feat: Support configurable base path for server (#714)

docs/source/config.rst

@@ -25,6 +25,7 @@ Server Configuration
 ~~~~~~~~~~~~~~~~~~
 - ``DAGU_HOST`` (``127.0.0.1``): Server binding host
 - ``DAGU_PORT`` (``8080``): Server binding port
+- ``DAGU_BASE_PATH`` (``""``): Base path to serve the application
 - ``DAGU_TZ`` (``""``): Server timezone (default: system timezone)
 - ``DAGU_CERT_FILE``: SSL certificate file path
 - ``DAGU_KEY_FILE``: SSL key file path
@@ -59,6 +60,7 @@ Create ``admin.yaml`` in ``$HOME/.config/dagu/`` to override default settings. B
     # Server Configuration
     host: "127.0.0.1"                # Web UI hostname
     port: 8080                       # Web UI port
+    basePath: ""                    # Base path to serve the application
     tz: "Asia/Tokyo"                 # Timezone (e.g., "America/New_York")
     
     # Directory Configuration

internal/config/config.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"path"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -52,6 +53,7 @@ type Config struct {
 	IsAuthToken        bool           // Enable auth token for API
 	AuthToken          string         // Auth token for API
 	LatestStatusToday  bool           // Show latest status today or the latest status
+	BasePath           string         // Base path for the server
 	APIBaseURL         string         // Base URL for API
 	Debug              bool           // Enable debug mode (verbose logging)
 	LogFormat          string         // Log format
@@ -118,6 +120,18 @@ func Load() (*Config, error) {
 		cfg.Location = time.Local
 	}
 
+	if cfg.BasePath != "" {
+		cfg.BasePath = path.Clean(cfg.BasePath)
+
+		if !path.IsAbs(cfg.BasePath) {
+			cfg.BasePath = path.Join("/", cfg.BasePath)
+		}
+
+		if cfg.BasePath == "/" {
+			cfg.BasePath = ""
+		}
+	}
+
 	return &cfg, nil
 }
 
@@ -168,6 +182,7 @@ func setupViper() error {
 	viper.SetDefault("host", "127.0.0.1")
 	viper.SetDefault("port", "8080")
 	viper.SetDefault("navbarTitle", "Dagu")
+	viper.SetDefault("basePath", "")
 	viper.SetDefault("apiBaseURL", "/api/v1")
 
 	// Set executable path
@@ -198,6 +213,7 @@ func bindEnvs() {
 	_ = viper.BindEnv("logEncodingCharset", "DAGU_LOG_ENCODING_CHARSET")
 	_ = viper.BindEnv("navbarColor", "DAGU_NAVBAR_COLOR")
 	_ = viper.BindEnv("navbarTitle", "DAGU_NAVBAR_TITLE")
+	_ = viper.BindEnv("basePath", "DAGU_BASE_PATH")
 	_ = viper.BindEnv("apiBaseURL", "DAGU_API_BASE_URL")
 	_ = viper.BindEnv("tz", "DAGU_TZ")
 

internal/frontend/frontend.go

@@ -42,6 +42,7 @@ func New(cfg *config.Config, lg logger.Logger, cli client.Client) *server.Server
 		AssetsFS:    assetsFS,
 		NavbarColor: cfg.NavbarColor,
 		NavbarTitle: cfg.NavbarTitle,
+		BasePath:    cfg.BasePath,
 		APIBaseURL:  cfg.APIBaseURL,
 		TimeZone:    cfg.TZ,
 	}

internal/frontend/middleware/global.go

@@ -72,13 +72,15 @@ var (
 	authBasic      *AuthBasic
 	authToken      *AuthToken
 	appLogger      logger.Logger
+	basePath       string
 )
 
 type Options struct {
 	Handler   http.Handler
 	AuthBasic *AuthBasic
 	AuthToken *AuthToken
 	Logger    logger.Logger
+	BasePath  string
 }
 
 type AuthBasic struct {
@@ -95,16 +97,24 @@ func Setup(opts *Options) {
 	authBasic = opts.AuthBasic
 	authToken = opts.AuthToken
 	appLogger = opts.Logger
+	basePath = opts.BasePath
 }
 
 func prefixChecker(next http.Handler) http.Handler {
 	return http.HandlerFunc(
 		func(w http.ResponseWriter, r *http.Request) {
-			if strings.HasPrefix(r.URL.Path, "/api") {
-				next.ServeHTTP(w, r)
-			} else {
-				defaultHandler.ServeHTTP(w, r)
