kubernetes/readiness/docker/init/ready.py

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