fix: stop redirecting away from wildcard url (coder#6113)

Fixes coder#6097.

Author: kylecarbs

cli/server.go

@@ -723,7 +723,7 @@ func Server(vip *viper.Viper, newAPI func(context.Context, *coderd.Options) (*co
 			// the request is not to a local IP.
 			var handler http.Handler = coderAPI.RootHandler
 			if cfg.RedirectToAccessURL.Value {
-				handler = redirectToAccessURL(handler, accessURLParsed, tunnel != nil)
+				handler = redirectToAccessURL(handler, accessURLParsed, tunnel != nil, appHostnameRegex)
 			}
 
 			// ReadHeaderTimeout is purposefully not enabled. It caused some
@@ -1470,7 +1470,7 @@ func configureHTTPClient(ctx context.Context, clientCertFile, clientKeyFile stri
 }
 
 // nolint:revive
-func redirectToAccessURL(handler http.Handler, accessURL *url.URL, tunnel bool) http.Handler {
+func redirectToAccessURL(handler http.Handler, accessURL *url.URL, tunnel bool, appHostnameRegex *regexp.Regexp) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		redirect := func() {
 			http.Redirect(w, r, accessURL.String(), http.StatusTemporaryRedirect)
@@ -1484,12 +1484,17 @@ func redirectToAccessURL(handler http.Handler, accessURL *url.URL, tunnel bool)
 			return
 		}
 
-		if r.Host != accessURL.Host {
-			redirect()
+		if r.Host == accessURL.Host {
+			handler.ServeHTTP(w, r)
+			return
+		}
+
+		if appHostnameRegex != nil && appHostnameRegex.MatchString(r.Host) {
+			handler.ServeHTTP(w, r)
 			return
 		}
 
-		handler.ServeHTTP(w, r)
+		redirect()
 	})
 }
 

cli/server_test.go

@@ -32,6 +32,7 @@ import (
 
 	"github.com/coder/coder/cli/clitest"
 	"github.com/coder/coder/cli/config"
+	"github.com/coder/coder/coderd/coderdtest"
 	"github.com/coder/coder/coderd/database/postgres"
 	"github.com/coder/coder/coderd/telemetry"
 	"github.com/coder/coder/codersdk"
@@ -70,11 +71,7 @@ func TestServer(t *testing.T) {
 		accessURL := waitAccessURL(t, cfg)
 		client := codersdk.New(accessURL)
 
-		_, err = client.CreateFirstUser(ctx, codersdk.CreateFirstUserRequest{
-			Email:    "some@one.com",
-			Username: "example",
-			Password: "password",
-		})
+		_, err = client.CreateFirstUser(ctx, coderdtest.FirstUserParams)
 		require.NoError(t, err)
 		cancelFunc()
 		require.NoError(t, <-errC)
@@ -540,6 +537,7 @@ func TestServer(t *testing.T) {
 			tlsListener  bool
 			redirect     bool
 			accessURL    string
+			requestURL   string
 			// Empty string means no redirect.
 			expectRedirect string
 		}{
@@ -558,6 +556,14 @@ func TestServer(t *testing.T) {
 				accessURL:      "https://example.com",
 				expectRedirect: "",
 			},
+			{
+				name:           "NoRedirectWithWildcard",
+				tlsListener:    true,
+				accessURL:      "https://example.com",
+				requestURL:     "https://dev.example.com",
+				expectRedirect: "",
+				redirect:       true,
+			},
 			{
 				name:           "NoTLSListener",
 				httpListener:   true,
@@ -583,6 +589,10 @@ func TestServer(t *testing.T) {
 				ctx, cancelFunc := context.WithCancel(context.Background())
 				defer cancelFunc()
 
+				if c.requestURL == "" {
+					c.requestURL = c.accessURL
+				}
+
 				httpListenAddr := ""
 				if c.httpListener {
 					httpListenAddr = ":0"
@@ -601,6 +611,7 @@ func TestServer(t *testing.T) {
 						"--tls-address", ":0",
 						"--tls-cert-file", certPath,
 						"--tls-key-file", keyPath,
+						"--wildcard-access-url", "*.example.com",
 					)
 				}
 				if c.accessURL != "" {
@@ -661,7 +672,7 @@ func TestServer(t *testing.T) {
 
 				// Verify TLS
 				if c.tlsListener {
-					accessURLParsed, err := url.Parse(c.accessURL)
+					accessURLParsed, err := url.Parse(c.requestURL)
 					require.NoError(t, err)
 					client := codersdk.New(accessURLParsed)
 					client.HTTPClient = &http.Client{
@@ -679,8 +690,9 @@ func TestServer(t *testing.T) {
 					}
 					defer client.HTTPClient.CloseIdleConnections()
 					_, err = client.HasFirstUser(ctx)
-					require.NoError(t, err)
-
+					if err != nil {
+						require.ErrorContains(t, err, "Invalid application URL")
+					}
 					cancelFunc()
 					require.NoError(t, <-errC)
 				}