+			if basePath != "" && r.URL.Path == "/" {
+				http.Redirect(w, r, basePath, http.StatusSeeOther)
+				return
 			}
+
+			http.StripPrefix(basePath, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if strings.HasPrefix(r.URL.Path, "/api") {
+					next.ServeHTTP(w, r)
+				} else {
+					defaultHandler.ServeHTTP(w, r)
+				}
+			})).ServeHTTP(w, r)
 		})
 }
 

internal/frontend/server/server.go

@@ -62,6 +62,7 @@ type NewServerArgs struct {
 	// Configuration for the frontend
 	NavbarColor string
 	NavbarTitle string
+	BasePath    string
 	APIBaseURL  string
 	TimeZone    string
 }
@@ -92,6 +93,7 @@ func New(params NewServerArgs) *Server {
 		funcsConfig: funcsConfig{
 			NavbarColor: params.NavbarColor,
 			NavbarTitle: params.NavbarTitle,
+			BasePath:    params.BasePath,
 			APIBaseURL:  params.APIBaseURL,
 			TZ:          params.TimeZone,
 		},
@@ -110,8 +112,9 @@ func (svr *Server) Shutdown() {
 
 func (svr *Server) Serve(ctx context.Context) (err error) {
 	middlewareOptions := &pkgmiddleware.Options{
-		Handler: svr.defaultRoutes(chi.NewRouter()),
-		Logger:  svr.logger,
+		Handler:  svr.defaultRoutes(chi.NewRouter()),
+		Logger:   svr.logger,
+		BasePath: svr.funcsConfig.BasePath,
 	}
 	if svr.authToken != nil {
 		middlewareOptions.AuthToken = &pkgmiddleware.AuthToken{

internal/frontend/server/templates.go

@@ -19,6 +19,7 @@ import (
 	"bytes"
 	"io"
 	"net/http"
+	"path"
 	"path/filepath"
 	"text/template"
 
@@ -56,6 +57,7 @@ func (srv *Server) useTemplate(
 type funcsConfig struct {
 	NavbarColor string
 	NavbarTitle string
+	BasePath    string
 	APIBaseURL  string
 	TZ          string
 }
@@ -78,8 +80,11 @@ func defaultFunctions(cfg funcsConfig) template.FuncMap {
 		"navbarTitle": func() string {
 			return cfg.NavbarTitle
 		},
+		"basePath": func() string {
+			return cfg.BasePath
+		},
 		"apiURL": func() string {
-			return cfg.APIBaseURL
+			return path.Join(cfg.BasePath, cfg.APIBaseURL)
 		},
 		"tz": func() string {
 			return cfg.TZ

internal/frontend/templates/base.gohtml

@@ -10,14 +10,15 @@
             function getConfig() {
                 return {
                     apiURL: "{{ apiURL }}",
+                    basePath: "{{ basePath }}",
                     title: "{{ navbarTitle }}",
                     navbarColor: "{{ navbarColor }}",
                     version: "{{ version }}",
                     tz: "{{ tz }}",
                 };
             }
         </script>
-        <script defer="defer" src="/assets/bundle.js?v={{ version }}"></script>
+        <script defer="defer" src="{{ basePath }}/assets/bundle.js?v={{ version }}"></script>
     </head>
     <body>
         {{template "content" .}}

ui/src/App.tsx

@@ -37,7 +37,7 @@ function App({ config }: Props) {
       >
         <ConfigContext.Provider value={config}>
           <UserPreferencesProvider>
-            <BrowserRouter>
+            <BrowserRouter basename={config.basePath}>
               <Layout {...config}>
                 <Routes>
                   <Route path="/" element={<Dashboard />} />

ui/src/contexts/ConfigContext.tsx

@@ -2,6 +2,7 @@ import { createContext, useContext } from 'react';
 
 export type Config = {
   apiURL: string;
+  basePath: string;
   title: string;
   navbarColor: string;
   tz: string;

ui/webpack.prod.js

@@ -21,7 +21,7 @@ module.exports = merge(common, {
   output: {
     filename: 'bundle.js',
     path: path.resolve(__dirname, 'dist'),
-    publicPath: '/assets/',
+    publicPath: 'auto',
     clean: true,
   },
 });