minio/cmd/rpc/client.go

129 lines
3.3 KiB
Go

/*
* Minio Cloud Storage, (C) 2018 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rpc
import (
"bytes"
"context"
"crypto/tls"
"encoding/gob"
"errors"
"fmt"
"net"
"net/http"
"reflect"
"time"
xhttp "github.com/minio/minio/cmd/http"
xnet "github.com/minio/minio/pkg/net"
)
// DefaultRPCTimeout - default RPC timeout is one minute.
const DefaultRPCTimeout = 1 * time.Minute
// Client - http based RPC client.
type Client struct {
httpClient *http.Client
serviceURL *xnet.URL
}
// Call - calls service method on RPC server.
func (client *Client) Call(serviceMethod string, args, reply interface{}) error {
replyKind := reflect.TypeOf(reply).Kind()
if replyKind != reflect.Ptr {
return fmt.Errorf("rpc reply must be a pointer type, but found %v", replyKind)
}
data, err := gobEncode(args)
if err != nil {
return err
}
callRequest := CallRequest{
Method: serviceMethod,
ArgBytes: data,
}
var buf bytes.Buffer
if err = gob.NewEncoder(&buf).Encode(callRequest); err != nil {
return err
}
response, err := client.httpClient.Post(client.serviceURL.String(), "", &buf)
if err != nil {
return err
}
defer response.Body.Close()
if response.StatusCode != http.StatusOK {
return fmt.Errorf("%v rpc call failed with error code %v", serviceMethod, response.StatusCode)
}
var callResponse CallResponse
if err := gob.NewDecoder(response.Body).Decode(&callResponse); err != nil {
return err
}
if callResponse.Error != "" {
return errors.New(callResponse.Error)
}
return gobDecode(callResponse.ReplyBytes, reply)
}
// Close - does nothing and presents for interface compatibility.
func (client *Client) Close() error {
return nil
}
func newCustomDialContext(timeout time.Duration) func(ctx context.Context, network, addr string) (net.Conn, error) {
return func(ctx context.Context, network, addr string) (net.Conn, error) {
dialer := &net.Dialer{
Timeout: timeout,
KeepAlive: timeout,
DualStack: true,
}
conn, err := dialer.DialContext(ctx, network, addr)
if err != nil {
return nil, err
}
return xhttp.NewTimeoutConn(conn, timeout, timeout), nil
}
}
// NewClient - returns new RPC client.
func NewClient(serviceURL *xnet.URL, tlsConfig *tls.Config, timeout time.Duration) *Client {
return &Client{
httpClient: &http.Client{
// Transport is exactly same as Go default in https://golang.org/pkg/net/http/#RoundTripper
// except custom DialContext and TLSClientConfig.
Transport: &http.Transport{
Proxy: http.ProxyFromEnvironment,
DialContext: newCustomDialContext(timeout),
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
TLSClientConfig: tlsConfig,
},
},
serviceURL: serviceURL,
}
}