Try to get ip from OpenStack EC2-compatible API (#684)
Try to get ip from OpenStack EC2-compatible API (#684)

OpenStack metadata service supports two sets of APIs: an OpenStack metadata API and an EC2-compatible API, The metadata service has an API that is compatible with version 2009-04-04 of the Amazon EC2 metadata service. We should try get instance ip from it first.
zalando/spilo,zalando/spilo,zalando/spilo