coder · johnstcn · Jan 18, 2023 · Jan 16, 2023 · Jan 18, 2023 · Jan 18, 2023
diff --git a/cli/deployment/config.go b/cli/deployment/config.go
@@ -446,10 +446,19 @@ func newConfig() *codersdk.DeploymentConfig {
 				Default:     512,
 			},
 		},
+		// DEPRECATED: use Experiments instead.
 		Experimental: &codersdk.DeploymentConfigField[bool]{
-			Name:  "Experimental",
-			Usage: "Enable experimental features. Experimental features are not ready for production.",
-			Flag:  "experimental",
+			Name:    "Experimental",
+			Usage:   "Enable experimental features. Experimental features are not ready for production.",
+			Flag:    "experimental",
+			Default: false,
+			Hidden:  true,
+		},
+		Experiments: &codersdk.DeploymentConfigField[[]string]{
+			Name:    "Experiments",
+			Usage:   "Enable one or more experiments. These are not ready for production. Separate multiple experiments with commas, or enter '*' to opt-in to all available experiments.",
+			Flag:    "experiments",
+			Default: []string{},
 		},
 		UpdateCheck: &codersdk.DeploymentConfigField[bool]{
 			Name:    "Update Check",
@@ -557,12 +566,12 @@ func setConfig(prefix string, vip *viper.Viper, target interface{}) {
 			// with a comma, but Viper only supports with a space. This
 			// is a small hack around it!
 			rawSlice := reflect.ValueOf(vip.GetStringSlice(prefix)).Interface()
-			slice, ok := rawSlice.([]string)
+			stringSlice, ok := rawSlice.([]string)
 			if !ok {
 				panic(fmt.Sprintf("string slice is of type %T", rawSlice))
 			}
-			value := make([]string, 0, len(slice))
-			for _, entry := range slice {
+			value := make([]string, 0, len(stringSlice))
+			for _, entry := range stringSlice {
 				value = append(value, strings.Split(entry, ",")...)
 			}
 			val.FieldByName("Value").Set(reflect.ValueOf(value))

diff --git a/cli/deployment/config_test.go b/cli/deployment/config_test.go
@@ -232,6 +232,23 @@ func TestConfig(t *testing.T) {
 			require.Equal(t, config.Prometheus.Enable.Value, true)
 			require.Equal(t, config.Prometheus.Address.Value, config.Prometheus.Address.Default)
 		},
+	}, {
+		Name: "Experiments - no features",
+		Env: map[string]string{
+			"CODER_EXPERIMENTS": "",
+		},
+		Valid: func(config *codersdk.DeploymentConfig) {
+			require.Empty(t, config.Experiments.Value)
+		},
+	}, {
+		Name: "Experiments - multiple features",
+		Env: map[string]string{
+			"CODER_EXPERIMENTS": "foo,bar",
+		},
+		Valid: func(config *codersdk.DeploymentConfig) {
+			expected := []string{"foo", "bar"}
+			require.ElementsMatch(t, expected, config.Experiments.Value)
+		},
 	}} {
 		tc := tc
 		t.Run(tc.Name, func(t *testing.T) {

diff --git a/cli/testdata/coder_server_--help.golden b/cli/testdata/coder_server_--help.golden
@@ -61,10 +61,12 @@ Flags:
                                                      Consumes
                                                      $CODER_DERP_SERVER_STUN_ADDRESSES
                                                      (default [stun.l.google.com:19302])
-      --experimental                                 Enable experimental features.
-                                                     Experimental features are not ready for
-                                                     production.
-                                                     Consumes $CODER_EXPERIMENTAL
+      --experiments strings                          Enable one or more experiments. These are
+                                                     not ready for production. Separate
+                                                     multiple experiments with commas, or
+                                                     enter '*' to opt-in to all available
+                                                     experiments.
+                                                     Consumes $CODER_EXPERIMENTS
   -h, --help                                         help for server
       --http-address string                          HTTP bind address of the server. Unset to
                                                      disable the HTTP endpoint.

