init with empty available components if host components is nil and ReportsAvailableComponents is set to true

Signed-off-by: Florian Bacher <[email protected]>

Author: bacherfl

extension/opampextension/config_test.go

@@ -40,8 +40,9 @@ func TestUnmarshalConfig(t *testing.T) {
 			},
 			InstanceUID: "01BX5ZZKBKACTAV9WEVGEMMVRZ",
 			Capabilities: Capabilities{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
 			PPIDPollInterval: 5 * time.Second,
 		}, cfg)
@@ -65,8 +66,9 @@ func TestUnmarshalHttpConfig(t *testing.T) {
 			},
 			InstanceUID: "01BX5ZZKBKACTAV9WEVGEMMVRZ",
 			Capabilities: Capabilities{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
 			PPIDPollInterval: 5 * time.Second,
 		}, cfg)

extension/opampextension/opamp_agent.go

@@ -168,6 +168,9 @@ func (o *opampAgent) Start(ctx context.Context, host component.Host) error {
 
 	if mi, ok := host.(moduleInfo); ok {
 		o.initAvailableComponents(mi.GetModuleInfos())
+	} else if o.capabilities.ReportsAvailableComponents {
+		// init empty availableComponents to not get an error when starting the opampClient
+		o.initAvailableComponents(service.ModuleInfos{})
 	}
 
 	if o.availableComponents != nil {