feat: add version to footer (#882)

* Add endpoint for getting build info

* Add build info XService

* Add version with link to page footer

Partially addresses #376.

* Lift buildinfo package

coderd/coderd.go

@@ -7,16 +7,19 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/render"
 	"google.golang.org/api/idtoken"
 
 	chitrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/go-chi/chi.v5"
 
 	"cdr.dev/slog"
+	"github.com/coder/coder/buildinfo"
 	"github.com/coder/coder/coderd/awsidentity"
 	"github.com/coder/coder/coderd/database"
 	"github.com/coder/coder/coderd/gitsshkey"
 	"github.com/coder/coder/coderd/httpapi"
 	"github.com/coder/coder/coderd/httpmw"
+	"github.com/coder/coder/codersdk"
 	"github.com/coder/coder/site"
 )
 
@@ -59,6 +62,15 @@ func New(options *Options) (http.Handler, func()) {
 				Message: "👋",
 			})
 		})
+		r.Route("/buildinfo", func(r chi.Router) {
+			r.Get("/", func(rw http.ResponseWriter, r *http.Request) {
+				render.Status(r, http.StatusOK)
+				render.JSON(rw, r, codersdk.BuildInfoResponse{
+					ExternalURL: buildinfo.ExternalURL(),
+					Version:     buildinfo.Version(),
+				})
+			})
+		})
 		r.Route("/files", func(r chi.Router) {
 			r.Use(
 				httpmw.ExtractAPIKey(options.Database, nil),

coderd/coderd_test.go

@@ -1,11 +1,26 @@
 package coderd_test
 
 import (
+	"context"
 	"testing"
 
 	"go.uber.org/goleak"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/coder/coder/buildinfo"
+	"github.com/coder/coder/coderd/coderdtest"
 )
 
 func TestMain(m *testing.M) {
 	goleak.VerifyTestMain(m)
 }
+
+func TestBuildInfo(t *testing.T) {
+	t.Parallel()
+	client := coderdtest.New(t, nil)
+	buildInfo, err := client.BuildInfo(context.Background())
+	require.NoError(t, err)
+	require.Equal(t, buildinfo.ExternalURL(), buildInfo.ExternalURL, "external URL")
+	require.Equal(t, buildinfo.Version(), buildInfo.Version, "version")
+}