Return a boolean indicating whether given alias exists

    indices
        Single or multiple indices separated by comma, use _all to perform the operation on all indices.
    aliases
        Alias names separated by comma

    CLI example::

        salt myminion elasticsearch.alias_exists None testindex

def alias_exists(aliases, indices=None, hosts=None, profile=None):
    '''
    Return a boolean indicating whether given alias exists

    indices
        Single or multiple indices separated by comma, use _all to perform the operation on all indices.
    aliases
        Alias names separated by comma

    CLI example::

        salt myminion elasticsearch.alias_exists None testindex
    '''
    es = _get_instance(hosts, profile)
    try:
        return es.indices.exists_alias(name=aliases, index=indices)
    except elasticsearch.exceptions.NotFoundError:
        return False
    except elasticsearch.TransportError as e:
        raise CommandExecutionError("Cannot get alias {0} in index {1}, server returned code {2} with message {3}".format(aliases, indices, e.status_code, e.error))