chore: add experiment toggle for terraform workspace caching (#20559)

Emyrk · web-flow · commit 04727c06e8ed · 2025-11-12T14:26:15.000-06:00
Experiments passed to provisioners to determine behavior. This adds
`--experiments` flag to provisioner daemons. Prior to this, provisioners
had no method to turn on/off experiments.
diff --git a/cli/server.go b/cli/server.go
@@ -1476,6 +1476,7 @@ func newProvisionerDaemon(
 						Listener:      terraformServer,
 						Logger:        provisionerLogger,
 						WorkDirectory: workDir,
+						Experiments:   coderAPI.Experiments,
 					},
 					CachePath: tfDir,
 					Tracer:    tracer,
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
@@ -1999,6 +1999,7 @@ func (api *API) CreateInMemoryTaggedProvisionerDaemon(dialCtx context.Context, n
 		api.NotificationsEnqueuer,
 		&api.PrebuildsReconciler,
 		api.ProvisionerdServerMetrics,
+		api.Experiments,
 	)
 	if err != nil {
 		return nil, err
diff --git a/coderd/provisionerdserver/provisionerdserver.go b/coderd/provisionerdserver/provisionerdserver.go
@@ -121,6 +121,7 @@ type server struct {
 	NotificationsEnqueuer       notifications.Enqueuer
 	PrebuildsOrchestrator       *atomic.Pointer[prebuilds.ReconciliationOrchestrator]
 	UsageInserter               *atomic.Pointer[usage.Inserter]
+	Experiments                 codersdk.Experiments
 
 	OIDCConfig promoauth.OAuth2Config
 
@@ -182,6 +183,7 @@ func NewServer(
 	enqueuer notifications.Enqueuer,
 	prebuildsOrchestrator *atomic.Pointer[prebuilds.ReconciliationOrchestrator],
 	metrics *Metrics,
+	experiments codersdk.Experiments,
 ) (proto.DRPCProvisionerDaemonServer, error) {
 	// Fail-fast if pointers are nil
 	if lifecycleCtx == nil {
@@ -253,6 +255,7 @@ func NewServer(
 		PrebuildsOrchestrator:       prebuildsOrchestrator,
 		UsageInserter:               usageInserter,
 		metrics:                     metrics,
+		Experiments:                 experiments,
 	}
 
 	if s.heartbeatFn == nil {
diff --git a/coderd/provisionerdserver/provisionerdserver_test.go b/coderd/provisionerdserver/provisionerdserver_test.go
@@ -26,6 +26,7 @@ import (
 	"storj.io/drpc"
 
 	"cdr.dev/slog/sloggers/slogtest"
+	"github.com/coder/coder/v2/coderd"
 	"github.com/coder/coder/v2/coderd/util/ptr"
 	"github.com/coder/quartz"
 	"github.com/coder/serpent"
@@ -4162,7 +4163,7 @@ func setup(t *testing.T, ignoreLogErrors bool, ov *overrides) (proto.DRPCProvisi
 	defOrg, err := db.GetDefaultOrganization(context.Background())
 	require.NoError(t, err, "default org not found")
 
-	deploymentValues := &codersdk.DeploymentValues{}
+	deploymentValues := coderdtest.DeploymentValues(t)
 	var externalAuthConfigs []*externalauth.Config
 	tss := testTemplateScheduleStore()
 	uqhss := testUserQuietHoursScheduleStore()
@@ -4285,6 +4286,7 @@ func setup(t *testing.T, ignoreLogErrors bool, ov *overrides) (proto.DRPCProvisi
 		notifEnq,
 		&op,
 		provisionerdserver.NewMetrics(logger),
+		coderd.ReadExperiments(logger, deploymentValues.Experiments),
 	)
 	require.NoError(t, err)
 	return srv, db, ps, daemon
diff --git a/codersdk/deployment.go b/codersdk/deployment.go
@@ -3646,6 +3646,8 @@ const (
 	ExperimentOAuth2             Experiment = "oauth2"               // Enables OAuth2 provider functionality.
 	ExperimentMCPServerHTTP      Experiment = "mcp-server-http"      // Enables the MCP HTTP server functionality.
 	ExperimentWorkspaceSharing   Experiment = "workspace-sharing"    // Enables updating workspace ACLs for sharing with users and groups.
+	// ExperimentTerraformWorkspace uses the "Terraform Workspaces" feature, not to be confused with Coder Workspaces.
+	ExperimentTerraformWorkspace Experiment = "terraform-directory-reuse" // Enables reuse of existing terraform directory for builds
 )
 
