diff --git a/pkg/extension/templates/extension.yaml b/pkg/extension/templates/extension.yaml
index ad69a5c..b1daf72 100644
--- a/pkg/extension/templates/extension.yaml
+++ b/pkg/extension/templates/extension.yaml
@@ -54,3 +54,10 @@ installationMode: HostOnly
 #    type: extension
 #    version: ">= 2.2.0"
 #    required: true
+# Add init containers to the extension installation job to execute custom tasks (eg: CRDs upgrade).
+# Support unified or separate configuration of init container image for each stage.
+#annotations:
+#  executor-hook-image.kubesphere.io: ...
+#  executor-hook-image.kubesphere.io/install: ...
+#  executor-hook-image.kubesphere.io/upgrade: ...
+#  executor-hook-image.kubesphere.io/uninstall: ...
diff --git a/pkg/extension/type.go b/pkg/extension/type.go
index f33aaff..7d07d07 100644
--- a/pkg/extension/type.go
+++ b/pkg/extension/type.go
@@ -58,6 +58,7 @@ type Metadata struct {
 	Namespace            string                                               `json:"namespace,omitempty"`
 	Images               []string                                             `json:"images,omitempty"`
 	ExternalDependencies []corev1alpha1.ExternalDependency                    `json:"externalDependencies,omitempty"`
+	Annotations          map[string]string                                    `json:"annotations,omitempty"`
 }
 
 func ParseMetadata(data []byte) (*Metadata, error) {
@@ -119,6 +120,7 @@ func (md *Metadata) ToChartYaml() (*chart.Metadata, error) {
 		Description:  string(md.Description[corev1alpha1.DefaultLanguageCode]),
 		Icon:         md.Icon,
 		Maintainers:  md.Maintainers,
+		Annotations:  md.Annotations,
 	}
 	return &c, nil
 }
@@ -213,6 +215,7 @@ func (ext *Extension) ToKubernetesResources() []runtimeclient.Object {
 				corev1alpha1.ExtensionReferenceLabel: ext.Metadata.Name,
 				corev1alpha1.CategoryLabel:           ext.Metadata.Category,
 			},
+			Annotations: ext.Metadata.Annotations,
 		},
 		Spec: corev1alpha1.ExtensionVersionSpec{
 			InstallationMode: ext.Metadata.InstallationMode,