[grpc-proxy] token expires, the new watch does not refresh the token.

[JKeita]

Bug report criteria

• This bug report is not security related, security issues should be disclosed privately via [email protected].
• This is not a support request, support requests should be raised in the etcd discussion forums.
• You have read the etcd bug reporting guidelines.
• Existing open issues along with etcd frequently asked questions have been checked and this is not a duplicate.

What happened?

When a token expires, creating a new watch will cause all other watches to become invalid.

What did you expect to happen?

Creating a watch and waiting for the token to expire after 10 seconds, and then creating another watch will cause all watches to become invalid.

How can we reproduce it (as minimally and precisely as possible)?

start etcd:
./etcd --listen-peer-urls http://0.0.0.0:2380 --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://0.0.0.0:2379 --auth-token-ttl 10

start grpc-proxy:
./etcd grpc-proxy start --endpoints=0.0.0.0:2379 --listen-addr=0.0.0.0:23790

test example:
`
package main

import (
"context"
"fmt"
clientv3 "go.etcd.io/etcd/client/v3"
"google.golang.org/grpc"
"time"
)

func main() {
cli, _ := clientv3.New(clientv3.Config{
Endpoints: []string{"centos7:23790"},
DialTimeout: time.Second * 5,
DialOptions: []grpc.DialOption{grpc.WithBlock()},
})
fmt.Println("start")
ctx, _ := context.WithCancel(context.Background())
ch := cli.Watch(ctx, "/key")
for resp := range ch {
if resp.Err() != nil {
fmt.Println(resp.Err())
}
for _, e := range resp.Events {
k, v := e.Kv.Key, e.Kv.Value
fmt.Println(k, v)
}
}
}

`

Anything else we need to know?

No response

Etcd version (please run commands below)

$ etcd --version
# paste output here
etcd Version: 3.5.4
Git SHA: 08407ff76
Go Version: go1.16.15
Go OS/Arch: linux/amd64

$ etcdctl version
# paste output here
etcdctl version: 3.5.4
API version: 3.5

Etcd configuration (command line flags or environment variables)

paste your configuration here

Etcd debug information (please run commands below, feel free to obfuscate the IP address or FQDN in the output)

$ etcdctl member list -w table
# paste output here

$ etcdctl --endpoints=<member list> endpoint status -w table
# paste output here

Relevant log output

No response

[CaojiamingAlan]

Please see #12385 and #14995.

I think currently you can fix this by the way mentioned in #14995: create a new client each time before watching.

[jmhbnz]

Discussed during sig-etcd triage meeting. @ahrtr is this a valid bug or should we close it given we have a workaround of opening new client before watch?

[ahrtr]

Duplicated to #15058