Don't run any agent service when running otel subcommand (#5748)

* Remove need to run agent while running otel subcommand.

* Cleanup.

* Fix tests.

* Fix tests.

* Few more cleanups.

* Mage check.

(cherry picked from commit 3f1e4da)

internal/pkg/agent/application/application.go

@@ -28,7 +28,6 @@ import (
 	"github.com/elastic/elastic-agent/internal/pkg/capabilities"
 	"github.com/elastic/elastic-agent/internal/pkg/composable"
 	"github.com/elastic/elastic-agent/internal/pkg/config"
-	"github.com/elastic/elastic-agent/internal/pkg/otel"
 	"github.com/elastic/elastic-agent/internal/pkg/release"
 	"github.com/elastic/elastic-agent/pkg/component"
 	"github.com/elastic/elastic-agent/pkg/component/runtime"
@@ -47,13 +46,11 @@ func New(
 	testingMode bool,
 	fleetInitTimeout time.Duration,
 	disableMonitoring bool,
-	runAsOtel bool,
 	modifiers ...component.PlatformModifier,
 ) (*coordinator.Coordinator, coordinator.ConfigManager, composable.Controller, error) {
 
 	err := version.InitVersionError()
-	if err != nil && !runAsOtel {
-		// ignore this error when running in otel mode
+	if err != nil {
 		// non-fatal error, log a warning and move on
 		log.With("error.message", err).Warnf("Error initializing version information: falling back to %s", release.Version())
 	}
@@ -92,13 +89,7 @@ func New(
 		log.Infof("Loading baseline config from %v", pathConfigFile)
 		rawConfig, err = config.LoadFile(pathConfigFile)
 		if err != nil {
-			if !runAsOtel {
-				return nil, nil, nil, fmt.Errorf("failed to load configuration: %w", err)
-			}
-
-			// initialize with empty config, configuration file is not necessary in otel mode,
-			// best effort is fine
-			rawConfig = config.New()
+			return nil, nil, nil, fmt.Errorf("failed to load configuration: %w", err)
 		}
 	}
 	if err := info.InjectAgentConfig(rawConfig); err != nil {
@@ -124,7 +115,6 @@ func New(
 		tracer,
 		monitor,
 		cfg.Settings.GRPC,
-		runAsOtel,
 	)
 	if err != nil {
 		return nil, nil, nil, fmt.Errorf("failed to initialize runtime manager: %w", err)
@@ -141,9 +131,6 @@ func New(
 
 		// testing mode uses a config manager that takes configuration from over the control protocol
 		configMgr = newTestingModeConfigManager(log)
-	} else if runAsOtel {
-		// ignoring configuration in elastic-agent.yml
-		configMgr = otel.NewOtelModeConfigManager()
 	} else if configuration.IsStandalone(cfg.Fleet) {
 		log.Info("Parsed configuration and determined agent is managed locally")
 
@@ -187,13 +174,10 @@ func New(
 		}
 	}
 
-	var varsManager composable.Controller
-	if !runAsOtel {
-		// no need for vars in otel mode
-		varsManager, err = composable.New(log, rawConfig, composableManaged)
-		if err != nil {
-			return nil, nil, nil, errors.New(err, "failed to initialize composable controller")
-		}
+	// no need for vars in otel mode
+	varsManager, err := composable.New(log, rawConfig, composableManaged)
+	if err != nil {
+		return nil, nil, nil, errors.New(err, "failed to initialize composable controller")
 	}
 
 	coord := coordinator.New(log, cfg, logLevel, agentInfo, specs, reexec, upgrader, runtime, configMgr, varsManager, caps, monitor, isManaged, compModifiers...)

