etcd when used in federated setups, currently
mandates that all clusters should have same
config.json, which is too restrictive and makes
federation a restrictive environment.
This change makes it apparent that each cluster
needs to be independently managed if necessary
from `mc admin info` command line.
Each cluster with in federation can have their
own root credentials and as well as separate
regions. This way buckets get further restrictions
and allows for root creds to be not common
across clusters/data centers.
Existing data in etcd gets migrated to backend
on each clusters, upon start. Once done
users can change their config entries
independently.
With CoreDNS now supporting etcdv3 as the DNS backend, we
can update our federation target to etcdv3. Users will now be
able to use etcdv3 server as the federation backbone.
Minio will update bucket data to etcdv3 and CoreDNS can pick
that data up and serve it as bucket style DNS path.
This PR adds CopyObject support for objects residing in buckets
in different Minio instances (where Minio instances are part of
a federated setup).
Also, added support for multiple Minio domain IPs. This is required
for distributed deployments, where one deployment may have multiple
nodes, each with a different public IP.
Buckets already present on a Minio server before it joins a
bucket federated deployment will now be added to etcd during
startup. In case of a bucket name collision, admin is informed
via Minio server console message.
Added configuration migration for configuration stored in etcd
backend.
Also, environment variables are updated and ListBucket path style
request is no longer forwarded.
