feat: rework otel config package to avoid globals

Author: pkoutsovasilis

internal/pkg/agent/application/application.go

@@ -123,17 +123,16 @@ func New(
 		override(cfg)
 	}
 
-	otelconfig.SetExecutionModeFromConfig(log, rawConfig)
-	otelExecMode := otelconfig.GetExecutionMode()
-	isOtelSubprocessExecution := otelExecMode == otelmanager.SubprocessExecutionMode
+	otelExecMode := otelconfig.GetExecutionModeFromConfig(log, rawConfig)
+	isOtelExecModeSubprocess := otelExecMode == otelmanager.SubprocessExecutionMode
 
 	// monitoring is not supported in bootstrap mode https://github.com/elastic/elastic-agent/issues/1761
 	isMonitoringSupported := !disableMonitoring && cfg.Settings.V1MonitoringEnabled
 	upgrader, err := upgrade.NewUpgrader(log, cfg.Settings.DownloadConfig, cfg.Settings.Upgrade, agentInfo, new(upgrade.AgentWatcherHelper))
 	if err != nil {
 		return nil, nil, nil, fmt.Errorf("failed to create upgrader: %w", err)
 	}
-	monitor := monitoring.New(isMonitoringSupported, cfg.Settings.DownloadConfig.OS(), cfg.Settings.MonitoringConfig, agentInfo, isOtelSubprocessExecution)
+	monitor := monitoring.New(isMonitoringSupported, cfg.Settings.DownloadConfig.OS(), cfg.Settings.MonitoringConfig, agentInfo, isOtelExecModeSubprocess)
 
 	runtime, err := runtime.NewManager(
 		log,

internal/pkg/agent/cmd/inspect.go

@@ -30,6 +30,7 @@ import (
 	"github.com/elastic/elastic-agent/internal/pkg/config/operations"
 	"github.com/elastic/elastic-agent/internal/pkg/diagnostics"
 	otelconfig "github.com/elastic/elastic-agent/internal/pkg/otel/config"
+	"github.com/elastic/elastic-agent/internal/pkg/otel/manager"
 	"github.com/elastic/elastic-agent/pkg/component"
 	"github.com/elastic/elastic-agent/pkg/core/logger"
 	"github.com/elastic/elastic-agent/pkg/utils"
@@ -409,8 +410,9 @@ func getMonitoringFn(ctx context.Context, logger *logger.Logger, cfg map[string]
 	if err != nil {
 		return nil, fmt.Errorf("could not load agent info: %w", err)
 	}
-	otelconfig.SetExecutionModeFromConfig(logger, config)
-	monitor := monitoring.New(agentCfg.Settings.V1MonitoringEnabled, agentCfg.Settings.DownloadConfig.OS(), agentCfg.Settings.MonitoringConfig, agentInfo, otelconfig.IsSubprocessExecution())
+	otelExecMode := otelconfig.GetExecutionModeFromConfig(logger, config)
+	isOtelExecModeSubprocess := otelExecMode == manager.SubprocessExecutionMode
+	monitor := monitoring.New(agentCfg.Settings.V1MonitoringEnabled, agentCfg.Settings.DownloadConfig.OS(), agentCfg.Settings.MonitoringConfig, agentInfo, isOtelExecModeSubprocess)
 	return monitor.MonitoringConfig, nil
 }
 

internal/pkg/otel/config/config.go

@@ -10,39 +10,37 @@ import (
 	"github.com/elastic/elastic-agent/internal/pkg/otel/manager"
 )
 
-var executionMode = manager.EmbeddedExecutionMode
+const defaultExecMode = manager.EmbeddedExecutionMode
 
 type execModeConfig struct {
 	Agent struct {
 		Features struct {
 			Otel *struct {
-				SubprocessExecution bool `json:"subprocess_execution" yaml:"subprocess_execution" config:"subprocess_execution"`
+				SubprocessExecution *bool `json:"subprocess_execution,omitempty" yaml:"subprocess_execution,omitempty" config:"subprocess_execution,omitempty"`
 			} `json:"otel,omitempty" yaml:"otel,omitempty" config:"otel,omitempty"`
 		} `json:"features" yaml:"features" config:"features"`
 	} `json:"agent" yaml:"agent" config:"agent"`
 }
 
-// SetExecutionModeFromConfig sets the execution mode of the OTel runtime based on the config.
-func SetExecutionModeFromConfig(log *logp.Logger, conf *config.Config) {
+// GetExecutionModeFromConfig returns the execution mode of the OTel runtime based on the config.
+func GetExecutionModeFromConfig(log *logp.Logger, conf *config.Config) manager.ExecutionMode {
 	var c execModeConfig
 	if err := conf.UnpackTo(&c); err != nil {
-		log.Warnf("failed to unpack config in otel init execution mode: %v", err)
-		return
+		log.Warnf("failed to unpack config when getting otel runtime execution mode: %v", err)
+		return defaultExecMode
 	}
 
-	if c.Agent.Features.Otel != nil && c.Agent.Features.Otel.SubprocessExecution {
-		executionMode = manager.SubprocessExecutionMode
-	} else {
-		executionMode = manager.EmbeddedExecutionMode
+	if c.Agent.Features.Otel == nil {
+		return defaultExecMode
 	}
-}
 
-// GetExecutionMode returns the execution mode of the OTel runtime.
-func GetExecutionMode() manager.ExecutionMode {
-	return executionMode
-}
+	if c.Agent.Features.Otel.SubprocessExecution == nil {
+		return defaultExecMode
+	}
 
-// IsSubprocessExecution returns true if the OTel runtime is running in subprocess mode.
-func IsSubprocessExecution() bool {
-	return executionMode == manager.SubprocessExecutionMode
+	if *c.Agent.Features.Otel.SubprocessExecution {
+		return manager.SubprocessExecutionMode
+	} else {
+		return manager.EmbeddedExecutionMode
+	}
 }