internal/pkg/agent/application/application_test.go

@@ -63,7 +63,6 @@ func TestLimitsLog(t *testing.T) {
 		true,              // testingMode
 		time.Millisecond,  // fleetInitTimeout
 		true,              // disable monitoring
-		false,             // not otel mode
 	)
 	require.NoError(t, err)
 

internal/pkg/agent/application/coordinator/coordinator_test.go

@@ -895,7 +895,7 @@ func createCoordinator(t *testing.T, ctx context.Context, opts ...CoordinatorOpt
 	monitoringMgr := newTestMonitoringMgr()
 	cfg := configuration.DefaultGRPCConfig()
 	cfg.Port = 0
-	rm, err := runtime.NewManager(l, l, ai, apmtest.DiscardTracer, monitoringMgr, cfg, false)
+	rm, err := runtime.NewManager(l, l, ai, apmtest.DiscardTracer, monitoringMgr, cfg)
 	require.NoError(t, err)
 
 	caps, err := capabilities.LoadFile(paths.AgentCapabilitiesPath(), l)

internal/pkg/agent/cmd/otel.go

@@ -8,14 +8,11 @@ package cmd
 
 import (
 	"context"
-	goerrors "errors"
-	"sync"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 
 	"github.com/elastic/elastic-agent-libs/service"
-	"github.com/elastic/elastic-agent/internal/pkg/agent/errors"
 	"github.com/elastic/elastic-agent/internal/pkg/cli"
 	"github.com/elastic/elastic-agent/internal/pkg/otel"
 )
@@ -79,42 +76,5 @@ func runCollector(cmdCtx context.Context, configFiles []string) error {
 	defer cancel()
 	go service.ProcessWindowsControlEvents(stopCollector)
 
-	var otelStartWg sync.WaitGroup
-	var errs []error
-	var awaiters awaiters
-
-	otelAwaiter := make(chan struct{})
-	awaiters = append(awaiters, otelAwaiter)
-
-	otelStartWg.Add(1)
-	go func() {
-		otelStartWg.Done()
-		if err := otel.Run(ctx, stop, configFiles); err != nil {
-			errs = append(errs, err)
-			// otel collector finished with an error, exit run loop
-			cancel()
-		}
-
-		// close awaiter handled in run loop
-		close(otelAwaiter)
-	}()
-
-	// wait for otel to start
-	otelStartWg.Wait()
-
-	if err := runElasticAgent(
-		ctx,
-		cancel,
-		nil,      // no config overrides
-		stop,     // service hook
-		false,    // not in testing mode
-		0,        // no fleet config
-		true,     // is otel mode
-		awaiters, // wait for otel to finish
-	); err != nil && !errors.Is(err, context.Canceled) {
-		errs = append(errs, err)
-	}
-
-	return goerrors.Join(errs...)
-
+	return otel.Run(ctx, stop, configFiles)
 }

internal/pkg/agent/cmd/run.go

@@ -64,7 +64,6 @@ const (
 
 type (
 	cfgOverrider func(cfg *configuration.Configuration)
-	awaiters     []<-chan struct{}
 )
 
 func newRunCommandWithArgs(_ []string, streams *cli.IOStreams) *cobra.Command {
@@ -155,7 +154,7 @@ func run(override cfgOverrider, testingMode bool, fleetInitTimeout time.Duration
 	defer cancel()
 	go service.ProcessWindowsControlEvents(stopBeat)
 
-	return runElasticAgent(ctx, cancel, override, stop, testingMode, fleetInitTimeout, false, nil, modifiers...)
+	return runElasticAgent(ctx, cancel, override, stop, testingMode, fleetInitTimeout, modifiers...)
 }
 
 func logReturn(l *logger.Logger, err error) error {
@@ -165,8 +164,8 @@ func logReturn(l *logger.Logger, err error) error {
 	return err
 }
 
-func runElasticAgent(ctx context.Context, cancel context.CancelFunc, override cfgOverrider, stop chan bool, testingMode bool, fleetInitTimeout time.Duration, runAsOtel bool, awaiters awaiters, modifiers ...component.PlatformModifier) error {
-	cfg, err := loadConfig(ctx, override, runAsOtel)
+func runElasticAgent(ctx context.Context, cancel context.CancelFunc, override cfgOverrider, stop chan bool, testingMode bool, fleetInitTimeout time.Duration, modifiers ...component.PlatformModifier) error {
+	cfg, err := loadConfig(ctx, override)
 	if err != nil {
 		return err
 	}
@@ -205,7 +204,7 @@ func runElasticAgent(ctx context.Context, cancel context.CancelFunc, override cf
 	pathConfigFile := paths.AgentConfigFile()
 
