feat(compute/serve): allow local WebSocket passthrough to be disabled

CHANGELOG.md

@@ -19,6 +19,7 @@
 ### Enhancements:
 
 - feat(audit-log): add event-mapping command group ([#1875](https://github.com/fastly/cli/pull/1875))
+- feat(compute/serve): add `--experimental-websockets-passthrough` flag and `[local_server.websockets_passthrough]` section in `fastly.toml`, allowing local WebSocket passthrough to be disabled (it remains enabled by default)
 
 ### Dependencies:
 

pkg/commands/compute/compute_test.go

@@ -103,6 +103,7 @@ func TestFlagDivergenceServe(t *testing.T) {
 		"addr",
 		"debug",
 		"experimental-enable-pushpin",
+		"experimental-websockets-passthrough",
 		"file",
 		"profile-guest",
 		"pushpin-path",

pkg/commands/compute/serve.go

@@ -63,20 +63,21 @@ type ServeCommand struct {
 	ViceroyVersioner        github.AssetVersioner
 
 	// Serve private fields
-	addr                 string
-	debug                bool
-	enablePushpin        bool
-	pushpinRunnerBinPath string
-	pushpinProxyPort     string
-	pushpinPublishPort   string
-	env                  argparser.OptionalString
-	file                 argparser.OptionalString
-	profileGuest         bool
-	profileGuestDir      argparser.OptionalString
-	projectDir           string
-	skipBuild            bool
-	watch                bool
-	watchDir             argparser.OptionalString
+	addr                        string
+	debug                       bool
+	enablePushpin               bool
+	enableWebsocketsPassthrough argparser.OptionalBool
+	pushpinRunnerBinPath        string
+	pushpinProxyPort            string
+	pushpinPublishPort          string
+	env                         argparser.OptionalString
+	file                        argparser.OptionalString
+	profileGuest                bool
+	profileGuestDir             argparser.OptionalString
+	projectDir                  string
+	skipBuild                   bool
+	watch                       bool
+	watchDir                    argparser.OptionalString
 }
 
 // NewServeCommand returns a usable command registered under the parent.
@@ -102,6 +103,7 @@ func NewServeCommand(parent argparser.Registerer, g *global.Data, build *BuildCo
 	c.CmdClause.Flag("pushpin-path", "The path to a user installed version of the Pushpin runner binary").StringVar(&c.pushpinRunnerBinPath)
 	c.CmdClause.Flag("pushpin-proxy-port", "The port to run the Pushpin runner on. Overrides 'local_server.pushpin.proxy_port' from 'fastly.toml', and if not specified there, defaults to 7677.").StringVar(&c.pushpinProxyPort)
 	c.CmdClause.Flag("pushpin-publish-port", "The port to run the Pushpin publish handler on. Overrides 'local_server.pushpin.publish_port' from 'fastly.toml', and if not specified there, defaults to 5561.").StringVar(&c.pushpinPublishPort)
+	c.CmdClause.Flag("experimental-websockets-passthrough", "Enable WebSocket passthrough support for local testing of WebSockets. Overrides 'local_server.websockets_passthrough.enable' from 'fastly.toml', and if not specified there, defaults to true.").Action(c.enableWebsocketsPassthrough.Set).BoolVar(&c.enableWebsocketsPassthrough.Value)
 	c.CmdClause.Flag("profile-guest", "Profile the Wasm guest under Viceroy (requires Viceroy 0.9.1 or higher). View profiles at https://profiler.firefox.com/.").BoolVar(&c.profileGuest)
 	c.CmdClause.Flag("profile-guest-dir", "The directory where the per-request profiles are saved to. Defaults to guest-profiles.").Action(c.profileGuestDir.Set).StringVar(&c.profileGuestDir.Value)
 	c.CmdClause.Flag("skip-build", "Skip the build step").BoolVar(&c.skipBuild)
@@ -223,6 +225,19 @@ func (c *ServeCommand) Exec(in io.Reader, out io.Writer) (err error) {
 		defer pushpinCtx.Close()
 	}
 
