diff options
Diffstat (limited to 'ready.py')
| -rwxr-xr-x | ready.py | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/ready.py b/ready.py new file mode 100755 index 0000000..0640ed5 --- /dev/null +++ b/ready.py @@ -0,0 +1,309 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- +# Copyright © 2020 Orange +# +# 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. + +""" +Kubernetes readiness check. + +Checks if a container is ready or if a job is finished. +The check is done according to the name of the container, not the name of +its parent (Job, Deployment, StatefulSet, DaemonSet). +""" + +import getopt +import logging +import os +import sys +import time +import random + +from kubernetes import client +from kubernetes.client.rest import ApiException + +# extract env variables. +namespace = os.environ['NAMESPACE'] +cert = os.environ['CERT'] +host = os.environ['KUBERNETES_SERVICE_HOST'] +token_path = os.environ['TOKEN'] + +with open(token_path, 'r') as token_file: + token = token_file.read().replace('\n', '') + +# setup logging +log = logging.getLogger(__name__) +handler = logging.StreamHandler(sys.stdout) +formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s') +handler.setFormatter(formatter) +handler.setLevel(logging.INFO) +log.addHandler(handler) +log.setLevel(logging.INFO) + +configuration = client.Configuration() +configuration.host = "https://" + host +configuration.ssl_ca_cert = cert +configuration.api_key['authorization'] = token +configuration.api_key_prefix['authorization'] = 'Bearer' +coreV1Api = client.CoreV1Api(client.ApiClient(configuration)) +api_instance = client.ExtensionsV1beta1Api(client.ApiClient(configuration)) +api = client.AppsV1beta1Api(client.ApiClient(configuration)) +batchV1Api = client.BatchV1Api(client.ApiClient(configuration)) + + +def is_job_complete(job_name): + """ + Check if Job is complete. + + Args: + job_name (str): the name of the Job. + + Returns: + True if job is complete, false otherwise + """ + complete = False + log.info("Checking if %s is complete", job_name) + try: + response = batchV1Api.read_namespaced_job_status(job_name, namespace) + if response.status.succeeded == 1: + job_status_type = response.status.conditions[0].type + if job_status_type == "Complete": + complete = True + log.info("%s is complete", job_name) + else: + log.info("%s is NOT complete", job_name) + else: + log.info("%s has not succeeded yet", job_name) + except ApiException as exc: + log.error("Exception when calling read_namespaced_job_status: %s\n", + exc) + return complete + + +def wait_for_statefulset_complete(statefulset_name): + """ + Check if StatefulSet is running. + + Args: + statefulset_name (str): the name of the StatefulSet. + + Returns: + True if StatefulSet is running, false otherwise + """ + complete = False + try: + response = api.read_namespaced_stateful_set(statefulset_name, + namespace) + status = response.status + if (status.replicas == response.spec.replicas and + status.ready_replicas == response.spec.replicas and + status.observed_generation == response.metadata.generation): + log.info("Statefulset %s is ready", statefulset_name) + complete = True + else: + log.info("Statefulset %s is NOT ready", statefulset_name) + except ApiException as exc: + log.error("Exception when waiting for Statefulset status: %s\n", exc) + return complete + + +def wait_for_deployment_complete(deployment_name): + """ + Check if Deployment is running. + + Args: + deployment_name (str): the name of the Deployment. + + Returns: + True if Deployment is running, false otherwise + """ + complete = False + try: + response = api.read_namespaced_deployment(deployment_name, namespace) + status = response.status + if (status.unavailable_replicas is None and + (status.updated_replicas is None or + status.updated_replicas == response.spec.replicas) and + status.replicas == response.spec.replicas and + status.ready_replicas == response.spec.replicas and + status.observed_generation == response.metadata.generation): + log.info("Deployment %s is ready", deployment_name) + complete = True + else: + log.info("Deployment %s is NOT ready", deployment_name) + except ApiException as exc: + log.error("Exception when waiting for deployment status: %s\n", exc) + return complete + + +def wait_for_daemonset_complete(daemonset_name): + """ + Check if DaemonSet is running. + + Args: + daemonset_name (str): the name of the DaemonSet. + + Returns: + True