 	// agent ID needs to stay empty in bootstrap mode
-	createAgentID := !runAsOtel
+	createAgentID := true
 	if cfg.Fleet != nil && cfg.Fleet.Server != nil && cfg.Fleet.Server.Bootstrap {
 		createAgentID = false
 	}
@@ -285,7 +284,7 @@ func runElasticAgent(ctx context.Context, cancel context.CancelFunc, override cf
 		l.Info("APM instrumentation disabled")
 	}
 
-	coord, configMgr, composable, err := application.New(ctx, l, baseLogger, logLvl, agentInfo, rex, tracer, testingMode, fleetInitTimeout, configuration.IsFleetServerBootstrap(cfg.Fleet), runAsOtel, modifiers...)
+	coord, configMgr, composable, err := application.New(ctx, l, baseLogger, logLvl, agentInfo, rex, tracer, testingMode, fleetInitTimeout, configuration.IsFleetServerBootstrap(cfg.Fleet), modifiers...)
 	if err != nil {
 		return logReturn(l, err)
 	}
@@ -397,9 +396,6 @@ LOOP:
 	}
 	cancel()
 	err = <-appErr
-	for _, a := range awaiters {
-		<-a // wait for awaiter to be done
-	}
 
 	if logShutdown {
 		l.Info("Shutting down completed.")
@@ -410,16 +406,7 @@ LOOP:
 	return logReturn(l, err)
 }
 
-func loadConfig(ctx context.Context, override cfgOverrider, runAsOtel bool) (*configuration.Configuration, error) {
-	if runAsOtel {
-		defaultCfg := configuration.DefaultConfiguration()
-		// disable monitoring to avoid injection of monitoring components
-		// in case inputs are not empty
-		defaultCfg.Settings.MonitoringConfig.Enabled = false
-		defaultCfg.Settings.V1MonitoringEnabled = false
-		return defaultCfg, nil
-	}
-
+func loadConfig(ctx context.Context, override cfgOverrider) (*configuration.Configuration, error) {
 	pathConfigFile := paths.ConfigFile()
 	rawConfig, err := config.LoadFile(pathConfigFile)
 	if err != nil {
@@ -592,7 +579,7 @@ func tryDelayEnroll(ctx context.Context, logger *logger.Logger, cfg *configurati
 			errors.M("path", enrollPath)))
 	}
 	logger.Info("Successfully performed delayed enrollment of this Elastic Agent.")
-	return loadConfig(ctx, override, false)
+	return loadConfig(ctx, override)
 }
 
 func initTracer(agentName, version string, mcfg *monitoringCfg.MonitoringConfig) (*apm.Tracer, error) {

pkg/component/runtime/manager.go

@@ -145,8 +145,7 @@ type Manager struct {
 
 	// doneChan is closed when Manager is shutting down to signal that any
 	// pending requests should be canceled.
-	doneChan  chan struct{}
-	runAsOtel bool
+	doneChan chan struct{}
 }
 
 // NewManager creates a new manager.
@@ -157,7 +156,6 @@ func NewManager(
 	tracer *apm.Tracer,
 	monitor MonitoringManager,
 	grpcConfig *configuration.GRPCConfig,
-	runAsOtel bool,
 ) (*Manager, error) {
 	ca, err := authority.NewCA()
 	if err != nil {
@@ -193,7 +191,6 @@ func NewManager(
 		grpcConfig:     grpcConfig,
 		serverReady:    make(chan struct{}),
 		doneChan:       make(chan struct{}),
-		runAsOtel:      runAsOtel,
 	}
 	return m, nil
 }
@@ -212,56 +209,54 @@ func (m *Manager) Run(ctx context.Context) error {
 		server   *grpc.Server
 		wgServer sync.WaitGroup
 	)
-	if !m.runAsOtel {
-		if m.isLocal {
-			listener, err = ipc.CreateListener(m.logger, m.listenAddr)
-		} else {
-			listener, err = net.Listen("tcp", m.listenAddr)
-		}
-
-		if err != nil {
-			return fmt.Errorf("error starting tcp listener for runtime manager: %w", err)
-		}
-
-		if m.isLocal {
-			defer ipc.CleanupListener(m.logger, m.listenAddr)
-		} else {
-			m.listenPort = listener.Addr().(*net.TCPAddr).Port
-		}
+	if m.isLocal {
+		listener, err = ipc.CreateListener(m.logger, m.listenAddr)
+	} else {
+		listener, err = net.Listen("tcp", m.listenAddr)
+	}
 
