Add -base-path flag (#762)

This allows self-hosting GoatCounter and reverse proxying it into a
subdirectory instead of hosting it on its own subdomain.

Fixes #707, #750

Co-authored-by: Martin Tournoij <martin@arp242.net>

cmd/goatcounter/saas.go

@@ -80,10 +80,10 @@ func cmdSaas(f zli.Flags, ready chan<- struct{}, stop chan struct{}) error {
 		hosts := map[string]http.Handler{
 			d:          zhttp.RedirectHost("//www." + domain),
 			"www." + d: handlers.NewWebsite(db, dev),
-			"*":        handlers.NewBackend(db, acmeh, dev, c.GoatcounterCom, websocket, c.DomainStatic, 15, apiMax),
+			"*":        handlers.NewBackend(db, acmeh, dev, c.GoatcounterCom, websocket, c.DomainStatic, c.BasePath, 15, apiMax),
 		}
 		if dev {
-			hosts[znet.RemovePort(domainStatic)] = handlers.NewStatic(chi.NewRouter(), dev, true)
+			hosts[znet.RemovePort(domainStatic)] = handlers.NewStatic(chi.NewRouter(), dev, true, c.BasePath)
 		}
 
 		return doServe(ctx, db, listen, listenTLS, tlsc, hosts, stop, func() {

cmd/goatcounter/serve.go

@@ -81,6 +81,12 @@ Flags:
   -public-port Port your site is publicly accessible on. Only needed if it's
                not 80 or 443.
 
+  -base-path   Path under which GoatCounter is available. Usually GoatCounter
+               runs on its own domain or subdomain ("stats.example.com"), but in
+               some cases it's useful to run GoatCounter under a path
+               ("example.com/stats"), in which case you'll need to set this to
+               "/stats".
+
   -automigrate Automatically run all pending migrations on startup.
 
   -smtp        SMTP relay server, as URL (e.g. "smtp://user:pass@server").
@@ -164,18 +170,25 @@ func cmdServe(f zli.Flags, ready chan<- struct{}, stop chan struct{}) error {
 	var (
 		// TODO(depr): -port is for compat with <2.0
 		port         = f.Int(0, "public-port", "port").Pointer()
+		basePath     = f.String("/", "base-path").Pointer()
 		domainStatic = f.String("", "static").Pointer()
 	)
 	dbConnect, dbConn, dev, automigrate, listen, flagTLS, from, websocket, apiMax, err := flagsServe(f, &v)
 	if err != nil {
 		return err
 	}
 
-	return func(port int, domainStatic string) error {
+	return func(port int, basePath, domainStatic string) error {
 		if flagTLS == "" {
 			flagTLS = map[bool]string{true: "http", false: "acme,rdr"}[dev]
 		}
 
+		basePath = strings.Trim(basePath, "/")
+		if basePath != "" {
+			basePath = "/" + basePath
+		}
+		zhttp.BasePath = basePath
+
 		var domainCount, urlStatic string
 		if domainStatic != "" {
 			if p := strings.Index(domainStatic, ":"); p > -1 {
@@ -185,6 +198,8 @@ func cmdServe(f zli.Flags, ready chan<- struct{}, stop chan struct{}) error {
 			}
 			urlStatic = "//" + domainStatic
 			domainCount = domainStatic
+		} else {
+			urlStatic = basePath
 		}
 
 		//from := flagFrom(from, "cfg.Domain", &v)
@@ -206,17 +221,18 @@ func cmdServe(f zli.Flags, ready chan<- struct{}, stop chan struct{}) error {
 		c.DomainStatic = domainStatic
 		c.Dev = dev
 		c.URLStatic = urlStatic
+		c.BasePath = basePath
 		c.DomainCount = domainCount
 		c.Websocket = websocket
 
