Embed the template, add test

setup/base/base.go

@@ -18,8 +18,10 @@ import (
 	"context"
 	"crypto/tls"
 	"database/sql"
+	"embed"
 	"encoding/json"
 	"fmt"
+	"html/template"
 	"io"
 	"net"
 	"net/http"
@@ -65,6 +67,9 @@ import (
 	userapiinthttp "github.com/matrix-org/dendrite/userapi/inthttp"
 )
 
+//go:embed static/*.gotmpl
+var staticContent embed.FS
+
 // BaseDendrite is a base for creating new instances of dendrite. It parses
 // command line flags and config, and exposes methods for creating various
 // resources. All errors are handled by logging then exiting, so all methods
@@ -493,8 +498,16 @@ func (b *BaseDendrite) SetupAndServeHTTP(
 
 	b.ConfigureAdminEndpoints()
 
+	tmpl := template.Must(template.ParseFS(staticContent, "static/*.gotmpl"))
+
 	b.PublicStaticMux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		http.ServeFile(w, r, "static/index.html")
+		if err := tmpl.ExecuteTemplate(w, "index.gotmpl", map[string]string{
+			"Version": internal.VersionString(),
+		}); err != nil {
+			logrus.WithError(err).Error("failed to execute landing page template")
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = w.Write([]byte("failed to execute template"))
+		}
 	})
 
 	var clientHandler http.Handler

setup/base/base_test.go

@@ -0,0 +1,57 @@
+package base_test
+
+import (
+	"bytes"
+	"embed"
+	"html/template"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/test/testrig"
+	"github.com/stretchr/testify/assert"
+)
+
+//go:embed static/*.gotmpl
+var staticContent embed.FS
+
+func TestLandingPage(t *testing.T) {
+	// generate the expected result
+	tmpl := template.Must(template.ParseFS(staticContent, "static/*.gotmpl"))
+	expectedRes := &bytes.Buffer{}
+	err := tmpl.ExecuteTemplate(expectedRes, "index.gotmpl", map[string]string{
+		"Version": internal.VersionString(),
+	})
+	assert.NoError(t, err)
+
+	b, _, _ := testrig.Base(nil)
+	defer b.Close()
+
+	// hack: create a server and close it immediately, just to get a random port assigned
+	s := httptest.NewServer(nil)
+	s.Close()
+
+	// start base with the listener and wait for it to be started
+	go b.SetupAndServeHTTP("", config.HTTPAddress(s.URL), nil, nil)
+	time.Sleep(time.Millisecond * 10)
+
+	// When hitting /, we should be redirected to /_matrix/static, which should contain the landing page
+	req, err := http.NewRequest(http.MethodGet, s.URL, nil)
+	assert.NoError(t, err)
+
+	// do the request
+	resp, err := s.Client().Do(req)
+	assert.NoError(t, err)
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+
+	// read the response
+	buf := &bytes.Buffer{}
+	_, err = buf.ReadFrom(resp.Body)
+	assert.NoError(t, err)
+
+	// Using .String() for user friendly output
+	assert.Equal(t, expectedRes.String(), buf.String(), "response mismatch")
+}

setup/base/static/index.gotmpl

@@ -46,7 +46,7 @@
           </g>
       </svg>
     </div>
-    <h1>It works! Dendrite is running</h1>
+    <h1>It works! Dendrite {{ .Version }} is running</h1>
     <p>Your Dendrite server is listening on this port and is ready for messages.</p>
     <p>To use this server you'll need <a href="https://matrix.org/docs/projects/try-matrix-now.html#clients" target="_blank" rel="noopener noreferrer">a Matrix client</a>.
     </p>