funcMap = template.FuncMap{
 		"show_details":  func() bool { return props.ShowRequestDetails },
 		"hide_details":  func() bool { return !props.ShowRequestDetails },
+		"l10n_disabled": func() bool { return props.L10nDisabled },
+		"l10n_enabled":  func() bool { return !props.L10nDisabled },
 	}
 
 	// make a copy of template functions map

internal/tpl/render_test.go

@@ -56,6 +56,17 @@ func Test_Render(t *testing.T) {
 			giveProps:   tpl.Properties{Code: "201", Message: "lorem ipsum"},
 			wantContent: `{"code": "201", "message": {"here":[ " Yeah " ]}}`,
 		},
+
+		"fn l10n_enabled": {
+			giveContent: "{{ if l10n_enabled }}Y{{ else }}N{{ end }}",
+			giveProps:   tpl.Properties{L10nDisabled: true},
+			wantContent: "N",
+		},
+		"fn l10n_disabled": {
+			giveContent: "{{ if l10n_disabled }}Y{{ else }}N{{ end }}",
+			giveProps:   tpl.Properties{L10nDisabled: true},
+			wantContent: "Y",
+		},
 	} {
 		t.Run(name, func(t *testing.T) {
 			content, err := renderer.Render([]byte(tt.giveContent), tt.giveProps)

templates/app-down.html

@@ -225,6 +225,7 @@
         }
     });
 
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -233,6 +234,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/cats.html

@@ -104,6 +104,7 @@
     </div>
 </div>
 <script>
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -112,6 +113,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/connection.html

@@ -254,6 +254,7 @@
         console.warn('Cannot parse the error code:', errorCode);
     }
 
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -262,6 +263,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 <!--
     Error {{ code }}: {{ message }}

templates/ghost.html

@@ -98,6 +98,7 @@
     </div>
 </div>
 <script>
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -106,6 +107,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/hacker-terminal.html

@@ -163,6 +163,7 @@
     {{ end }}
 </div>
 <script>
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -171,6 +172,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/l7-dark.html

@@ -82,6 +82,7 @@
     </div>
 </div>
 <script>
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -90,6 +91,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/l7-light.html

@@ -84,6 +84,7 @@
     </div>
 </div>
 <script>
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -92,6 +93,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/lost-in-space.html

@@ -378,6 +378,7 @@
         console.warn('gsap library is not initialized (network error?)')
     }
 
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -386,6 +387,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 
 </body>

templates/matrix.html

@@ -262,6 +262,7 @@
 
     (new Matrix(document.getElementById('matrix'))).run(document.getElementById('matrix-words'));
 
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -270,6 +271,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/noise.html

@@ -175,6 +175,7 @@
         window.clearInterval(flickerInterval);
     });
 
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -183,6 +184,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--

templates/readme.md

@@ -11,7 +11,7 @@ Creating templates is a very simple operation, even for those who know nothing a
 ### Error page & request data
 
 | Signature                            | Description                                                   | Example                                      |
-|-------------------------------------|---------------------------------------------------------------|----------------------------------------------|
+|--------------------------------------|---------------------------------------------------------------|----------------------------------------------|
 | `{{ code }}`                         | Error page code                                               | `404`                                        |
 | `{{ message }}`                      | Error code message                                            | `Not found`                                  |
 | `{{ description }}`                  | Error code description                                        | `The server can not find the requested page` |
@@ -28,6 +28,8 @@ Creating templates is a very simple operation, even for those who know nothing a
 | `{{ version }}`                      | Application version                                           | `2.5.0`                                      |
 | `{{ if show_details }}...{{ end }}`  | Logical operator (server started with "show details" option?) |                                              |
 | `{{ if hide_details }}...{{ end }}`  | Same as above, but inverted                                   |                                              |
+| `{{ if l10n_enabled }}...{{ end }}`  | Logical operator (l10n is enabled?)                           |                                              |
+| `{{ if l10n_disabled }}...{{ end }}` | Same as above, but inverted                                   |                                              |
 
 ### Modifiers
 

templates/shuffle.html

@@ -215,6 +215,7 @@
     }, 550);
     // {{ end }}
 
+    // {{ if l10n_enabled }}
     if (navigator.language.substring(0, 2).toLowerCase() !== 'en') {
         ((s, p) => { // localize the page (details here - https://github.com/tarampampam/error-pages/tree/master/l10n)
             s.src = 'https://cdn.jsdelivr.net/gh/tarampampam/error-pages@2/l10n/l10n.min.js'; // '../l10n/l10n.js';
@@ -223,6 +224,7 @@
             p.appendChild(s);
         })(document.createElement('script'), document.body);
     }
+    // {{ end }}
 </script>
 </body>
 <!--