Pass user context to pd.NewClientWithContext in NewClientWithOpts

[healthwaite]

When creating a new rawkv client in NewClientWithOpts we neglect to pass through the user's context to the pd client. This means any deadline/timeout set by the user is not adhered to. By default the call to pd.NewClientWithContext will retry for 100 attempts with a one second sleep between each attempt. This is annoying as a user if we want to set a shorter deadline. Fix the issue by calling pd.NewClientWithContext and passing through the user's context.

Using a modified version of example/rawkv/rawkv.go which sets the context deadline to 5 seconds and attempts to dial a bogus endpoint as an example. Before the fix:

$ time go run ./examples/rawkv/rawkv.go                                                                                                                                                                                                                            
[2023/10/16 16:30:35.202 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]                                                                                                                                                                                                                                                  
[2023/10/16 16:30:36.203 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]                                                                                                                                                                                                                                                  
... snipped ...
[2023/10/16 16:32:14.202 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
panic: [pd] failed to get cluster id

goroutine 1 [running]:
main.main()
        /home/areid/dev/client-go/examples/rawkv/rawkv.go:28 +0x565
exit status 2

real    1m40.452s
user    0m0.854s
sys     0m0.188s

After the fix:

$ time go run ./examples/rawkv/rawkv.go
[2023/10/16 16:33:06.881 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
[2023/10/16 16:33:07.881 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
[2023/10/16 16:33:08.882 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
[2023/10/16 16:33:09.882 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
[2023/10/16 16:33:10.881 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial tcp 127.0.0.1:2379: connect: connection refused\" target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
[2023/10/16 16:33:11.881 +01:00] [WARN] [pd_service_discovery.go:448] ["[pd] failed to get cluster id"] [url=http://127.0.0.1:2379] [error="[PD:client:ErrClientGetMember]error:rpc error: code = DeadlineExceeded desc = context deadline exceeded target:127.0.0.1:2379 status:TRANSIENT_FAILURE: error:rpc error: code = DeadlineExceeded desc = context deadline exceeded target:127.0.0.1:2379 status:TRANSIENT_FAILURE"]
panic: [pd] failed to get cluster id

goroutine 1 [running]:
main.main()
        /home/areid/dev/client-go/examples/rawkv/rawkv.go:32 +0x5bd
exit status 2

real    0m5.500s
user    0m0.839s
sys     0m0.339s