def get_docker_client():
    # For Mac
    try:
        # Get boot2docker info (will fail if not Mac)
        process = ['boot2docker', 'info']
        p = subprocess.Popen(process, stdout=PIPE)
        boot2docker_info = json.loads(p.communicate()[0])

        # Defaults
        docker_host = ''
        docker_cert_path = ''
        docker_tls_verify = ''

        # Start the boot2docker VM if it is not already running
        if boot2docker_info['State'] != "running":
            print('Starting Boot2Docker VM:')
            # Start up the Docker VM
            process = ['boot2docker', 'start']
            subprocess.call(process)

        if ('DOCKER_HOST' not in os.environ) or ('DOCKER_CERT_PATH' not in os.environ) or ('DOCKER_TLS_VERIFY' not in os.environ):
            # Get environmental variable values
            process = ['boot2docker', 'shellinit']
            p = subprocess.Popen(process, stdout=PIPE)
            boot2docker_envs = p.communicate()[0].split()

            for env in boot2docker_envs:
                if 'DOCKER_HOST' in env:
                    docker_host = env.split('=')[1]
                elif 'DOCKER_CERT_PATH' in env:
                    docker_cert_path = env.split('=')[1]
                elif 'DOCKER_TLS_VERIFY' in env:
                    docker_tls_verify = env.split('=')[1]

            # Set environmental variables
            os.environ['DOCKER_TLS_VERIFY'] = docker_tls_verify
            os.environ['DOCKER_HOST'] = docker_host
            os.environ['DOCKER_CERT_PATH'] = docker_cert_path
        else:
            # Handle case when boot2docker is already running
            docker_host = os.environ['DOCKER_HOST'].split('=')[1]

        # Get the arguments form the environment
        client_kwargs = kwargs_from_env(assert_hostname=False)
        client_kwargs['version'] = MINIMUM_API_VERSION

        # Find the right version of the API by creating a DockerClient with the minimum working version
        # Then test to see if the Docker is running a later version than the minimum
        # See: https://github.com/docker/docker-py/issues/439
        version_client = DockerClient(**client_kwargs)
        client_kwargs['version'] = get_api_version(MAX_CLIENT_DOCKER_API_VERSION, version_client.version()['ApiVersion'])

        # Create Real Docker client
        docker_client = DockerClient(**client_kwargs)

        # Derive the host address only from string formatted: "tcp://<host>:<port>"
        docker_client.host = docker_host.split(':')[1].strip('//')

        return docker_client

    # For Linux
    except OSError:
        # Find the right version of the API by creating a DockerClient with the minimum working version
        # Then test to see if the Docker is running a later version than the minimum
        # See: https://github.com/docker/docker-py/issues/439
        version_client = DockerClient(base_url='unix://var/run/docker.sock', version=MINIMUM_API_VERSION)
        version = get_api_version(MAX_CLIENT_DOCKER_API_VERSION, version_client.version()['ApiVersion'])
        docker_client = DockerClient(base_url='unix://var/run/docker.sock', version=version)
        docker_client.host = DEFAULT_DOCKER_HOST

        return docker_client

    except:
        raise
Returns True if the given user has the specified permission.
dataset/ETHPy150Open tethysplatform/tethys/tethys_apps/cli/docker_commands.py/get_docker_client--crossover with--dataset/ETHPy150Open openstack/django_openstack_auth/openstack_auth/backend.py/KeystoneBackend.has_perm