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
  34 def is_ready(container_name):
  35     ready = False
  36     log.info("Checking if " + container_name + "  is ready")
  37     try:
  38         response = coreV1Api.list_namespaced_pod(namespace=namespace, watch=False)
  39         for i in response.items:
  40             # container_statuses can be None, which is non-iterable.
  41             if i.status.container_statuses is None:
  42                 continue
  43             for s in i.status.container_statuses:
  44                 if i.metadata.owner_references[0].kind  == "StatefulSet":
  45                     if i.metadata.name == container_name:
  46                         ready = s.ready
  47                         if not ready:
  48                             log.info(container_name + " is not ready.")
  49                         else:
  50                             log.info(container_name + " is ready!")
  51                     else:
  52                         continue
  53                 elif s.name == container_name:
  54                     ready = s.ready
  55                     if not ready:
  56                         log.info(container_name + " is not ready.")
  57                     else:
  58                         log.info(container_name + " is ready!")
  59                 else:
  60                     continue
  61         return ready
  62     except Exception as e:
  63         log.error("Exception when calling list_namespaced_pod: %s\n" % e)
  64
  65
  66 DEF_TIMEOUT = 10
  67 DESCRIPTION = "Kubernetes container readiness check utility"
  68 USAGE = "Usage: ready.py [-t <timeout>] -c <container_name> [-c <container_name> ...]\n" \
  69         "where\n" \
  70         "<timeout> - wait for container readiness timeout in min, default is " + str(DEF_TIMEOUT) + "\n" \
  71         "<container_name> - name of the container to wait for\n"
  72
  73 def main(argv):
  74     # args are a list of container names
  75     container_names = []
  76     timeout = DEF_TIMEOUT
  77     try:
  78         opts, args = getopt.getopt(argv, "hc:t:", ["container-name=", "timeout=", "help"])
  79         for opt, arg in opts:
  80             if opt in ("-h", "--help"):
  81                 print("%s\n\n%s" % (DESCRIPTION, USAGE))
  82                 sys.exit()
  83             elif opt in ("-c", "--container-name"):
  84                 container_names.append(arg)
  85             elif opt in ("-t", "--timeout"):
  86                 timeout = float(arg)
  87     except (getopt.GetoptError, ValueError) as e:
  88         print("Error parsing input parameters: %s\n" % e)
  89         print(USAGE)
  90         sys.exit(2)
  91     if container_names.__len__() == 0:
  92         print("Missing required input parameter(s)\n")
  93         print(USAGE)
  94         sys.exit(2)
  95
  96     for container_name in container_names:
  97         timeout = time.time() + timeout * 60
  98         while True:
  99             ready = is_ready(container_name)
 100             if ready is True:
 101                 break
 102             elif time.time() > timeout:
 103                 log.warning("timed out waiting for '" + container_name + "' to be ready")
 104                 exit(1)
 105             else:
 106                 time.sleep(5)
 107
 108
 109 if __name__ == "__main__":
 110     main(sys.argv[1:])
 111