Given instance properties, return the instance id if it exists.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_ec2.get_id myinstance

def get_id(name=None, tags=None, region=None, key=None,
           keyid=None, profile=None, in_states=None, filters=None):

    '''
    Given instance properties, return the instance id if it exists.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_ec2.get_id myinstance

    '''
    instance_ids = find_instances(name=name, tags=tags, region=region, key=key,
                                  keyid=keyid, profile=profile, in_states=in_states,
                                  filters=filters)
    if instance_ids:
        log.info("Instance ids: %s", " ".join(instance_ids))
        if len(instance_ids) == 1:
            return instance_ids[0]
        else:
            raise CommandExecutionError('Found more than one instance '
                                        'matching the criteria.')
    else:
        log.warning('Could not find instance.')
        return None