feat: add timeout when connect to rpc (#115)

* feat: add timeout when connect to rpc

* chore: fix golangci-lint

internal/app/app.go

@@ -56,7 +56,8 @@ func NewListener(c *cli.Context) (*listener.Listener, error) {
 	}
 	wsRPC := c.String(wsRPCFlag.Name)
 	l.Infow("Connect to node websocket rpc", "rpc", wsRPC)
-	wsEVMClient, err := evmclient.DialContext(context.Background(), wsRPC, httpClient)
+	wsEVMClient, err := evmclient.DialContextWithTimeout(
+		context.Background(), wsRPC, httpClient, defaultRequestTimeout)
 	if err != nil {
 		l.Errorw("Fail to connect to node", "rpc", wsRPC, "error", err)
 
@@ -65,7 +66,8 @@ func NewListener(c *cli.Context) (*listener.Listener, error) {
 
 	httpRPC := c.String(httpRPCFlag.Name)
 	l.Infow("Connect to node http rpc", "rpc", httpRPC)
-	httpEVMClient, err := evmclient.DialContext(context.Background(), httpRPC, httpClient)
+	httpEVMClient, err := evmclient.DialContextWithTimeout(
+		context.Background(), httpRPC, httpClient, defaultRequestTimeout)
 	if err != nil {
 		l.Errorw("Fail to connect to node", "rpc", httpRPC, "error", err)
 

pkg/evmclient/client.go

@@ -2,8 +2,10 @@ package evmclient
 
 import (
 	"context"
+	"errors"
 	"math/big"
 	"net/http"
+	"time"
 
 	"github.com/KyberNetwork/evmlistener/pkg/common"
 	"github.com/KyberNetwork/evmlistener/pkg/evmclient/ftmclient"
@@ -99,6 +101,36 @@ func DialContext(ctx context.Context, rawurl string, httpClient *http.Client) (*
 	return client, nil
 }
 
+func DialContextWithTimeout(
+	ctx context.Context,
+	rawurl string,
+	httpClient *http.Client,
+	timeout time.Duration,
+) (*Client, error) {
+	type dialContextResponse struct {
+		client *Client
+		err    error
+	}
+
+	ch := make(chan dialContextResponse, 1)
+	go func() {
+		client, err := DialContext(ctx, rawurl, httpClient)
+		ch <- dialContextResponse{
+			client: client,
+			err:    err,
+		}
+	}()
+
+	select {
+	case res := <-ch:
+		return res.client, res.err
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case <-time.After(timeout):
+		return nil, errors.New("timeout when dial RPC")
+	}
+}
+
 func (c *Client) ChainID(ctx context.Context) (*big.Int, error) {
 	return new(big.Int).SetUint64(c.chainID), nil
 }