add example to demonstrate a rolling restart of the deployment

Priyankasaggu11929 · Priyankasaggu11929 · commit 83f92cc0b50f · 2021-05-03T14:44:25.000+05:30
diff --git a/examples/dynamic-client/deployment_rolling_restart.py b/examples/dynamic-client/deployment_rolling_restart.py
@@ -0,0 +1,120 @@
+# Copyright 2021 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+This example demonstrates the following:
+    - Creation of a k8s deployment using dynamic-client
+    - Rolling restart of the deployment (demonstrate patch/update action)
+    - Listing & deletion of the deployment
+"""
+
+
+from kubernetes import config, dynamic
+from kubernetes.client import api_client
+import datetime
+import pytz
+
+def main():
+    # Creating a dynamic client
+    client = dynamic.DynamicClient(
+        api_client.ApiClient(configuration=config.load_kube_config())
+    )
+
+    # fetching the deployment api
+    api = client.resources.get(api_version="apps/v1", kind="Deployment")
+
+    name = "nginx-deployment"
+
+    deployment_manifest = {
+        "apiVersion": "apps/v1",
+        "kind": "Deployment",
+        "metadata": {"labels": {"app": "nginx"}, "name": name},
+        "spec": {
+            "replicas": 3,
+            "selector": {"matchLabels": {"app": "nginx"}},
+            "template": {
+                "metadata": {"labels": {"app": "nginx"}},
+                "spec": {
+                    "containers": [
+                        {
+                            "name": "nginx",
+                            "image": "nginx:1.14.2",
+                            "ports": [{"containerPort": 80}],
+                        }
+                    ]
+                },
+            },
+        },
+    }
+
+    # Creating deployment `nginx-deployment` in the `default` namespace
+
+    deployment = api.create(body=deployment_manifest, namespace="default")
+
+    print("\n[INFO] deployment `nginx-deployment` created\n")
+
+    # Listing deployment `nginx-deployment` in the `default` namespace
+
+    deployment_created = api.get(name=name, namespace="default")
+
+    print("%s\t%s\t\t\t%s\t%s" % ("NAMESPACE", "NAME", "REVISION", "RESTARTED-AT"))
+    print(
+        "%s\t\t%s\t%s\t\t%s\n"
+        % (
+            deployment_created.metadata.namespace,
+            deployment_created.metadata.name,
+            deployment_created.metadata.annotations,
+            deployment_created.spec.template.metadata.annotations,
+        )
+    )
+
+    # Patching the `spec.template.metadata` section to add `kubectl.kubernetes.io/restartedAt` annotation
+    # In order to perform a rolling restart on the deployment `nginx-deployment`
+
+    deployment_manifest["spec"]["template"]["metadata"] = {
+        "annotations": {
+            "kubectl.kubernetes.io/restartedAt": datetime.datetime.utcnow()
+            .replace(tzinfo=pytz.UTC)
+            .isoformat()
+        }
+    }
+
+    deployment_patched = api.patch(
+        body=deployment_manifest, name=name, namespace="default"
+    )
+
+    print("\n[INFO] deployment `nginx-deployment` restarted\n")
+    print(
+        "%s\t%s\t\t\t%s\t\t\t\t\t\t%s"
+        % ("NAMESPACE", "NAME", "REVISION", "RESTARTED-AT")
+    )
+    print(
+        "%s\t\t%s\t%s\t\t%s\n"
+        % (
+            deployment_patched.metadata.namespace,
+            deployment_patched.metadata.name,
+            deployment_patched.metadata.annotations,
+            deployment_patched.spec.template.metadata.annotations,
+        )
+    )
+
+    # Deleting deployment `nginx-deployment` from the `default` namespace
+
+    deployment_deleted = api.delete(name=name, body={}, namespace="default")
+
+    print("\n[INFO] deployment `nginx-deployment` deleted\n")
+
+
+if __name__ == "__main__":
+    main()
