fix: language plugin logs have named scope and are parsed as json

frontend/cli/cmd_new.go

@@ -69,7 +69,7 @@ func prepareNewCmd(ctx context.Context, k *kong.Kong, args []string) (optionalPl
 		return optionalPlugin, fmt.Errorf("could not create bind allocator: %w", err)
 	}
 
-	plugin, err := languageplugin.New(ctx, bindAllocator, language)
+	plugin, err := languageplugin.New(ctx, bindAllocator, language, "new")
 	if err != nil {
 		return optionalPlugin, fmt.Errorf("could not create plugin for %v: %w", language, err)
 	}

internal/buildengine/engine.go

@@ -1028,7 +1028,7 @@ func (e *Engine) gatherSchemas(
 }
 
 func (e *Engine) newModuleMeta(ctx context.Context, config moduleconfig.UnvalidatedModuleConfig) (moduleMeta, error) {
-	plugin, err := languageplugin.New(ctx, e.bindAllocator, config.Language)
+	plugin, err := languageplugin.New(ctx, e.bindAllocator, config.Language, config.Module)
 	if err != nil {
 		return moduleMeta{}, fmt.Errorf("could not create plugin for %s: %w", config.Module, err)
 	}

internal/buildengine/languageplugin/external_integration_test.go

@@ -244,7 +244,7 @@ func startPlugin() in.Action {
 
 		bindURL, err = bindAllocator.Next()
 		assert.NoError(t, err)
-		client, err = newExternalPluginImpl(ic.Context, bindURL, ic.Language)
+		client, err = newExternalPluginImpl(ic.Context, bindURL, ic.Language, "test")
 		assert.NoError(t, err)
 	}
 }

internal/buildengine/languageplugin/external_plugin.go

@@ -49,8 +49,8 @@ type externalPlugin struct {
 
 var _ LanguagePlugin = &externalPlugin{}
 
-func newExternalPlugin(ctx context.Context, bind *url.URL, language string) (*externalPlugin, error) {
-	impl, err := newExternalPluginImpl(ctx, bind, language)
+func newExternalPlugin(ctx context.Context, bind *url.URL, language, name string) (*externalPlugin, error) {
+	impl, err := newExternalPluginImpl(ctx, bind, language, name)
 	if err != nil {
 		return nil, err
 	}

internal/buildengine/languageplugin/external_plugin_client.go

@@ -45,35 +45,50 @@ type externalPluginImpl struct {
 	cmdError chan error
 }
 
-func newExternalPluginImpl(ctx context.Context, bind *url.URL, language string) (*externalPluginImpl, error) {
+func newExternalPluginImpl(ctx context.Context, bind *url.URL, language, name string) (*externalPluginImpl, error) {
 	impl := &externalPluginImpl{
 		client: rpc.Dial(langconnect.NewLanguageServiceClient, bind.String(), log.Error),
 	}
-	err := impl.start(ctx, bind, language)
+	err := impl.start(ctx, bind, language, name)
 	if err != nil {
 		return nil, err
 	}
 	return impl, nil
 }
 
 // Start launches the plugin and blocks until the plugin is ready.
-func (p *externalPluginImpl) start(ctx context.Context, bind *url.URL, language string) error {
+func (p *externalPluginImpl) start(ctx context.Context, bind *url.URL, language, name string) error {
+	logger := log.FromContext(ctx).Scope(name)
+
 	cmdName := "ftl-language-" + language
 	p.cmd = exec.Command(ctx, log.Debug, ".", cmdName, "--bind", bind.String())
+	p.cmd.Env = append(p.cmd.Env, "FTL_NAME="+name)
 	_, err := exec.LookPath(cmdName)
 	if err != nil {
 		return fmt.Errorf("failed to find plugin for %s: %w", language, err)
 	}
 
+	// Send the plugin's stderr to the logger.
+	p.cmd.Stderr = nil
+	pipe, err := p.cmd.StderrPipe()
+	if err != nil {
+		return fmt.Errorf("could not create stderr pipe for %s: %w", name, err)
+	}
+	go func() {
+		err := log.JSONStreamer(pipe, logger, log.Error)
+		if err != nil {
+			logger.Errorf(err, "Error streaming plugin logs.")
+		}
+	}()
+
 	runCtx, cancel := context.WithCancel(ctx)
 
 	p.cmdError = make(chan error)
 	pingErr := make(chan error)
 
 	// run the plugin and wait for it to finish executing
 	go func() {
-		err := p.cmd.RunBuffered(runCtx)
-		fmt.Printf("ended!")
+		err := p.cmd.Run()
 		if err != nil {
 			p.cmdError <- fmt.Errorf("language plugin failed: %w", err)
 		} else {

internal/buildengine/languageplugin/go_plugin_test.go

@@ -32,7 +32,7 @@ func TestExtractModuleDepsGo(t *testing.T) {
 	uncheckedConfig, err := moduleconfig.LoadConfig(dir)
 	assert.NoError(t, err)
 
-	plugin, err := New(ctx, nil, uncheckedConfig.Language)
+	plugin, err := New(ctx, nil, uncheckedConfig.Language, "test")
 	assert.NoError(t, err)
 
 	customDefaults, err := plugin.ModuleConfigDefaults(ctx, uncheckedConfig.Dir)
@@ -85,7 +85,7 @@ func TestGoConfigDefaults(t *testing.T) {
 			dir, err := filepath.Abs(tt.dir)
 			assert.NoError(t, err)
 
-			plugin, err := New(ctx, nil, "go")
+			plugin, err := New(ctx, nil, "go", "test")
 			assert.NoError(t, err)
 
 			defaults, err := plugin.ModuleConfigDefaults(ctx, dir)

internal/buildengine/languageplugin/java_plugin_test.go

@@ -63,7 +63,7 @@ func TestJavaConfigDefaults(t *testing.T) {
 			dir, err := filepath.Abs(tt.dir)
 			assert.NoError(t, err)
 
-			plugin, err := New(ctx, nil, "java")
+			plugin, err := New(ctx, nil, "java", "test")
 			assert.NoError(t, err)
 
 			defaults, err := plugin.ModuleConfigDefaults(ctx, dir)

internal/buildengine/languageplugin/plugin.go

@@ -132,7 +132,7 @@ type LanguagePlugin interface {
 }
 
 // PluginFromConfig creates a new language plugin from the given config.
-func New(ctx context.Context, bindAllocator *bind.BindAllocator, language string) (p LanguagePlugin, err error) {
+func New(ctx context.Context, bindAllocator *bind.BindAllocator, language, name string) (p LanguagePlugin, err error) {
 	switch language {
 	case "go":
 		return newGoPlugin(ctx), nil
@@ -145,7 +145,7 @@ func New(ctx context.Context, bindAllocator *bind.BindAllocator, language string
 		if err != nil {
 			return nil, fmt.Errorf("failed to allocate port for external plugin: %w", err)
 		}
-		return newExternalPlugin(ctx, port, language)
+		return newExternalPlugin(ctx, port, language, name)
 	}
 }
 

python-runtime/cmd/ftl-language-python/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"os"
 
 	"github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1/language/languagepbconnect"
 	"github.com/TBD54566975/ftl/common/plugin"
@@ -11,7 +12,7 @@ import (
 func main() {
 	plugin.Start(
 		context.Background(),
-		"ftl-language-python",
+		os.Getenv("FTL_NAME"),
 		createService,
 		languagepbconnect.LanguageServiceName,
 		languagepbconnect.NewLanguageServiceHandler,