|
| 1 | +""" |
| 2 | +This example covers the following: |
| 3 | + - Create headless server |
| 4 | + - Create statefulset |
| 5 | + - Update statefulset |
| 6 | + - List contoller revisions which belong to specified statefulset |
| 7 | + - Roll out statefulset |
| 8 | +Note: |
| 9 | + If your kubernetes version is lower than 1.22(exclude 1.22), the kubernetes-client version must be lower than 1.22(alse exclude 1.22). |
| 10 | + Because new feature 'AvailableReplicas' for StatefulSetStatus is supported in native kubernetes since version 1.22, mismatch version between kubernetes and kubernetes-client will raise execption ValueError |
| 11 | +""" |
| 12 | + |
| 13 | + |
| 14 | +from kubernetes import client, config |
| 15 | + |
| 16 | + |
| 17 | +def create_service(core_v1_api): |
| 18 | + body = client.V1Service( |
| 19 | + api_version="v1", |
| 20 | + kind="Service", |
| 21 | + metadata=client.V1ObjectMeta( |
| 22 | + name="redis-test-svc" |
| 23 | + ), |
| 24 | + spec=client.V1ServiceSpec( |
| 25 | + selector={"app": "redis"}, |
| 26 | + cluster_ip="None", |
| 27 | + type="ClusterIP", |
| 28 | + ports=[client.V1ServicePort( |
| 29 | + port=6379, |
| 30 | + target_port=6379 |
| 31 | + )] |
| 32 | + ) |
| 33 | + ) |
| 34 | + # Create the service in specified namespace |
| 35 | + # (Can replace "default" with a namespace you may have created) |
| 36 | + core_v1_api.create_namespaced_service(namespace="default", body=body) |
| 37 | + |
| 38 | + |
| 39 | +def create_stateful_set_object(): |
| 40 | + container = client.V1Container( |
| 41 | + name="sts-redis", |
| 42 | + image="redis", |
| 43 | + image_pull_policy="IfNotPresent", |
| 44 | + ports=[client.V1ContainerPort(container_port=6379)], |
| 45 | + ) |
| 46 | + # Template |
| 47 | + template = client.V1PodTemplateSpec( |
| 48 | + metadata=client.V1ObjectMeta(labels={"app": "redis"}), |
| 49 | + spec=client.V1PodSpec(containers=[container])) |
| 50 | + # Spec |
| 51 | + spec = client.V1StatefulSetSpec( |
| 52 | + replicas=1, |
| 53 | + service_name="redis-test-svc", |
| 54 | + selector=client.V1LabelSelector( |
| 55 | + match_labels={"app": "redis"} |
| 56 | + ), |
| 57 | + template=template) |
| 58 | + # StatefulSet |
| 59 | + statefulset = client.V1StatefulSet( |
| 60 | + api_version="apps/v1", |
| 61 | + kind="StatefulSet", |
| 62 | + metadata=client.V1ObjectMeta(name="statefulset-redis"), |
| 63 | + spec=spec) |
| 64 | + |
| 65 | + return statefulset |
| 66 | + |
| 67 | + |
| 68 | +def create_stateful_set(apps_v1_api, stateful_set_object): |
| 69 | + # Create the Statefulset in default namespace |
| 70 | + # You can replace the namespace with you have created |
| 71 | + apps_v1_api.create_namespaced_stateful_set( |
| 72 | + namespace="default", body=stateful_set_object |
| 73 | + ) |
| 74 | + |
| 75 | + |
| 76 | +def update_stateful_set(apps_v1_api, statefulset): |
| 77 | + # Update container image |
| 78 | + statefulset.spec.template.spec.containers[0].image = "redis:6.2" |
| 79 | + statefulset_name = statefulset.metadata.name |
| 80 | + # Patch the statefulset |
| 81 | + apps_v1_api.patch_namespaced_stateful_set( |
| 82 | + name=statefulset_name, namespace="default", body=statefulset |
| 83 | + ) |
| 84 | + |
| 85 | + |
| 86 | +def list_controller_revision(apps_v1_api, namespace, stateful_set_name): |
| 87 | + # Get all controller revisions in specified namespace |
| 88 | + controller_revision_list = apps_v1_api.list_namespaced_controller_revision( |
| 89 | + namespace) |
| 90 | + # Get all controller revisions which belong to specified statefulset. |
| 91 | + controller_revision_belong_to_sts = [] |
| 92 | + for controller_revision in controller_revision_list.items: |
| 93 | + owner_kind = controller_revision.metadata.owner_references[0].kind |
| 94 | + owner_name = controller_revision.metadata.owner_references[0].name |
| 95 | + if owner_kind == "StatefulSet" and owner_name == stateful_set_name: |
| 96 | + controller_revision_belong_to_sts.append( |
| 97 | + (controller_revision.metadata.name, controller_revision.revision)) |
| 98 | + return sorted(controller_revision_belong_to_sts, key=lambda x: x[1]) |
| 99 | + |
| 100 | + |
| 101 | +def rollout_namespaced_stateful_set( |
| 102 | + apps_v1_api, |
| 103 | + name, |
| 104 | + namespace, |
| 105 | + controller_revision_name): |
| 106 | + |
| 107 | + # Get the specified controller revision object |
| 108 | + _controller_revision = apps_v1_api.read_namespaced_controller_revision( |
| 109 | + controller_revision_name, namespace) |
| 110 | + # Roll out statefulset to the specified revision |
| 111 | + apps_v1_api.patch_namespaced_stateful_set( |
| 112 | + name, namespace, body=_controller_revision.data) |
| 113 | + |
| 114 | + |
| 115 | +def main(): |
| 116 | + # Loading the local kubeconfig |
| 117 | + config.load_kube_config() |
| 118 | + apps_v1_api = client.AppsV1Api() |
| 119 | + core_v1_api = client.CoreV1Api() |
| 120 | + stateful_set_obj = create_stateful_set_object() |
| 121 | + |
| 122 | + create_service(core_v1_api) |
| 123 | + |
| 124 | + create_stateful_set(apps_v1_api, stateful_set_obj) |
| 125 | + |
| 126 | + update_stateful_set(apps_v1_api, stateful_set_obj) |
| 127 | + |
| 128 | + # Wait for finishing creation of controller revision |
| 129 | + import time |
| 130 | + time.sleep(15) |
| 131 | + # List the controller revison |
| 132 | + controller_revisions = list_controller_revision( |
| 133 | + apps_v1_api, "default", "statefulset-redis") |
| 134 | + rollout_namespaced_stateful_set( |
| 135 | + apps_v1_api, |
| 136 | + "statefulset-redis", |
| 137 | + "default", |
| 138 | + controller_revisions[0][0]) |
| 139 | + |
| 140 | + |
| 141 | +if __name__ == "__main__": |
| 142 | + main() |
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