91b60ac595
Add a method to retrieve logs from Kubernetes Pod Change-Id: I02e59c164881566d4c2b0d5decbe9eb0f3f30d34
118 lines
4.9 KiB
Python
118 lines
4.9 KiB
Python
# Copyright 2018 AT&T Intellectual Property. All other rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import logging
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from kubernetes import client, config
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from kubernetes.client.rest import ApiException
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LOG = logging.getLogger(__name__)
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_NOT_FOUND_MSG_FMT = ("No matching pods found for namespace: {}"
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" pod: {} container: {}")
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class K8sLoggingException(Exception):
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""" We do not really want the workflow to terminate due to logs
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retrieval issues and hence we will have another Exception
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handling class to handle this."""
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pass
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def get_pod_logs(pod_name_pattern, namespace, container, since_seconds):
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"""This function retrieves the logs of the kubernetes pod
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:param pod_name_pattern: Pattern of Pods name, e.g. 'drydock-api' if
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we want to check the logs of the Drydock API
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pods. Note that we are parsing pattern as
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there are usually multiple pods present (for
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redundancy purposes) and we will want to show
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the logs of all the relevant pods.
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:param namespace: Namespace where Pods reside
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:param container: The container for which to stream logs. Defaults
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to only container if there is one container in
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the pod.
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:param since_seconds: A relative time in seconds before the current
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time from which to show logs. If this value
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precedes the time a pod was started, only logs
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since the pod start will be returned. If this
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value is in the future, no logs will be returned.
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Example::
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from get_k8s_logs import get_pod_logs
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# Calls function to retrieve logs
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get_pod_logs('airflow-worker', 'ucp', 'airflow-worker', 3600)
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"""
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# Note that we are using 'in_cluster_config'
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config.load_incluster_config()
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v1 = client.CoreV1Api()
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# Initialize variable
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pods_list = []
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# Retrieve names of pods
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try:
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ret = v1.list_namespaced_pod(namespace=namespace,
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watch=False)
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except ApiException as e:
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LOG.error(e)
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msg = ("Caught %s while trying to retrieve namespaced pods from K8s"
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" API. Details: %s" % (e.__class__.__name__, e))
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raise K8sLoggingException(msg)
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if ret:
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for i in ret.items:
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if pod_name_pattern in i.metadata.name:
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pods_list.append(i.metadata.name)
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else:
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raise K8sLoggingException(_NOT_FOUND_MSG_FMT.format(namespace,
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pod_name_pattern,
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container))
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if pods_list:
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LOG.info("The following Pods matched the requested pattern %s: %s",
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pod_name_pattern, ", ".join(pods_list))
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else:
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raise K8sLoggingException(_NOT_FOUND_MSG_FMT.format(namespace,
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pod_name_pattern,
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container))
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# Retrieve logs from pod
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for pod in pods_list:
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try:
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# Note that the kwarg 'pretty' takes on string value and will
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# ensure that the output is pretty printed if set 'true'.
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pod_logs = v1.read_namespaced_pod_log(name=pod,
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namespace=namespace,
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container=container,
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pretty='true',
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since_seconds=since_seconds)
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except ApiException as e:
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LOG.error(e)
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msg = ("Caught %s while trying to read logs from namespaced pod=%s"
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", namespace=%s, container=%s using the k8s API. Details: "
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"%s" % (e.__class__.__name__, pod, namespace, container, e))
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raise K8sLoggingException(msg)
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LOG.info("\n\n================= Logs for container %s of pods %s in"
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" namespace %s =================\n\n",
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container, pod, namespace)
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LOG.info(pod_logs)
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LOG.info("\n\n================= End Logs for %s =================\n\n",
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pod)
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