clientv3 can't be compiled with latest gRPC change

[gyuho]

# github.com/coreos/dbtester/vendor/github.com/coreos/etcd/clientv3

vendor/github.com/coreos/etcd/clientv3/client.go:309: oldconn.State undefined (type *grpc.ClientConn has no field or method State)
vendor/github.com/coreos/etcd/clientv3/client.go:311: oldconn.WaitForStateChange undefined (type *grpc.ClientConn has no field or method WaitForStateChange)

Currently we don't force users to use our gRPC dependencies, so this will happen.

I am creating this issue so we don't forget.

[heyitsanthony]

For the sake of completeness, I'll note the reason the code does that is so grpc won't queue the Close and keep some reconnection goroutine running (making the leak detector complain). Hopefully removing it won't cause any headaches...

[mkumatag]

I've also faced this issue while getting v3client

[root@jupiter-vm1164 src]# go get github.com/coreos/etcd/clientv3
# github.com/coreos/etcd/clientv3
github.com/coreos/etcd/clientv3/client.go:309: oldconn.State undefined (type *grpc.ClientConn has no field or method State)
github.com/coreos/etcd/clientv3/client.go:311: oldconn.WaitForStateChange undefined (type *grpc.ClientConn has no field or method WaitForStateChange)
[root@jupiter-vm1164 src]# 

Do we have any workaround for this?

[mkumatag]

part of commit - grpc/grpc-go@9c2d854#diff-e1550a73f5d25064c8b586ec68d81a64 they have created new structure called addrConn and moved State to getState and WaitForStateChange to waitForStateChange. So we might need to change the logic in the client file.

[heyitsanthony]

Fixed by #5583