How to use the flintrock.ec2.get_cluster function in Flintrock

Flintrock will configure new slaves based on information queried
    automatically from the master.
    """
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=[
            '--ec2-region',
            '--ec2-identity-file',
            '--ec2-user'],
        scope=locals())

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
        user = ec2_user
        identity_file = ec2_identity_file
        provider_options = {
            'min_root_ebs_size_gb': ec2_min_root_ebs_size_gb,
            'spot_price': ec2_spot_price,
            'tags': ec2_tags
        }
    else:
        raise UnsupportedProviderError(provider)

    if cluster.num_masters == 0:
        raise Error(
            "Cannot add slaves to cluster '{c}' since it does not "

Flintrock will return a non-zero code if any of the cluster nodes raises an error
    while running the command.
    """
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=[
            '--ec2-region',
            '--ec2-identity-file',
            '--ec2-user'],
        scope=locals())

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
        user = ec2_user
        identity_file = ec2_identity_file
    else:
        raise UnsupportedProviderError(provider)

    cluster.run_command_check()

    logger.info("Running command on {target}...".format(
        target="master only" if master_only else "cluster"))

    cluster.run_command(
        command=command,
        master_only=master_only,

def destroy(cli_context, cluster_name, assume_yes, ec2_region, ec2_vpc_id):
    """
    Destroy a cluster.
    """
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=['--ec2-region'],
        scope=locals())

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
    else:
        raise UnsupportedProviderError(provider)

    if not assume_yes:
        cluster.print()
        click.confirm(
            text="Are you sure you want to destroy this cluster?",
            abort=True)

    logger.info("Destroying {c}...".format(c=cluster.name))
    cluster.destroy()

"""
    Start an existing, stopped cluster.
    """
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=[
            '--ec2-region',
            '--ec2-identity-file',
            '--ec2-user'],
        scope=locals())

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
        user = ec2_user
        identity_file = ec2_identity_file
    else:
        raise UnsupportedProviderError(provider)

    cluster.start_check()
    logger.info("Starting {c}...".format(c=cluster_name))
    cluster.start(user=user, identity_file=identity_file)

option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=[
            '--ec2-region',
            '--ec2-identity-file',
            '--ec2-user'],
        scope=locals())

    # We assume POSIX for the remote path since Flintrock
    # only supports clusters running CentOS / Amazon Linux.
    if not posixpath.basename(remote_path):
        remote_path = posixpath.join(remote_path, os.path.basename(local_path))

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
        user = ec2_user
        identity_file = ec2_identity_file
    else:
        raise UnsupportedProviderError(provider)

    cluster.copy_file_check()

    if not assume_yes and not master_only:
        file_size_bytes = os.path.getsize(local_path)
        num_nodes = len(cluster.slave_ips) + 1  # TODO: cluster.num_nodes
        total_size_bytes = file_size_bytes * num_nodes

        if total_size_bytes > 10 ** 6:

def stop(cli_context, cluster_name, ec2_region, ec2_vpc_id, assume_yes):
    """
    Stop an existing, running cluster.
    """
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=['--ec2-region'],
        scope=locals())

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
    else:
        raise UnsupportedProviderError(provider)

    cluster.stop_check()

    if not assume_yes:
        cluster.print()
        click.confirm(
            text="Are you sure you want to stop this cluster?",
            abort=True)

    logger.info("Stopping {c}...".format(c=cluster_name))
    cluster.stop()

"""
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=[
            '--ec2-region',
            '--ec2-identity-file',
            '--ec2-user'],
        scope=locals())

    check_external_dependency('ssh')

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
        user = ec2_user
        identity_file = ec2_identity_file
    else:
        raise UnsupportedProviderError(provider)

    # TODO: Check that master up first and error out cleanly if not
    #       via ClusterInvalidState.
    cluster.login(user=user, identity_file=identity_file)

"""
    Remove slaves from an existing cluster.
    """
    provider = cli_context.obj['provider']

    option_requires(
        option='--provider',
        conditional_value='ec2',
        requires_all=[
            '--ec2-region',
            '--ec2-user',
            '--ec2-identity-file'],
        scope=locals())

    if provider == 'ec2':
        cluster = ec2.get_cluster(
            cluster_name=cluster_name,
            region=ec2_region,
            vpc_id=ec2_vpc_id)
        user = ec2_user
        identity_file = ec2_identity_file
    else:
        raise UnsupportedProviderError(provider)

    if num_slaves > cluster.num_slaves:
        logger.warning(
            "Warning: Cluster has {c} slave{cs}. "
            "You asked to remove {n} slave{ns}."
            .format(
                c=cluster.num_slaves,
                cs='' if cluster.num_slaves == 1 else 's',
                n=num_slaves,