kubernetes/readiness/docker/init/ready.py

   1 #!/usr/bin/env python
   2 import getopt
   3 import logging
   4 import os
   5 import sys
   6 import time
   7 import random
   8
   9 from kubernetes import client
  10
  11 # extract env variables.
  12 namespace = os.environ['NAMESPACE']
  13 cert = os.environ['CERT']
  14 host = os.environ['KUBERNETES_SERVICE_HOST']
  15 token_path = os.environ['TOKEN']
  16
  17 with open(token_path, 'r') as token_file:
  18     token = token_file.read().replace('\n', '')
  19
  20 # setup logging
  21 log = logging.getLogger(__name__)
  22 handler = logging.StreamHandler(sys.stdout)
  23 handler.setFormatter(logging.Formatter('%(asctime)s - %(levelname)s - %(message)s'))
  24 handler.setLevel(logging.INFO)
  25 log.addHandler(handler)
  26 log.setLevel(logging.INFO)
  27
  28 configuration = client.Configuration()
  29 configuration.host = "https://" + host
  30 configuration.ssl_ca_cert = cert
  31 configuration.api_key['authorization'] = token
  32 configuration.api_key_prefix['authorization'] = 'Bearer'
  33 coreV1Api = client.CoreV1Api(client.ApiClient(configuration))
  34 api_instance=client.ExtensionsV1beta1Api(client.ApiClient(configuration))
  35 api = client.AppsV1beta1Api(client.ApiClient(configuration))
  36 batchV1Api = client.BatchV1Api(client.ApiClient(configuration))
  37
  38 def is_job_complete(job_name):
  39     complete = False
  40     log.info("Checking if " + job_name + "  is complete")
  41     response = ""
  42     try:
  43         response = batchV1Api.read_namespaced_job_status(job_name, namespace)
  44         if response.status.succeeded == 1:
  45             job_status_type = response.status.conditions[0].type
  46             if job_status_type == "Complete":
  47                 complete = True
  48                 log.info(job_name + " is complete")
  49             else:
  50                 log.info(job_name + " is not complete")
  51         else:
  52             log.info(job_name + " has not succeeded yet")
  53         return complete
  54     except Exception as e:
  55         log.error("Exception when calling read_namespaced_job_status: %s\n" % e)
  56
  57 def wait_for_statefulset_complete(statefulset_name):
  58     try:
  59         response = api.read_namespaced_stateful_set(statefulset_name, namespace)
  60         s = response.status
  61         if ( s.updated_replicas == response.spec.replicas and
  62                 s.replicas == response.spec.replicas and
  63                 s.ready_replicas == response.spec.replicas and
  64                 s.current_replicas == response.spec.replicas and
  65                 s.observed_generation == response.metadata.generation):
  66             log.info("Statefulset " + statefulset_name + "  is ready")
  67             return True
  68         else:
  69             log.info("Statefulset " + statefulset_name + "  is not ready")
  70         return False
  71     except Exception as e:
  72         log.error("Exception when waiting for Statefulset status: %s\n" % e)
  73
  74 def wait_for_deployment_complete(deployment_name):
  75     try:
  76         response = api.read_namespaced_deployment(deployment_name, namespace)
  77         s = response.status
  78         if ( s.unavailable_replicas == None and
  79                 s.updated_replicas == response.spec.replicas and
  80                 s.replicas == response.spec.replicas and
  81                 s.ready_replicas == response.spec.replicas and
  82                 s.observed_generation == response.metadata.generation):
  83             log.info("Deployment " + deployment_name + "  is ready")
  84             return True
  85         else:
  86             log.info("Deployment " + deployment_name + "  is not ready")
  87         return False
  88     except Exception as e:
  89         log.error("Exception when waiting for deployment status: %s\n" % e)
  90
  91 def is_ready(container_name):
  92     ready = False
  93     log.info("Checking if " + container_name + "  is ready")
  94     try:
  95         response = coreV1Api.list_namespaced_pod(namespace=namespace, watch=False)
  96         for i in response.items:
  97             # container_statuses can be None, which is non-iterable.
  98             if i.status.container_statuses is None:
  99                 continue
 100             for s in i.status.container_statuses:
 101                 if s.name == container_name:
 102                     if i.metadata.owner_references[0].kind  == "StatefulSet":
 103                         ready = wait_for_statefulset_complete(i.metadata.owner_references[0].name)
 104                     elif i.metadata.owner_references[0].kind == "ReplicaSet":
 105                         api_response = api_instance.read_namespaced_replica_set_status(i.metadata.owner_references[0].name, namespace)
 106                         ready = wait_for_deployment_complete(api_response.metadata.owner_references[0].name)
 107                     elif i.metadata.owner_references[0].kind == "Job":
 108                         ready = is_job_complete(i.metadata.owner_references[0].name)
 109
 110                     return ready
 111
 112                 else:
 113                     continue
 114         return ready
 115     except Exception as e:
 116         log.error("Exception when calling list_namespaced_pod: %s\n" % e)
 117
 118 DEF_TIMEOUT = 10
 119 DESCRIPTION = "Kubernetes container readiness check utility"
 120 USAGE = "Usage: ready.py [-t <timeout>] -c <container_name> [-c <container_name> ...]\n" \
 121         "where\n" \
 122         "<timeout> - wait for container readiness timeout in min, default is " + str(DEF_TIMEOUT) + "\n" \
 123         "<container_name> - name of the container to wait for\n"
 124
 125 def main(argv):
 126     # args are a list of container names
 127     container_names = []
 128     timeout = DEF_TIMEOUT
 129     try:
 130         opts, args = getopt.getopt(argv, "hc:t:", ["container-name=", "timeout=", "help"])
 131         for opt, arg in opts:
 132             if opt in ("-h", "--help"):
 133                 print("%s\n\n%s" % (DESCRIPTION, USAGE))
 134                 sys.exit()
 135             elif opt in ("-c", "--container-name"):
 136                 container_names.append(arg)
 137             elif opt in ("-t", "--timeout"):
 138                 timeout = float(arg)
 139     except (getopt.GetoptError, ValueError) as e:
 140         print("Error parsing input parameters: %s\n" % e)
 141         print(USAGE)
 142         sys.exit(2)
 143     if container_names.__len__() == 0:
 144         print("Missing required input parameter(s)\n")
 145         print(USAGE)
 146         sys.exit(2)
 147
 148     for container_name in container_names:
 149         timeout = time.time() + timeout * 60
 150         while True:
 151             ready = is_ready(container_name)
 152             if ready is True:
 153                 break
 154             elif time.time() > timeout:
 155                 log.warning("timed out waiting for '" + container_name + "' to be ready")
 156                 exit(1)
 157             else:
 158                 # spread in time potentially parallel execution in multiple containers
 159                 time.sleep(random.randint(5, 11))
 160
 161 if __name__ == "__main__":
 162     main(sys.argv[1:])
 163