+	// WebSocket passthrough is enabled unless it's explicitly disabled via the
+	// --experimental-websockets-passthrough flag, or via
+	// `local_server.websockets_passthrough.enable` in fastly.toml. The flag
+	// takes precedence over the manifest.
+	enableWebsocketsPassthrough := true
+	switch {
+	case c.enableWebsocketsPassthrough.WasSet:
+		enableWebsocketsPassthrough = c.enableWebsocketsPassthrough.Value
+	case c.Globals.Manifest.File.LocalServer.WebsocketsPassthrough != nil &&
+		c.Globals.Manifest.File.LocalServer.WebsocketsPassthrough.EnableWebsocketsPassthrough != nil:
+		enableWebsocketsPassthrough = *c.Globals.Manifest.File.LocalServer.WebsocketsPassthrough.EnableWebsocketsPassthrough
+	}
+
 	err = spinner.Start()
 	if err != nil {
 		return err
@@ -243,21 +258,22 @@ func (c *ServeCommand) Exec(in io.Reader, out io.Writer) (err error) {
 	var restart bool
 	for {
 		err = local(localOpts{
-			addr:             c.addr,
-			bin:              bin,
-			debug:            c.debug,
-			errLog:           c.Globals.ErrLog,
-			extraArgs:        c.ViceroyBinExtraArgs,
-			manifestPath:     manifestPath,
-			out:              out,
-			profileGuest:     c.profileGuest,
-			profileGuestDir:  c.profileGuestDir,
-			pushpinProxyPort: pushpinCtx.proxyPort,
-			restarted:        restart,
-			verbose:          c.Globals.Verbose(),
-			wasmBinPath:      wasmBinaryToRun,
-			watch:            c.watch,
-			watchDir:         c.watchDir,
+			addr:                        c.addr,
+			bin:                         bin,
+			debug:                       c.debug,
+			enableWebsocketsPassthrough: enableWebsocketsPassthrough,
+			errLog:                      c.Globals.ErrLog,
+			extraArgs:                   c.ViceroyBinExtraArgs,
+			manifestPath:                manifestPath,
+			out:                         out,
+			profileGuest:                c.profileGuest,
+			profileGuestDir:             c.profileGuestDir,
+			pushpinProxyPort:            pushpinCtx.proxyPort,
+			restarted:                   restart,
+			verbose:                     c.Globals.Verbose(),
+			wasmBinPath:                 wasmBinaryToRun,
+			watch:                       c.watch,
+			watchDir:                    c.watchDir,
 		})
 		if err != nil {
 			if err != fsterr.ErrViceroyRestart {
@@ -820,21 +836,22 @@ func (c *ServeCommand) startPushpin(spinner text.Spinner, out io.Writer) (pushpi
 
 // localOpts represents the inputs for `local()`.
 type localOpts struct {
-	addr             string
-	bin              string
-	debug            bool
-	errLog           fsterr.LogInterface
-	extraArgs        string
-	manifestPath     string
-	out              io.Writer
-	profileGuest     bool
-	profileGuestDir  argparser.OptionalString
-	pushpinProxyPort uint16
-	restarted        bool
-	verbose          bool
-	wasmBinPath      string
-	watch            bool
-	watchDir         argparser.OptionalString
+	addr                        string
+	bin                         string
+	debug                       bool
+	enableWebsocketsPassthrough bool
+	errLog                      fsterr.LogInterface
+	extraArgs                   string
+	manifestPath                string
+	out                         io.Writer
+	profileGuest                bool
+	profileGuestDir             argparser.OptionalString
+	pushpinProxyPort            uint16
+	restarted                   bool
+	verbose                     bool
+	wasmBinPath                 string
+	watch                       bool
+	watchDir                    argparser.OptionalString
 }
 