 		// Set up HTTP handler and servers.
 		hosts := map[string]http.Handler{
-			"*": handlers.NewBackend(db, acmeh, dev, c.GoatcounterCom, websocket, c.DomainStatic, 60, apiMax),
+			"*": handlers.NewBackend(db, acmeh, dev, c.GoatcounterCom, websocket, c.DomainStatic, c.BasePath, 60, apiMax),
 		}
 		if domainStatic != "" {
 			// May not be needed, but just in case the DomainStatic isn't an
 			// external CDN.
-			hosts[znet.RemovePort(domainStatic)] = handlers.NewStatic(chi.NewRouter(), dev, false)
+			hosts[znet.RemovePort(domainStatic)] = handlers.NewStatic(chi.NewRouter(), dev, false, c.BasePath)
 		}
 
 		cnames, err := lsSites(ctx)
@@ -238,7 +254,7 @@ func cmdServe(f zli.Flags, ready chan<- struct{}, stop chan struct{}) error {
 			}
 			ready <- struct{}{}
 		})
-	}(*port, *domainStatic)
+	}(*port, *basePath, *domainStatic)
 }
 
 func doServe(ctx context.Context, db zdb.DB,

context.go

@@ -42,6 +42,7 @@ type GlobalConfig struct {
 	Domain         string
 	DomainStatic   string
 	DomainCount    string
+	BasePath       string
 	URLStatic      string
 	Dev            bool
 	GoatcounterCom bool

go.mod

@@ -35,7 +35,7 @@ require (
 	zgo.at/zcache v1.2.0
 	zgo.at/zcache/v2 v2.1.0
 	zgo.at/zdb v0.0.0-20240818155550-1a862f98cab0
-	zgo.at/zhttp v0.0.0-20240812113805-6333261ded60
+	zgo.at/zhttp v0.0.0-20240819012318-b761c83c740e
 	zgo.at/zli v0.0.0-20240614180544-47534b1ce136
 	zgo.at/zlog v0.0.0-20211017235224-dd4772ddf860
 	zgo.at/zprof v0.0.0-20211217104121-c3c12596d8f0

handlers/backend.go

@@ -19,19 +19,28 @@ import (
 	"zgo.at/zstd/zfs"
 )
 
-func NewBackend(db zdb.DB, acmeh http.HandlerFunc, dev, goatcounterCom, websocket bool, domainStatic string, dashTimeout, apiMax int) chi.Router {
-	r := chi.NewRouter()
+func NewBackend(db zdb.DB, acmeh http.HandlerFunc, dev, goatcounterCom, websocket bool,
+	domainStatic string, basePath string, dashTimeout, apiMax int,
+) chi.Router {
+
+	root := chi.NewRouter()
+	r := root
+	if basePath != "" {
+		r = chi.NewRouter()
+		root.Mount(basePath, r)
+	}
+
 	backend{dashTimeout, websocket}.Mount(r, db, dev, domainStatic, dashTimeout, apiMax)
 
 	if acmeh != nil {
 		r.Get("/.well-known/acme-challenge/{key}", acmeh)
 	}
 
 	if !goatcounterCom {
-		NewStatic(r, dev, goatcounterCom)
+		NewStatic(r, dev, goatcounterCom, basePath)
 	}
 
-	return r
+	return root
 }
 
 type backend struct {

handlers/backend_test.go

@@ -249,5 +249,5 @@ func BenchmarkCount(b *testing.B) {
 }
 
 func newBackend(db zdb.DB) chi.Router {
-	return NewBackend(db, nil, true, true, false, "example.com", 10, 0)
+	return NewBackend(db, nil, true, true, false, "example.com", "", 10, 0)
 }

handlers/dashboard.go

@@ -110,10 +110,7 @@ func (h backend) dashboard(w http.ResponseWriter, r *http.Request) error {
 
 	cd := goatcounter.Config(r.Context()).DomainCount
 	if cd == "" {
-		cd = Site(r.Context()).Domain(r.Context())
-		if goatcounter.Config(r.Context()).Port != "" {
-			cd += ":" + goatcounter.Config(r.Context()).Port
-		}
+		cd = Site(r.Context()).SchemelessURL(r.Context())
 	}
 
 	args := widgets.Args{

handlers/handlers.go

@@ -60,6 +60,7 @@ type Globals struct {
 	User           *goatcounter.User
 	Site           *goatcounter.Site
 	Path           string
+	Base           string
 	Flash          *zhttp.FlashMessage
 	Static         string
 	StaticDomain   string
@@ -79,11 +80,17 @@ func (g Globals) T(msg string, data ...any) template.HTML {
 
