Cannot use *grpcpool.ClientConn as type *grpc.ClientConn

[wakenmeng]

> go build
./main.go:31:24: cannot use conn (type *grpcpool.ClientConn) as type *grpc.ClientConn in argument to testproto.NewFooClient

Above incompatible types error occured when build. Here's the code:
go version go1.11.5 linux/amd64

package main

import (
	"context"
	"github.com/processout/grpc-go-pool"
	"google.golang.org/grpc"
	"log"
	pb "/local/path/proto"
	"time"
)

func newConnection() (*grpc.ClientConn, error) {
	conn, err := grpc.Dial("127.0.0.1:10000", grpc.WithInsecure())
	if err != nil {
		log.Fatal("Connect to service failed. ", err)
		return nil, err
	}
	log.Println("Connected to service")
	return conn, nil
}

var connPool *grpcpool.Pool

func InitPool() (err error) {
	connPool, err = grpcpool.New(newConnection, 5, 5, time.Second)
	return
}

func main() {
        InitPool()
	conn, _ := connPool.Get(context.Background())
	cli := pb.NewFooClient(conn)
	log.Println("done")
}

[manuel-huez]

Hi @wakenmeng

I'm not sure to understand your issue- could you please give me more context in what you're trying to achieve?

The NewFooClient function seems to only accept *grpc.ClientConn (not an interface either), so to me this is expected behavior that the compiler complains about the type of the pool being *grpcpool.ClientConn. Perhaps you could change that function arguments to take the type you're looking for?

[wakenmeng]

I read the test code and found out that I misuse the library. Sorry that I forgot to close this issue, I'm closing it. thanks for your reply @manuel-huez.

[magv96]

@wakenmeng I am having the same issue and was wondering if you could elaborate on how you resolved this. Thank you so much!

[wakenmeng]

@magv96 sure. The grpcPoolConn from pool.Get(ctx) has a member *grpc.ClientConn, which is type grpc.ClientConn. Here's the defination
So to use it with grpc:

pool := InitPool()
conn, _ := pool.Get(context.Background())
grpcClient := pb.NewFooClient(conn.ClientConn) // Here, use conn.ClientConn, which is grpc.ClientConn type.
grpcClient.DoTheCall()

by the way, if there's an example file will be helpful.