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 formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
  24 handler.setFormatter(formatter)
  25 handler.setLevel(logging.INFO)
  26 log.addHandler(handler)
  27 log.setLevel(logging.INFO)
  28
  29 configuration = client.Configuration()
  30 configuration.host = "https://" + host
  31 configuration.ssl_ca_cert = cert
  32 configuration.api_key['authorization'] = token
  33 configuration.api_key_prefix['authorization'] = 'Bearer'
  34 coreV1Api = client.CoreV1Api(client.ApiClient(configuration))
  35 api_instance = client.ExtensionsV1beta1Api(client.ApiClient(configuration))
  36 api = client.AppsV1beta1Api(client.ApiClient(configuration))
  37 batchV1Api = client.BatchV1Api(client.ApiClient(configuration))
  38
  39
  40 def is_job_complete(job_name):
  41     complete = False
  42     log.info("Checking if " + job_name + "  is complete")
  43     try:
  44         response = batchV1Api.read_namespaced_job_status(job_name, namespace)
  45         if response.status.succeeded == 1:
  46             job_status_type = response.status.conditions[0].type
  47             if job_status_type == "Complete":
  48                 complete = True
  49                 log.info(job_name + " is complete")
  50             else:
  51                 log.info(job_name + " is not complete")
  52         else:
  53             log.info(job_name + " has not succeeded yet")
  54         return complete
  55     except Exception as e:
  56         log.error("Exception when calling read_namespaced_job_status: %s\n" % e)
  57
  58
  59 def wait_for_statefulset_complete(statefulset_name):
  60     try:
  61         response = api.read_namespaced_stateful_set(statefulset_name, namespace)
  62         s = response.status
  63         if (s.updated_replicas == response.spec.replicas and
  64                 s.replicas == response.spec.replicas and
  65                 s.ready_replicas == response.spec.replicas and
  66                 s.current_replicas == response.spec.replicas and
  67                 s.observed_generation == response.metadata.generation):
  68             log.info("Statefulset " + statefulset_name + "  is ready")
  69             return True
  70         else:
  71             log.info("Statefulset " + statefulset_name + "  is not ready")
  72         return False
  73     except Exception as e:
  74         log.error("Exception when waiting for Statefulset status: %s\n" % e)
  75
  76
  77 def wait_for_deployment_complete(deployment_name):
  78     try:
  79         response = api.read_namespaced_deployment(deployment_name, namespace)
  80         s = response.status
  81         if (s.unavailable_replicas is None and
  82                 ( s.updated_replicas is None or s.updated_replicas == response.spec.replicas ) and
  83                 s.replicas == response.spec.replicas and
  84                 s.ready_replicas == response.spec.replicas and
  85                 s.observed_generation == response.metadata.generation):
  86             log.info("Deployment " + deployment_name + "  is ready")
  87             return True
  88         else:
  89             log.info("Deployment " + deployment_name + "  is not ready")
  90         return False
  91     except Exception as e:
  92         log.error("Exception when waiting for deployment status: %s\n" % e)
  93
  94
  95 def is_ready(container_name):
  96     ready = False
  97     log.info("Checking if " + container_name + "  is ready")
  98     try:
  99         response = coreV1Api.list_namespaced_pod(namespace=namespace,
 100                                                  watch=False)
 101         for i in response.items:
 102             # container_statuses can be None, which is non-iterable.
 103             if i.status.container_statuses is None:
 104                 continue
 105             for s in i.status.container_statuses:
 106                 if s.name == container_name:
 107                     name = read_name(i)
 108                     if i.metadata.owner_references[0].kind == "StatefulSet":
 109                         ready = wait_for_statefulset_complete(name)
 110                     elif i.metadata.owner_references[0].kind == "ReplicaSet":
 111                         deployment_name = get_deployment_name(name)
 112                         ready = wait_for_deployment_complete(deployment_name)
 113                     elif i.metadata.owner_references[0].kind == "Job":
 114                         ready = is_job_complete(name)
 115
 116                     return ready
 117
 118                 else:
 119                     continue
 120         return ready
 121     except Exception as e:
 122         log.error("Exception when calling list_namespaced_pod: %s\n" % e)
 123
 124
 125 def read_name(item):
 126     return item.metadata.owner_reference[0].name
 127
 128
 129 def get_deployment_name(replicaset):
 130     api_response = api_instance.read_namespaced_replica_set_status(replicaset,
 131                                                                    namespace)
 132     deployment_name = read_name(api_response)
 133     return deployment_name
 134
 135
 136 DEF_TIMEOUT = 10
 137 DESCRIPTION = "Kubernetes container readiness check utility"
 138 USAGE = "Usage: ready.py [-t <timeout>] -c <container_name> " \
 139         "[-c <container_name> ...]\n" \
 140         "where\n" \
 141         "<timeout> - wait for container readiness timeout in min, " \
 142         "default is " + str(DEF_TIMEOUT) + "\n" \
 143         "<container_name> - name of the container to wait for\n"
 144
 145
 146 def main(argv):
 147     # args are a list of container names
 148     container_names = []
 149     timeout = DEF_TIMEOUT
 150     try:
 151         opts, args = getopt.getopt(argv, "hc:t:", ["container-name=",
 152                                                    "timeout=",
 153                                                    "help"])
 154         for opt, arg in opts:
 155             if opt in ("-h", "--help"):
 156                 print("%s\n\n%s" % (DESCRIPTION, USAGE))
 157                 sys.exit()
 158             elif opt in ("-c", "--container-name"):
 159                 container_names.append(arg)
 160             elif opt in ("-t", "--timeout"):
 161                 timeout = float(arg)
 162     except (getopt.GetoptError, ValueError) as e:
 163         print("Error parsing input parameters: %s\n" % e)
 164         print(USAGE)
 165         sys.exit(2)
 166     if container_names.__len__() == 0:
 167         print("Missing required input parameter(s)\n")
 168         print(USAGE)
 169         sys.exit(2)
 170
 171     for container_name in container_names:
 172         timeout = time.time() + timeout * 60
 173         while True:
 174             ready = is_ready(container_name)
 175             if ready is True:
 176                 break
 177             elif time.time() > timeout:
 178                 log.warning("timed out waiting for '" + container_name +
 179                             "' to be ready")
 180                 exit(1)
 181             else:
 182                 # spread in time potentially parallel execution in multiple
 183                 # containers
 184                 time.sleep(random.randint(5, 11))
 185
 186
 187 if __name__ == "__main__":
 188     main(sys.argv[1:])
 189