 // local spawns a subprocess that runs the compiled binary.
@@ -863,6 +880,12 @@ func local(opts localOpts) error {
 		args = append(args, fmt.Sprintf("--local-pushpin-proxy-port=%d", opts.pushpinProxyPort))
 	}
 
+	// Viceroy enables WebSocket passthrough by default, so we only need to pass
+	// the flag when it has been explicitly disabled in the manifest.
+	if !opts.enableWebsocketsPassthrough {
+		args = append(args, "--enable-local-websocket-passthrough=false")
+	}
+
 	if opts.extraArgs != "" {
 		extraArgs := strings.Split(opts.extraArgs, " ")
 		args = append(args, extraArgs...)

pkg/manifest/file.go

@@ -109,6 +109,14 @@ func (f *File) MarshalTOML() ([]byte, error) {
 		localServer["pushpin"] = pushpin
 	}
 
+	if f.LocalServer.WebsocketsPassthrough != nil {
+		websocketsPassthrough := make(map[string]any)
+		if f.LocalServer.WebsocketsPassthrough.EnableWebsocketsPassthrough != nil {
+			websocketsPassthrough["enable"] = *f.LocalServer.WebsocketsPassthrough.EnableWebsocketsPassthrough
+		}
+		localServer["websockets_passthrough"] = websocketsPassthrough
+	}
+
 	if f.LocalServer.SecretStores != nil {
 		secretStores := make(map[string]any)
 		for key, entry := range f.LocalServer.SecretStores {

pkg/manifest/local_server.go

@@ -9,12 +9,13 @@ import (
 
 // LocalServer represents a list of mocked Viceroy resources.
 type LocalServer struct {
-	Backends       map[string]LocalBackend     `toml:"backends"`
-	ConfigStores   map[string]LocalConfigStore `toml:"config_stores,omitempty"`
-	KVStores       LocalKVStoreMap             `toml:"kv_stores,omitempty"`
-	SecretStores   LocalSecretStoreMap         `toml:"secret_stores,omitempty"`
-	Pushpin        *LocalPushpinMap            `toml:"pushpin,omitempty"`
-	ViceroyVersion string                      `toml:"viceroy_version,omitempty"`
+	Backends              map[string]LocalBackend        `toml:"backends"`
+	ConfigStores          map[string]LocalConfigStore    `toml:"config_stores,omitempty"`
+	KVStores              LocalKVStoreMap                `toml:"kv_stores,omitempty"`
+	SecretStores          LocalSecretStoreMap            `toml:"secret_stores,omitempty"`
+	Pushpin               *LocalPushpinMap               `toml:"pushpin,omitempty"`
+	WebsocketsPassthrough *LocalWebsocketsPassthroughMap `toml:"websockets_passthrough,omitempty"`
+	ViceroyVersion        string                         `toml:"viceroy_version,omitempty"`
 }
 
 // LocalBackend represents a backend to be mocked by the local testing server.
@@ -203,6 +204,12 @@ type LocalPushpinMap struct {
 	PushpinPublishPort *uint16 `toml:"publish_port,omitempty"`
 }
 
+// LocalWebsocketsPassthroughMap represents configuration of local WebSocket
+// passthrough support, used for local testing of handoff_websocket.
+type LocalWebsocketsPassthroughMap struct {
+	EnableWebsocketsPassthrough *bool `toml:"enable,omitempty"`
+}
+
 func decodeTOMLMap(m map[string]any, out any) error {
 	buf := new(bytes.Buffer)
 	enc := toml.NewEncoder(buf)

pkg/manifest/testdata/fastly-viceroy-update.toml

@@ -57,6 +57,9 @@ pushpin_path = "path/to/pushpin"
 proxy_port = 7777
 publish_port = 6666
 
+[local_server.websockets_passthrough]
+enable = false
+
 [local_server.secret_stores]
 store_one = [
   { key = "first", data = "This is some secret data" },