Replace www-path with www-proxy option for development (#248)

By adding a new ENV variable called `WOODPECKER_WWW_PROXY` it is possible to serve a webinterface via a proxy configured by the `WOODPECKER_WWW_PROXY` value for development instead of serving the interface from the bundled code or from some folder location as the old `WOODPECKER_WWW` option allowed. Using a proxy allows developing the UI with hot-reloading.

cmd/server/flags.go

@@ -64,9 +64,9 @@ var flags = []cli.Flag{
 		Usage:  "enable quic",
 	},
 	cli.StringFlag{
-		EnvVar: "DRONE_WWW,WOODPECKER_WWW",
-		Name:   "www",
-		Usage:  "serve the website from disk",
+		EnvVar: "WOODPECKER_WWW_PROXY",
+		Name:   "www-proxy",
+		Usage:  "serve the website by using a proxy (used for development)",
 		Hidden: true,
 	},
 	cli.StringSliceFlag{

cmd/server/server.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"net"
 	"net/http"
+	"net/http/httputil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -90,13 +91,30 @@ func loop(c *cli.Context) error {
 	store_ := setupStore(c)
 	setupEvilGlobals(c, store_, remote_)
 
-	// we are switching from gin to httpservermux|treemux,
-	// so if this code looks strange, that is why.
-	tree := setupTree(c)
+	proxyWebUI := c.String("www-proxy")
+
+	var webUIServe func(w http.ResponseWriter, r *http.Request)
+
+	if proxyWebUI == "" {
+		// we are switching from gin to httpservermux|treemux,
+		webUIServe = setupTree(c).ServeHTTP
+	} else {
+		origin, _ := url.Parse(proxyWebUI)
+
+		director := func(req *http.Request) {
+			req.Header.Add("X-Forwarded-Host", req.Host)
+			req.Header.Add("X-Origin-Host", origin.Host)
+			req.URL.Scheme = origin.Scheme
+			req.URL.Host = origin.Host
+		}
+
+		proxy := &httputil.ReverseProxy{Director: director}
+		webUIServe = proxy.ServeHTTP
+	}
 
 	// setup the server and start the listener
 	handler := router.Load(
-		tree,
+		webUIServe,
 		ginrus.Ginrus(logrus.StandardLogger(), time.RFC3339, true),
 		middleware.Version,
 		middleware.Config(c),

cmd/server/setup.go

@@ -209,7 +209,6 @@ func setupCoding(c *cli.Context) (remote.Remote, error) {
 func setupTree(c *cli.Context) *httptreemux.ContextMux {
 	tree := httptreemux.NewContextMux()
 	web.New(
-		web.WithDir(c.String("www")),
 		web.WithSync(time.Hour*72),
 		web.WithDocs(c.String("docs")),
 	).Register(tree)

server/router/router.go

@@ -17,7 +17,6 @@ package router
 import (
 	"net/http"
 
-	"github.com/dimfeld/httptreemux"
 	"github.com/gin-gonic/gin"
 
 	"github.com/woodpecker-ci/woodpecker/server/api"
@@ -30,7 +29,7 @@ import (
 )
 
 // Load loads the router
-func Load(mux *httptreemux.ContextMux, middleware ...gin.HandlerFunc) http.Handler {
+func Load(serveHTTP func(w http.ResponseWriter, r *http.Request), middleware ...gin.HandlerFunc) http.Handler {
 
 	e := gin.New()
 	e.Use(gin.Recovery())
@@ -49,7 +48,7 @@ func Load(mux *httptreemux.ContextMux, middleware ...gin.HandlerFunc) http.Handl
 				session.User(c),
 			),
 		)
-		mux.ServeHTTP(c.Writer, req)
+		serveHTTP(c.Writer, req)
 	})
 
 	e.GET("/logout", api.GetLogout)

server/web/opts.go

@@ -19,7 +19,6 @@ import "time"
 // Options defines website handler options.
 type Options struct {
 	sync time.Duration
-	path string
 	docs string
 }
 
@@ -34,14 +33,6 @@ func WithSync(d time.Duration) Option {
 	}
 }
 
-// WithDir configures the website handler with the directory value
-// used to serve the website from the local filesystem.
-func WithDir(s string) Option {
-	return func(o *Options) {
-		o.path = s
-	}
-}
-
 // WithDocs configures the website handler with the documentation
 // website address, which should be included in the user interface.
 func WithDocs(s string) Option {

server/web/opts_test.go

@@ -27,14 +27,6 @@ func TestWithSync(t *testing.T) {
 	}
 }
 
-func TestWithDir(t *testing.T) {
-	opts := new(Options)
-	WithDir("/tmp/www")(opts)
-	if got, want := opts.path, "/tmp/www"; got != want {
-		t.Errorf("Want www directory %q, got %q", want, got)
-	}
-}
-
 func TestWithDocs(t *testing.T) {
 	opts := new(Options)
 	WithDocs("http://docs.drone.io")(opts)

server/web/web.go

@@ -19,9 +19,7 @@ import (
 	"crypto/md5"
 	"fmt"
 	"html/template"
-	"io/ioutil"
 	"net/http"
-	"path/filepath"
 	"time"
 
 	"github.com/woodpecker-ci/woodpecker/model"
@@ -45,10 +43,6 @@ func New(opt ...Option) Endpoint {
 		f(opts)
 	}
 
-	if opts.path != "" {
-		return fromPath(opts)
-	}
-
 	return &website{
 		fs:   dist.New(),
 		opts: opts,
@@ -58,19 +52,6 @@ func New(opt ...Option) Endpoint {
 	}
 }
 
-func fromPath(opts *Options) *website {
-	f := filepath.Join(opts.path, "index.html")
-	b, err := ioutil.ReadFile(f)
-	if err != nil {
-		panic(err)
-	}
-	return &website{
-		fs:   http.Dir(opts.path),
-		tmpl: mustCreateTemplate(string(b)),
-		opts: opts,
-	}
-}
-
 type website struct {
 	opts *Options
 	fs   http.FileSystem