 func (e Experiment) DisplayName() string {
@@ -3666,6 +3668,8 @@ func (e Experiment) DisplayName() string {
 		return "MCP HTTP Server Functionality"
 	case ExperimentWorkspaceSharing:
 		return "Workspace Sharing"
+	case ExperimentTerraformWorkspace:
+		return "Terraform Directory Reuse"
 	default:
 		// Split on hyphen and convert to title case
 		// e.g. "web-push" -> "Web Push", "mcp-server-http" -> "Mcp Server Http"
diff --git a/docs/reference/api/schemas.md b/docs/reference/api/schemas.md
diff --git a/docs/reference/cli/provisioner_start.md b/docs/reference/cli/provisioner_start.md
diff --git a/enterprise/cli/provisionerdaemonstart.go b/enterprise/cli/provisionerdaemonstart.go
@@ -23,6 +23,7 @@ import (
 	"github.com/coder/coder/v2/cli/clilog"
 	"github.com/coder/coder/v2/cli/cliui"
 	"github.com/coder/coder/v2/cli/cliutil"
+	"github.com/coder/coder/v2/coderd"
 	"github.com/coder/coder/v2/coderd/database"
 	"github.com/coder/coder/v2/codersdk"
 	"github.com/coder/coder/v2/codersdk/drpcsdk"
@@ -48,6 +49,7 @@ func (r *RootCmd) provisionerDaemonStart() *serpent.Command {
 		preSharedKey   string
 		provisionerKey string
 		verbose        bool
+		experiments    []string
 
 		prometheusEnable  bool
 		prometheusAddress string
@@ -186,6 +188,7 @@ func (r *RootCmd) provisionerDaemonStart() *serpent.Command {
 						Listener:      terraformServer,
 						Logger:        logger.Named("terraform"),
 						WorkDirectory: tempDir,
+						Experiments:   coderd.ReadExperiments(logger, experiments),
 					},
 					CachePath: cacheDir,
 				})
@@ -378,6 +381,14 @@ func (r *RootCmd) provisionerDaemonStart() *serpent.Command {
 			Value:       serpent.StringOf(&prometheusAddress),
 			Default:     "127.0.0.1:2112",
 		},
+		{
+			Name:        "Experiments",
+			Description: "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",
+			Env:         "CODER_EXPERIMENTS",
+			Value:       serpent.StringArrayOf(&experiments),
+			YAML:        "experiments",
+		},
 	}
 	orgContext.AttachOptions(cmd)
 
diff --git a/enterprise/cli/testdata/coder_provisioner_start_--help.golden b/enterprise/cli/testdata/coder_provisioner_start_--help.golden
@@ -6,6 +6,11 @@ USAGE:
   Run a provisioner daemon
 
 OPTIONS:
+      --experiments string-array, $CODER_EXPERIMENTS
+          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.
+
   -O, --org string, $CODER_ORGANIZATION
           Select which organization (uuid or name) to use.
 
diff --git a/enterprise/coderd/coderdenttest/coderdenttest.go b/enterprise/coderd/coderdenttest/coderdenttest.go
@@ -414,6 +414,7 @@ func newExternalProvisionerDaemon(t testing.TB, client *codersdk.Client, org uui
 				ServeOptions: &provisionersdk.ServeOptions{
 					Listener:      provisionerSrv,
 					WorkDirectory: t.TempDir(),
+					Experiments:   codersdk.Experiments{},
 				},
 			}))
 		}()
diff --git a/enterprise/coderd/provisionerdaemons.go b/enterprise/coderd/provisionerdaemons.go
@@ -362,6 +362,7 @@ func (api *API) provisionerDaemonServe(rw http.ResponseWriter, r *http.Request)
 		api.NotificationsEnqueuer,
 		&api.AGPL.PrebuildsReconciler,
 		api.ProvisionerdServerMetrics,
+		api.AGPL.Experiments,
 	)
 	if err != nil {
 		if !xerrors.Is(err, context.Canceled) {
diff --git a/provisionersdk/serve.go b/provisionersdk/serve.go
@@ -15,6 +15,7 @@ import (
 	"storj.io/drpc/drpcserver"
 
 	"cdr.dev/slog"
+	"github.com/coder/coder/v2/codersdk"
 	"github.com/coder/coder/v2/codersdk/drpcsdk"
 
 	"github.com/coder/coder/v2/coderd/tracing"
@@ -30,6 +31,7 @@ type ServeOptions struct {
 	Logger              slog.Logger
 	WorkDirectory       string
 	ExternalProvisioner bool
+	Experiments         codersdk.Experiments
 }
 
 type Server interface {
diff --git a/site/src/api/typesGenerated.ts b/site/src/api/typesGenerated.ts

Original file line number	Diff line number	Diff line change
`@@ -1999,6 +1999,7 @@ func (api *API) CreateInMemoryTaggedProvisionerDaemon(dialCtx context.Context, n`
`1999`	`1999`	`api.NotificationsEnqueuer,`
`2000`	`2000`	`&api.PrebuildsReconciler,`
`2001`	`2001`	`api.ProvisionerdServerMetrics,`
	`2002`	`+ api.Experiments,`
`2002`	`2003`	`)`
`2003`	`2004`	`if err != nil {`
`2004`	`2005`	`return nil, err`