 func newGlobals(w http.ResponseWriter, r *http.Request) Globals {
 	ctx := r.Context()
+	base := goatcounter.Config(ctx).BasePath
+	path := strings.TrimPrefix(r.URL.Path, base)
+	if path == "" {
+		path = "/"
+	}
 	g := Globals{
 		Context:        ctx,
 		User:           goatcounter.GetUser(ctx),
 		Site:           goatcounter.GetSite(ctx),
-		Path:           r.URL.Path,
+		Path:           path,
+		Base:           base,
 		Flash:          zhttp.ReadFlash(w, r),
 		Static:         goatcounter.Config(ctx).URLStatic,
 		Domain:         goatcounter.Config(ctx).Domain,
@@ -124,7 +131,7 @@ func newGlobals(w http.ResponseWriter, r *http.Request) Globals {
 	return g
 }
 
-func NewStatic(r chi.Router, dev, goatcounterCom bool) chi.Router {
+func NewStatic(r chi.Router, dev, goatcounterCom bool, basePath string) chi.Router {
 	var cache map[string]int
 	if !dev {
 		cache = map[string]int{
@@ -141,6 +148,9 @@ func NewStatic(r chi.Router, dev, goatcounterCom bool) chi.Router {
 	s.Header("/count.js", map[string]string{
 		"Cross-Origin-Resource-Policy": "cross-origin",
 	})
-	r.Get("/*", s.ServeHTTP)
+	r.Get("/*", func(w http.ResponseWriter, r *http.Request) {
+		r.URL.Path = strings.TrimPrefix(r.URL.Path, basePath)
+		s.ServeHTTP(w, r)
+	})
 	return r
 }

handlers/i18n.go

@@ -140,7 +140,7 @@ func (h i18n) show(w http.ResponseWriter, r *http.Request) error {
 
 	return zhttp.Template(w, "i18n_show.gohtml", struct {
 		Globals
-		Base       msgfile.File
+		BaseFile   msgfile.File
 		File       msgfile.File
 		TOMLFile   string
 		FormatLink func(string) string

handlers/mw.go

@@ -37,7 +37,7 @@ var Started time.Time
 var (
 	redirect = func(w http.ResponseWriter, r *http.Request) error {
 		zhttp.Flash(w, "Need to log in")
-		return guru.Errorf(303, "/user/new")
+		return guru.Errorf(303, goatcounter.Config(r.Context()).BasePath+"/user/new")
 	}
 
 	loggedIn = auth.Filter(func(w http.ResponseWriter, r *http.Request) error {
@@ -76,7 +76,7 @@ var (
 				Secure:   zhttp.CookieSecure,
 				SameSite: zhttp.CookieSameSite,
 			})
-			return guru.Errorf(303, "/")
+			return guru.Errorf(303, goatcounter.Config(r.Context()).BasePath+"/")
 		}
 		if c, err := r.Cookie("access-token"); err == nil && s.Settings.CanView(c.Value) {
 			return nil
@@ -220,7 +220,7 @@ func addctx(db zdb.DB, loadSite bool, dashTimeout int) func(http.Handler) http.H
 
 func noSites(db zdb.DB, w http.ResponseWriter, r *http.Request) {
 	if r.URL.Path != "/" {
-		w.Header().Set("Location", "/")
+		w.Header().Set("Location", goatcounter.Config(r.Context()).BasePath+"/")
 		w.WriteHeader(307)
 		return
 	}
@@ -302,11 +302,12 @@ func noSites(db zdb.DB, w http.ResponseWriter, r *http.Request) {
 	}
 
 	err := zhttp.Template(w, "serve_newsite.gohtml", struct {
+		Globals
 		Validate *zvalidate.Validator
 		Error    error
 		Email    string
 		Cname    string
-	}{&v, tplErr, args.Email, args.Cname})
+	}{newGlobals(w, r), &v, tplErr, args.Email, args.Cname})
 	if err != nil {
 		zlog.Error(err)
 	}

handlers/user.go

@@ -536,7 +536,7 @@ func (h user) verify(w http.ResponseWriter, r *http.Request) error {
 	return zhttp.SeeOther(w, "/")
 }
 