-		certPool := x509.NewCertPool()
-		if ok := certPool.AppendCertsFromPEM(m.ca.Crt()); !ok {
-			return errors.New("failed to append root CA")
-		}
-		creds := credentials.NewTLS(&tls.Config{
-			ClientAuth:     tls.RequireAndVerifyClientCert,
-			ClientCAs:      certPool,
-			GetCertificate: m.getCertificate,
-			MinVersion:     tls.VersionTLS12,
-		})
-		m.logger.Infof("Starting grpc control protocol listener on port %v with max_message_size %v", m.grpcConfig.Port, m.grpcConfig.MaxMsgSize)
-		if m.tracer != nil {
-			apmInterceptor := apmgrpc.NewUnaryServerInterceptor(apmgrpc.WithRecovery(), apmgrpc.WithTracer(m.tracer))
-			server = grpc.NewServer(
-				grpc.UnaryInterceptor(apmInterceptor),
-				grpc.Creds(creds),
-				grpc.MaxRecvMsgSize(m.grpcConfig.MaxMsgSize),
-			)
-		} else {
-			server = grpc.NewServer(
-				grpc.Creds(creds),
-				grpc.MaxRecvMsgSize(m.grpcConfig.MaxMsgSize),
-			)
-		}
-		proto.RegisterElasticAgentServer(server, m)
+	if err != nil {
+		return fmt.Errorf("error starting tcp listener for runtime manager: %w", err)
+	}
 
-		// start serving GRPC connections
-		wgServer.Add(1)
-		go func() {
-			defer wgServer.Done()
-			m.serverLoop(ctx, listener, server)
-		}()
+	if m.isLocal {
+		defer ipc.CleanupListener(m.logger, m.listenAddr)
+	} else {
+		m.listenPort = listener.Addr().(*net.TCPAddr).Port
+	}
+
+	certPool := x509.NewCertPool()
+	if ok := certPool.AppendCertsFromPEM(m.ca.Crt()); !ok {
+		return errors.New("failed to append root CA")
+	}
+	creds := credentials.NewTLS(&tls.Config{
+		ClientAuth:     tls.RequireAndVerifyClientCert,
+		ClientCAs:      certPool,
+		GetCertificate: m.getCertificate,
+		MinVersion:     tls.VersionTLS12,
+	})
+	m.logger.Infof("Starting grpc control protocol listener on port %v with max_message_size %v", m.grpcConfig.Port, m.grpcConfig.MaxMsgSize)
+	if m.tracer != nil {
+		apmInterceptor := apmgrpc.NewUnaryServerInterceptor(apmgrpc.WithRecovery(), apmgrpc.WithTracer(m.tracer))
+		server = grpc.NewServer(
+			grpc.UnaryInterceptor(apmInterceptor),
+			grpc.Creds(creds),
+			grpc.MaxRecvMsgSize(m.grpcConfig.MaxMsgSize),
+		)
+	} else {
+		server = grpc.NewServer(
+			grpc.Creds(creds),
+			grpc.MaxRecvMsgSize(m.grpcConfig.MaxMsgSize),
+		)
 	}
+	proto.RegisterElasticAgentServer(server, m)
+
+	// start serving GRPC connections
+	wgServer.Add(1)
+	go func() {
+		defer wgServer.Done()
+		m.serverLoop(ctx, listener, server)
+	}()
 
 	// Start the run loop, which continues on the main goroutine
 	// until the context is canceled.
@@ -271,13 +266,11 @@ func (m *Manager) Run(ctx context.Context) error {
 	m.shutdown()
 
 	// Close the rpc listener and wait for serverLoop to return
-	if !m.runAsOtel {
-		listener.Close()
-		wgServer.Wait()
+	listener.Close()
+	wgServer.Wait()
 
-		// Cancel any remaining connections
-		server.Stop()
-	}
+	// Cancel any remaining connections
+	server.Stop()
 	return ctx.Err()
 }