diff --git a/coderd/apidoc/docs.go b/coderd/apidoc/docs.go
diff --git a/coderd/apidoc/swagger.json b/coderd/apidoc/swagger.json
diff --git a/coderd/coderd.go b/coderd/coderd.go
@@ -52,6 +52,7 @@ import (
 	"github.com/coder/coder/coderd/telemetry"
 	"github.com/coder/coder/coderd/tracing"
 	"github.com/coder/coder/coderd/updatecheck"
+	"github.com/coder/coder/coderd/util/slice"
 	"github.com/coder/coder/coderd/wsconncache"
 	"github.com/coder/coder/codersdk"
 	"github.com/coder/coder/provisionerd/proto"
@@ -220,6 +221,7 @@ func New(options *Options) *API {
 		},
 		metricsCache: metricsCache,
 		Auditor:      atomic.Pointer[audit.Auditor]{},
+		Experiments:  initExperiments(options.Logger, options.DeploymentConfig.Experiments.Value, options.DeploymentConfig.Experimental.Value),
 	}
 	if options.UpdateCheckOptions != nil {
 		api.updateChecker = updatecheck.New(
@@ -348,6 +350,10 @@ func New(options *Options) *API {
 		r.Post("/csp/reports", api.logReportCSPViolations)
 
 		r.Get("/buildinfo", buildInfo)
+		r.Route("/experiments", func(r chi.Router) {
+			r.Use(apiKeyMiddleware)
+			r.Get("/", api.handleExperimentsGet)
+		})
 		r.Get("/updatecheck", api.updateCheck)
 		r.Route("/config", func(r chi.Router) {
 			r.Use(apiKeyMiddleware)
@@ -646,6 +652,10 @@ type API struct {
 	metricsCache        *metricscache.Cache
 	workspaceAgentCache *wsconncache.Cache
 	updateChecker       *updatecheck.Checker
+
+	// Experiments contains the list of experiments currently enabled.
+	// This is used to gate features that are not yet ready for production.
+	Experiments codersdk.Experiments
 }
 
 // Close waits for all WebSocket connections to drain before returning.
@@ -752,3 +762,27 @@ func (api *API) CreateInMemoryProvisionerDaemon(ctx context.Context, debounce ti
 
 	return proto.NewDRPCProvisionerDaemonClient(clientSession), nil
 }
+
+// nolint:revive
+func initExperiments(log slog.Logger, raw []string, legacyAll bool) codersdk.Experiments {
+	exps := make([]codersdk.Experiment, 0, len(raw))
+	for _, v := range raw {
+		switch v {
+		case "*":
+			exps = append(exps, codersdk.ExperimentsAll...)
+		default:
+			ex := codersdk.Experiment(v)
+			if !slice.Contains(codersdk.ExperimentsAll, ex) {
+				log.Warn(context.Background(), "🐉 HERE BE DRAGONS: opting into hidden experiment", slog.F("experiment", ex))
+			}
+			exps = append(exps, ex)
+		}
+	}
+
+	// --experiments takes precedence over --experimental. It's deprecated.
+	if legacyAll && len(raw) == 0 {
+		log.Warn(context.Background(), "--experimental is deprecated, use --experiments='*' instead")
+		exps = append(exps, codersdk.ExperimentsAll...)
+	}
+	return exps
+}
diff --git a/coderd/coderdtest/authorize.go b/coderd/coderdtest/authorize.go
@@ -48,6 +48,7 @@ func AGPLRoutes(a *AuthTester) (map[string]string, map[string]RouteCheck) {
 		"GET:/healthz":                  {NoAuthorize: true},
 		"GET:/api/v2":                   {NoAuthorize: true},
 		"GET:/api/v2/buildinfo":         {NoAuthorize: true},
+		"GET:/api/v2/experiments":       {NoAuthorize: true}, // This route requires AuthN, but not AuthZ.
 		"GET:/api/v2/updatecheck":       {NoAuthorize: true},
 		"GET:/api/v2/users/first":       {NoAuthorize: true},
 		"POST:/api/v2/users/first":      {NoAuthorize: true},

diff --git a/coderd/coderdtest/coderdtest.go b/coderd/coderdtest/coderdtest.go
@@ -85,7 +85,6 @@ type Options struct {
 	AppHostname          string
 	AWSCertificates      awsidentity.Certificates
 	Authorizer           rbac.Authorizer
-	Experimental         bool
 	AzureCertificates    x509.VerifyOptions
 	GithubOAuth2Config   *coderd.GithubOAuth2Config
 	RealIPConfig         *httpmw.RealIPConfig

diff --git a/coderd/experiments.go b/coderd/experiments.go
@@ -0,0 +1,19 @@
+package coderd
+
+import (
+	"net/http"
+
+	"github.com/coder/coder/coderd/httpapi"
+)
+
+// @Summary Get experiments
+// @ID get-experiments
+// @Security CoderSessionToken
+// @Produce json
+// @Tags General
+// @Success 200 {array} codersdk.Experiment
+// @Router /experiments [get]
+func (api *API) handleExperimentsGet(rw http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	httpapi.Write(ctx, rw, http.StatusOK, api.Experiments)
+}