Add container lifecycle hooks in CDAPServiceSpec

api/v1alpha1/cdapmaster_types.go

@@ -136,6 +136,9 @@ type CDAPServiceSpec struct {
 	AdditionalVolumeMounts []corev1.VolumeMount `json:"additionalVolumeMounts,omitempty"`
 	// SecurityContext overrides the security context for the service pods.
 	SecurityContext *SecurityContext `json:"securityContext,omitempty"`
+	// Lifecycle is to specify Container Lifecycle hooks provided by Kubernetes for containers.
+	// This will not be applied to the init containers as init containers do not support lifecycle.
+	Lifecycle *corev1.Lifecycle `json:"lifecycle,omitempty"`
 }
 
 // CDAPScalableServiceSpec defines the base specification for master services that can have more than one instance.

controllers/deployment.go

@@ -184,7 +184,7 @@ func buildStatefulSets(master *v1alpha1.CDAPMaster, name string, services Servic
 			continue
 		}
 		env := addJavaMaxHeapEnvIfNotPresent(ss.Env, ss.Resources)
-		c := newContainerSpec(master, s, dataDir).setResources(ss.Resources).setEnv(env)
+		c := newContainerSpec(master, s, dataDir).setResources(ss.Resources).setEnv(env).setLifecycle(ss.Lifecycle)
 		if s == serviceUserInterface {
 			c = updateSpecForUserInterface(master, c)
 		}
@@ -274,7 +274,7 @@ func buildDeployment(master *v1alpha1.CDAPMaster, name string, services ServiceG
 			continue
 		}
 		env := addJavaMaxHeapEnvIfNotPresent(ss.Env, ss.Resources)
-		c := newContainerSpec(master, s, dataDir).setResources(ss.Resources).setEnv(env)
+		c := newContainerSpec(master, s, dataDir).setResources(ss.Resources).setEnv(env).setLifecycle(ss.Lifecycle)
 		if s == serviceUserInterface {
 			c = updateSpecForUserInterface(master, c)
 		}
@@ -339,7 +339,7 @@ func buildStatefulSetsObject(spec *StatefulSpec) (*reconciler.Object, error) {
 	if err != nil {
 		return nil, err
 	}
-	// For custom volumes and custom volume mounts, we directly pass structs from the spec to bypass the YAML templating logic.
+	// For container lifecycle hook, custom volumes, and custom volume mounts, we directly pass structs from the spec to bypass the YAML templating logic.
 	k8sObj, ok := obj.Obj.(*k8s.Object)
 	if !ok {
 		return nil, fmt.Errorf("failed to convert object to k8s object")
@@ -360,6 +360,7 @@ func buildStatefulSetsObject(spec *StatefulSpec) (*reconciler.Object, error) {
 		if err := addVolumeMountToContainer(&statefulSetObj.Spec.Template.Spec.Containers[index], spec.Base.AdditionalVolumeMounts); err != nil {
 			return nil, err
 		}
+		setLifecycleHookForContainer(&statefulSetObj.Spec.Template.Spec.Containers[index], spec.Containers[index].Lifecycle)
 	}
 	return obj, nil
 }
@@ -370,7 +371,7 @@ func buildDeploymentObject(spec *DeploymentSpec) (*reconciler.Object, error) {
 	if err != nil {
 		return nil, err
 	}
-	// For custom volumes and volume mounts, we directly pass structs from the spec to bypass the YAML templating logic.
+	// For container lifecycle hook, custom volumes, and volume mounts, we directly pass structs from the spec to bypass the YAML templating logic.
 	k8sObj, ok := obj.Obj.(*k8s.Object)
 	if !ok {
 		return nil, fmt.Errorf("failed to convert object to k8s object")
@@ -391,6 +392,7 @@ func buildDeploymentObject(spec *DeploymentSpec) (*reconciler.Object, error) {
 		if err := addVolumeMountToContainer(&deploymentObj.Spec.Template.Spec.Containers[index], spec.Base.AdditionalVolumeMounts); err != nil {
 			return nil, err
 		}
+		setLifecycleHookForContainer(&deploymentObj.Spec.Template.Spec.Containers[index], spec.Containers[index].Lifecycle)
 	}
 	return obj, nil
 }
@@ -419,6 +421,10 @@ func addVolumeMountToContainer(container *corev1.Container, volumeMountsToAdd []
 	return nil
 }
 
+func setLifecycleHookForContainer(container *corev1.Container, lifecycle *corev1.Lifecycle) {
+	container.Lifecycle = lifecycle
+}
+
 // Return a NodePort service to expose the supplied target service
 func buildNetworkService(master *v1alpha1.CDAPMaster, name NetworkServiceName, target ServiceName, labels map[string]string) (*NetworkServiceSpec, error) {
 	s, err := getCDAPExternalServiceSpec(master, target)

controllers/spec.go

@@ -45,6 +45,7 @@ type ContainerSpec struct {
 	ResourceRequests map[string]*resource.Quantity `json:"resourceRequests,omitempty"`
 	ResourceLimits   map[string]*resource.Quantity `json:"resourceLimits,omitempty"`
 	DataDir          string                        `json:"dataDir,omitempty"`
+	Lifecycle        *corev1.Lifecycle             `json:"lifecycle,omitempty"`
 }
 
 func newContainerSpec(master *v1alpha1.CDAPMaster, name, dataDir string) *ContainerSpec {
@@ -120,6 +121,11 @@ func (s *ContainerSpec) setResources(resources *corev1.ResourceRequirements) *Co
 	return s
 }
 
+func (s *ContainerSpec) setLifecycle(lifecycle *corev1.Lifecycle) *ContainerSpec {
+	s.Lifecycle = lifecycle
+	return s
+}
+
 // BaseSpec contains command fields for both StatefulSet and Deployment
 type BaseSpec struct {
 	Name                   string                    `json:"name,omitempty"`

controllers/testdata/appfabric.json

@@ -92,6 +92,13 @@
               "privileged": false,
               "readOnlyRootFilesystem": false
             },
+            "lifecycle": {
+              "preStop": {
+                "exec": {
+                  "command": ["sh", "-c", "echo hello"]
+                }
+              }
+            },
             "terminationMessagePath": "/dev/termination-log",
             "terminationMessagePolicy": "File",
             "volumeMounts": [

controllers/testdata/cdap_master_cr.json

@@ -56,7 +56,14 @@
           "name": "test-persistent-storage",
           "mountPath": "/mnt/teststorage"
         }
-      ]
+      ],
+      "lifecycle": {
+        "preStop": {
+          "exec": {
+            "command": ["sh", "-c", "echo hello"]
+          }
+        }
+      }
     },
     "authentication": {
       "metadata": {

templates/cdap-deployment.yaml

@@ -11,6 +11,12 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations under
 # the License.
+#
+#
+# NOTE: Some properties are highly nested and it is not feasible to pick them from the template file
+# hence those are added directly in the code.
+# For example, please check the method "../controllers/deployment.go#buildDeploymentObject" and see
+# how container's lifecycle property is added to the k8s object.
 apiVersion: apps/v1
 kind: Deployment
 metadata:

templates/cdap-sts.yaml

@@ -11,6 +11,12 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations under
 # the License.
+#
+#
+# NOTE: Some properties are highly nested and it is not feasible to pick them from the template file
+# hence those are added directly in the code.
+# For example, please check the method "../controllers/deployment.go#buildStatefulSetsObject" and see
+# how container's lifecycle property is added to the k8s object.
 apiVersion: apps/v1
 kind: StatefulSet
 metadata: