added log message

Author: michalpristas

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

@@ -1637,7 +1637,7 @@ func (c *Coordinator) processConfigAgent(ctx context.Context, cfg *config.Config
 	// override retrieved config from Fleet with persisted config from AgentConfig file
 
 	if c.caps != nil {
-		if err := applyPersistedConfig(cfg, paths.ConfigFile(), c.isContainerizedEnvironment, c.caps.AllowFleetOverride); err != nil {
+		if err := applyPersistedConfig(c.logger, cfg, paths.ConfigFile(), c.isContainerizedEnvironment, c.caps.AllowFleetOverride); err != nil {
 			return fmt.Errorf("could not apply persisted configuration: %w", err)
 		}
 	}
@@ -1729,10 +1729,11 @@ func (c *Coordinator) generateAST(cfg *config.Config, m map[string]interface{})
 	return nil
 }
 
-func applyPersistedConfig(cfg *config.Config, configFile string, checkFns ...func() bool) error {
-	for _, checkFn := range checkFns {
+func applyPersistedConfig(logger *logger.Logger, cfg *config.Config, configFile string, checkFns ...func() bool) error {
+	for checkNo, checkFn := range checkFns {
 		if !checkFn() {
 			// Feature is disabled, nothing to do
+			logger.Infof("Applying persisted configuration is disabled by check with idx %d.", checkNo)
 			return nil
 		}
 	}

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

@@ -50,6 +50,7 @@ import (
 	agentclient "github.com/elastic/elastic-agent/pkg/control/v2/client"
 	"github.com/elastic/elastic-agent/pkg/control/v2/cproto"
 	"github.com/elastic/elastic-agent/pkg/core/logger"
+	"github.com/elastic/elastic-agent/pkg/core/logger/loggertest"
 )
 
 const (
@@ -1029,9 +1030,22 @@ func Test_ApplyPersistedConfig(t *testing.T) {
 			cfg, err := config.LoadFile(filepath.Join(".", "testdata", "config.yaml"))
 			require.NoError(t, err)
 
-			err = applyPersistedConfig(cfg, cfgFile, func() bool { return tc.featureEnable })
+			testLogger, observedLogs := loggertest.New("")
+			err = applyPersistedConfig(testLogger, cfg, cfgFile, func() bool { return tc.featureEnable })
 			require.NoError(t, err)
 
+			found := false
+			// check that a log message was emitted about disabling kafka output
+			logs := observedLogs.All()
+			for _, logEntry := range logs {
+				if strings.Contains(logEntry.Message, "is disabled") {
+					found = true
+					break
+				}
+			}
+
+			require.NotEqualf(t, tc.featureEnable, found, "expected log message")
+
 			c := &configuration.Configuration{}
 			require.NoError(t, cfg.Agent.Unpack(&c))