-// Make sure to use the currect cookie, since both "custom.example.com" and
+// Make sure to use the correct cookie, since both "custom.example.com" and
 // "example.goatcounter.com" will work if you're using a custom domain.
 func cookieDomain(site *goatcounter.Site, r *http.Request) string {
 	if r.Host == site.Domain(r.Context()) {

handlers/website.go

@@ -394,7 +394,7 @@ func (h website) doSignup(w http.ResponseWriter, r *http.Request) error {
 		}
 	})
 
-	return zhttp.SeeOther(w, fmt.Sprintf("%s/user/new", site.URL(r.Context())))
+	return zhttp.SeeOther(w, site.URL(r.Context())+"/user/new")
 }
 
 func (h website) forgot(err error, email, turingTest string) zhttp.HandlerFunc {
@@ -481,11 +481,7 @@ func (h website) help(w http.ResponseWriter, r *http.Request) error {
 
 	dc := goatcounter.Config(r.Context()).DomainCount
 	if dc == "" {
-		dc = Site(r.Context()).Domain(r.Context())
-		port := goatcounter.Config(r.Context()).Port
-		if port != "" {
-			dc += port
-		}
+		dc = Site(r.Context()).SchemelessURL(r.Context())
 	}
 
 	cp := chi.URLParam(r, "*")

public/backend.js

@@ -8,6 +8,7 @@
 	$(document).ready(function() {
 		window.I18N              = JSON.parse($('#js-i18n').text())
 		window.USER_SETTINGS     = JSON.parse($('#js-settings').text())
+		window.BASE_PATH         = $('#js-settings').attr('data-base-path') || ""
 		window.CSRF              = $('#js-settings').attr('data-csrf')
 		window.TZ_OFFSET         = parseInt($('#js-settings').attr('data-offset'), 10) || 0
 		window.SITE_FIRST_HIT_AT = $('#js-settings').attr('data-first-hit-at') * 1000
@@ -25,9 +26,9 @@
 	var report_errors = function() {
 		window.onerror = on_error
 		$(document).on('ajaxError', function(e, xhr, settings, err) {
-			if (settings.url === '/jserr')  // Just in case, otherwise we'll be stuck.
+			if (settings.url === BASE_PATH + '/jserr')  // Just in case, otherwise we'll be stuck.
 				return
-			if (settings.url === '/load-widget')
+			if (settings.url === BASE_PATH + '/load-widget')
 				return
 			var msg = T("error/load-url", {url: settings.url, error: err})
 			console.error(msg)
@@ -53,7 +54,7 @@
 			return
 
 		jQuery.ajax({
-			url:    '/jserr',
+			url:    BASE_PATH + '/jserr',
 			method: 'POST',
 			data:    {msg: msg, url: url, line: line, column: column, stack: (err||{}).stack, ua: navigator.userAgent, loc: window.location+''},
 		})
@@ -125,7 +126,7 @@
 			e.preventDefault()
 
 			jQuery.ajax({
-				url:     '/settings/main/ip',
+				url:     BASE_PATH + '/settings/main/ip',
 				success: function(data) {
 					var input   = $('[name="settings.ignore_ips"]'),
 						current = input.val().split(',').
@@ -161,7 +162,7 @@
 
 		// Update redirect link.
 		$('#settings-secret').on('change', function(e) {
-			$('#secret-url').val(`${location.protocol}//${location.host}?access-token=${this.value}`)
+			$('#secret-url').val(`${location.protocol}//${location.host}${BASE_PATH}?access-token=${this.value}`)
 		}).trigger('change')
 	}
 
@@ -193,7 +194,7 @@
 				return
 
 			jQuery.ajax({
-				url:     '/user/dashboard/widget/' + this.selectedOptions[0].value,
+				url:     BASE_PATH + '/user/dashboard/widget/' + this.selectedOptions[0].value,
 				success: function(data) {
 					var i    = 1 + $('.index').toArray().map((e) => parseInt(e.value, 10)).sort().pop(),
 						html = $(data.replace(/widgets([\[_])0([\]_])/g, `widgets$1${i}$2`))