if DaemonSet is running, false otherwise + """ + complete = False + try: + response = api_instance.read_namespaced_daemon_set( + daemonset_name, namespace) + status = response.status + if status.desired_number_scheduled == status.number_ready: + log.info("DaemonSet: %s/%s nodes ready --> %s is ready", + status.number_ready, status.desired_number_scheduled, + daemonset_name) + complete = True + else: + log.info("DaemonSet: %s/%s nodes ready --> %s is NOT ready", + status.number_ready, status.desired_number_scheduled, + daemonset_name) + except ApiException as exc: + log.error("Exception when waiting for DaemonSet status: %s\n", exc) + return complete + + +def is_ready(container_name): + """ + Check if a container is ready. + + For a container owned by a Job, it means the Job is complete. + Otherwise, it means the parent (Deployment, StatefulSet, DaemonSet) is + running with the right number of replicas + + Args: + container_name (str): the name of the container. + + Returns: + True if container is ready, false otherwise + """ + ready = False + log.info("Checking if %s is ready", container_name) + try: + response = coreV1Api.list_namespaced_pod(namespace=namespace, + watch=False) + for item in response.items: + # container_statuses can be None, which is non-iterable. + if item.status.container_statuses is None: + continue + for container in item.status.container_statuses: + if container.name == container_name: + name = read_name(item) + if item.metadata.owner_references[0].kind == "StatefulSet": + ready = wait_for_statefulset_complete(name) + elif item.metadata.owner_references[0].kind == "ReplicaSet": + deployment_name = get_deployment_name(name) + ready = wait_for_deployment_complete(deployment_name) + elif item.metadata.owner_references[0].kind == "Job": + ready = is_job_complete(name) + elif item.metadata.owner_references[0].kind == "DaemonSet": + ready = wait_for_daemonset_complete( + item.metadata.owner_references[0].name) + return ready + except ApiException as exc: + log.error("Exception when calling list_namespaced_pod: %s\n", exc) + return ready + + +def read_name(item): + """ + Return the name of the owner's item. + + Args: + item (str): the item. + + Returns: + the name of first owner's item + """ + return item.metadata.owner_references[0].name + + +def get_deployment_name(replicaset): + """ + Return the name of the Deployment owning the ReplicatSet. + + Args: + replicaset (str): the ReplicatSet. + + Returns: + the name of the Deployment owning the ReplicatSet + """ + api_response = api_instance.read_namespaced_replica_set_status(replicaset, + namespace) + deployment_name = read_name(api_response) + return deployment_name + + +DEF_TIMEOUT = 10 +DESCRIPTION = "Kubernetes container readiness check utility" +USAGE = "Usage: ready.py [-t <timeout>] -c <container_name> " \ + "[-c <container_name> ...]\n" \ + "where\n" \ + "<timeout> - wait for container readiness timeout in min, " \ + "default is " + str(DEF_TIMEOUT) + "\n" \ + "<container_name> - name of the container to wait for\n" + + +def main(argv): + """ + Checks if a container is ready or if a job is finished. + The check is done according to the name of the container, not the name of + its parent (Job, Deployment, StatefulSet, DaemonSet). + + Args: + argv: the command line + """ + # args are a list of container names + container_names = [] + timeout = DEF_TIMEOUT + try: + opts, _args = getopt.getopt(argv, "hc:t:", ["container-name=", + "timeout=", + "help"]) + for opt, arg in opts: + if opt in ("-h", "--help"): + print("{}\n\n{}".format(DESCRIPTION, USAGE)) + sys.exit() + elif opt in ("-c", "--container-name"): + container_names.append(arg) + elif opt in ("-t", "--timeout"): + timeout = float(arg) + except (getopt.GetoptError, ValueError) as exc: + print("Error parsing input parameters: {}\n".format(exc)) + print(USAGE) + sys.exit(2) + if container_names.__len__() == 0: + print("Missing required input parameter(s)\n") + print(USAGE) + sys.exit(2) + + for container_name in container_names: + timeout = time.time() + timeout * 60 + while True: + ready = is_ready(container_name) + if ready is True: + break + if time.time() > timeout: + log.warning("timed out waiting for '%s' to be ready", + container_name) + sys.exit(1) + else: + # spread in time potentially parallel execution in multiple + # containers + time.sleep(random.randint(5, 11)) + + +if __name__ == "__main__": + main(sys.argv[1:]) |