This PR mainly did the following 3 things:
- Refactor NewEtcdKV API
- Add unittests for `kv/etcd/`, raise the coverage
up to 94%
- Correct some APIs from version to revision
The old NewEtcdKV() API took `clientv3.Client` as
one of the input, making everyone who using this API
had to create a new `clientv3.Client`. So there're a lot
of repeated codes everywhere.
Meanwhile, someplace didn't even check whether the
`clientv3.New()` returned error or not, and the old API
also didn't check whether the clientv3.Client was Nil.
This caused issue#6955.
Ectd's version and revision have nothing alike, they
represent different concepts, but our APIs kind of
mixed them all up. So I correct those APIs' names.
Resolves: #6955
Signed-off-by: yangxuan <xuan.yang@zilliz.com>
congqixia
XuanYang-cn
Cai Yudong
neza2017
godchen