Previous change logs can be found at CHANGELOG-3.x.
Planned breaking changes.
See code changes and v4.0 upgrade guide for any breaking changes. Again, before running upgrades from any previous release, please make sure to read change logs below and v4.0 upgrade guide.
/health endpoint output.
{"health":"true"}.{"health":true}.kubectl get componentstatuses command.etcd --proxy* flags; no more v2 proxy.etcdctl backup command.clientv3.Client.KeepAlive(ctx context.Context, id LeaseID) (<-chan *LeaseKeepAliveResponse, error) is now clientv4.Client.KeepAlive(ctx context.Context, id LeaseID) <-chan *LeaseKeepAliveResponse.
Watch, KeepAlive does not return errors.KeepAlive call.github.com/coreos/client to github.com/coreos/clientv2.