#
# Copyright (c) 2016 NORDUnet A/S
# Copyright (c) 2018 SUNET
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from __future__ import absolute_import

import time
import atexit
import random
import subprocess

import etcd


class EtcdTemporaryInstance(object):
    """Singleton to manage a temporary Etcd instance

    Use this for testing purpose only. The instance is automatically destroyed
    at the end of the program.

    """
    _instance = None

    @classmethod
    def get_instance(cls):
        if cls._instance is None:
            cls._instance = cls()
            atexit.register(cls._instance.shutdown)
        return cls._instance

    def __init__(self):
        self._port = random.randint(40000, 50000)
        self._process = subprocess.Popen(['docker', 'run', '--rm',
                                          '-p', '{!s}:2379'.format(self._port),
                                          'docker.sunet.se/library/etcd:v2.2.5',
                                          '-advertise-client-urls', 'http://${HostIP}:2379',
                                          '-listen-client-urls', 'http://0.0.0.0:2379'],
                                         stdout=open('/tmp/etcd-temp.log', 'wb'),
                                         stderr=subprocess.STDOUT)

        for i in range(10):
            time.sleep(0.2)
            try:
                self._conn = etcd.Client('localhost', self._port)
                self._conn.stats  # Check connection
            except etcd.EtcdConnectionFailed:
                continue
            else:
                break
        else:
            self.shutdown()
            assert False, 'Cannot connect to the etcd test instance'

    @property
    def conn(self):
        return self._conn

    @property
    def host(self):
        return self._conn.host

    @property
    def port(self):
        return self._port

    def shutdown(self):
        if self._process:
            self._process.terminate()
            self._process.wait()
            self._process = None

@@ -3534,16 +3534,119 @@
 _process = None%0A
+        if EtcdTemporaryInstance._instance == self:%0A            EtcdTemporaryInstance._instance = None%0A

Reset the class variable if we get shutdown