chore: allow terraform & echo built-in provisioners (#13121)

* chore: allow terraform & echo built-in provisioners

Built-in provisioners serve all specified types. This allows running terraform, echo, or both in built in.
The cli flag to control the types is hidden by default, to be used primarily for testing purposes.

cli/server.go

@@ -944,6 +944,13 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 			var provisionerdWaitGroup sync.WaitGroup
 			defer provisionerdWaitGroup.Wait()
 			provisionerdMetrics := provisionerd.NewMetrics(options.PrometheusRegistry)
+
+			// Built in provisioner daemons will support the same types.
+			// By default, this is the slice {"terraform"}
+			provisionerTypes := make([]codersdk.ProvisionerType, 0)
+			for _, pt := range vals.Provisioner.DaemonTypes {
+				provisionerTypes = append(provisionerTypes, codersdk.ProvisionerType(pt))
+			}
 			for i := int64(0); i < vals.Provisioner.Daemons.Value(); i++ {
 				suffix := fmt.Sprintf("%d", i)
 				// The suffix is added to the hostname, so we may need to trim to fit into
@@ -952,7 +959,7 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 				name := fmt.Sprintf("%s-%s", hostname, suffix)
 				daemonCacheDir := filepath.Join(cacheDir, fmt.Sprintf("provisioner-%d", i))
 				daemon, err := newProvisionerDaemon(
-					ctx, coderAPI, provisionerdMetrics, logger, vals, daemonCacheDir, errCh, &provisionerdWaitGroup, name,
+					ctx, coderAPI, provisionerdMetrics, logger, vals, daemonCacheDir, errCh, &provisionerdWaitGroup, name, provisionerTypes,
 				)
 				if err != nil {
 					return xerrors.Errorf("create provisioner daemon: %w", err)
@@ -1340,6 +1347,7 @@ func newProvisionerDaemon(
 	errCh chan error,
 	wg *sync.WaitGroup,
 	name string,
+	provisionerTypes []codersdk.ProvisionerType,
 ) (srv *provisionerd.Server, err error) {
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -1359,79 +1367,88 @@ func newProvisionerDaemon(
 		return nil, xerrors.Errorf("mkdir work dir: %w", err)
 	}
 
+	// Omit any duplicates
+	provisionerTypes = slice.Unique(provisionerTypes)
+
+	// Populate the connector with the supported types.
 	connector := provisionerd.LocalProvisioners{}
-	if cfg.Provisioner.DaemonsEcho {
-		echoClient, echoServer := drpc.MemTransportPipe()
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			<-ctx.Done()
-			_ = echoClient.Close()
-			_ = echoServer.Close()
-		}()
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			defer cancel()
+	for _, provisionerType := range provisionerTypes {
+		switch provisionerType {
+		case codersdk.ProvisionerTypeEcho:
+			echoClient, echoServer := drpc.MemTransportPipe()
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				<-ctx.Done()
+				_ = echoClient.Close()
+				_ = echoServer.Close()
+			}()
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				defer cancel()
 
-			err := echo.Serve(ctx, &provisionersdk.ServeOptions{
-				Listener:      echoServer,
-				WorkDirectory: workDir,
-				Logger:        logger.Named("echo"),
-			})
-			if err != nil {
-				select {
-				case errCh <- err:
-				default:
-				}
-			}
-		}()
-		connector[string(database.ProvisionerTypeEcho)] = sdkproto.NewDRPCProvisionerClient(echoClient)
-	} else {
-		tfDir := filepath.Join(cacheDir, "tf")
-		err = os.MkdirAll(tfDir, 0o700)
-		if err != nil {
-			return nil, xerrors.Errorf("mkdir terraform dir: %w", err)
-		}
-
-		tracer := coderAPI.TracerProvider.Tracer(tracing.TracerName)
-		terraformClient, terraformServer := drpc.MemTransportPipe()
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			<-ctx.Done()
-			_ = terraformClient.Close()
-			_ = terraformServer.Close()
-		}()
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			defer cancel()
-
-			err := terraform.Serve(ctx, &terraform.ServeOptions{
-				ServeOptions: &provisionersdk.ServeOptions{
-					Listener:      terraformServer,
-					Logger:        logger.Named("terraform"),
+				err := echo.Serve(ctx, &provisionersdk.ServeOptions{
+					Listener:      echoServer,
 					WorkDirectory: workDir,
-				},
-				CachePath: tfDir,
-				Tracer:    tracer,
-			})
-			if err != nil && !xerrors.Is(err, context.Canceled) {
-				select {
-				case errCh <- err:
-				default:
+					Logger:        logger.Named("echo"),
+				})
+				if err != nil {
+					select {
+					case errCh <- err:
+					default:
+					}
 				}
+			}()
+			connector[string(database.ProvisionerTypeEcho)] = sdkproto.NewDRPCProvisionerClient(echoClient)
+		case codersdk.ProvisionerTypeTerraform:
+			tfDir := filepath.Join(cacheDir, "tf")
+			err = os.MkdirAll(tfDir, 0o700)
+			if err != nil {
+				return nil, xerrors.Errorf("mkdir terraform dir: %w", err)
 			}
-		}()
 
-		connector[string(database.ProvisionerTypeTerraform)] = sdkproto.NewDRPCProvisionerClient(terraformClient)
+			tracer := coderAPI.TracerProvider.Tracer(tracing.TracerName)
+			terraformClient, terraformServer := drpc.MemTransportPipe()
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				<-ctx.Done()
+				_ = terraformClient.Close()
+				_ = terraformServer.Close()
+			}()
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				defer cancel()
+
+				err := terraform.Serve(ctx, &terraform.ServeOptions{
+					ServeOptions: &provisionersdk.ServeOptions{
+						Listener:      terraformServer,
+						Logger:        logger.Named("terraform"),
+						WorkDirectory: workDir,
+					},
+					CachePath: tfDir,
+					Tracer:    tracer,
+				})
+				if err != nil && !xerrors.Is(err, context.Canceled) {
+					select {
+					case errCh <- err:
+					default:
+					}
+				}
+			}()
+
+			connector[string(database.ProvisionerTypeTerraform)] = sdkproto.NewDRPCProvisionerClient(terraformClient)
+		default:
+			return nil, fmt.Errorf("unknown provisioner type %q", provisionerType)
+		}
 	}
 
 	return provisionerd.New(func(dialCtx context.Context) (proto.DRPCProvisionerDaemonClient, error) {
 		// This debounces calls to listen every second. Read the comment
 		// in provisionerdserver.go to learn more!
-		return coderAPI.CreateInMemoryProvisionerDaemon(dialCtx, name)
+		return coderAPI.CreateInMemoryProvisionerDaemon(dialCtx, name, provisionerTypes)
 	}, &provisionerd.Options{
 		Logger:              logger.Named(fmt.Sprintf("provisionerd-%s", name)),
 		UpdateInterval:      time.Second,