minio/cmd/rest/client.go

116 lines
3.4 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 rest
import (
"context"
"errors"
"io"
"io/ioutil"
"net/http"
"net/url"
"time"
xhttp "github.com/minio/minio/cmd/http"
)
// DefaultRESTTimeout - default RPC timeout is one minute.
const DefaultRESTTimeout = 1 * time.Minute
// NetworkError - error type in case of errors related to http/transport
// for ex. connection refused, connection reset, dns resolution failure etc.
// All errors returned by storage-rest-server (ex errFileNotFound, errDiskNotFound) are not considered to be network errors.
type NetworkError struct {
Err error
}
func (n *NetworkError) Error() string {
return n.Err.Error()
}
// Client - http based RPC client.
type Client struct {
httpClient *http.Client
httpIdleConnsCloser func()
url *url.URL
newAuthToken func() string
}
// URL query separator constants
const (
querySep = "?"
)
// CallWithContext - make a REST call with context.
func (c *Client) CallWithContext(ctx context.Context, method string, values url.Values, body io.Reader, length int64) (reply io.ReadCloser, err error) {
req, err := http.NewRequest(http.MethodPost, c.url.String()+method+querySep+values.Encode(), body)
if err != nil {
return nil, &NetworkError{err}
}
req = req.WithContext(ctx)
req.Header.Set("Authorization", "Bearer "+c.newAuthToken())
req.Header.Set("X-Minio-Time", time.Now().UTC().Format(time.RFC3339))
if length > 0 {
req.ContentLength = length
}
resp, err := c.httpClient.Do(req)
if err != nil {
c.httpClient.CloseIdleConnections()
return nil, &NetworkError{err}
}
if resp.StatusCode != http.StatusOK {
defer xhttp.DrainBody(resp.Body)
// Limit the ReadAll(), just in case, because of a bug, the server responds with large data.
b, err := ioutil.ReadAll(io.LimitReader(resp.Body, 4096))
if err != nil {
return nil, err
}
if len(b) > 0 {
return nil, errors.New(string(b))
}
return nil, errors.New(resp.Status)
}
return resp.Body, nil
}
// Call - make a REST call.
func (c *Client) Call(method string, values url.Values, body io.Reader, length int64) (reply io.ReadCloser, err error) {
ctx := context.Background()
return c.CallWithContext(ctx, method, values, body, length)
}
// Close closes all idle connections of the underlying http client
func (c *Client) Close() {
if c.httpIdleConnsCloser != nil {
c.httpIdleConnsCloser()
}
}
// NewClient - returns new REST client.
func NewClient(url *url.URL, newCustomTransport func() *http.Transport, newAuthToken func() string) (*Client, error) {
// Transport is exactly same as Go default in https://golang.org/pkg/net/http/#RoundTripper
// except custom DialContext and TLSClientConfig.
tr := newCustomTransport()
return &Client{
httpClient: &http.Client{Transport: tr},
httpIdleConnsCloser: tr.CloseIdleConnections,
url: url,
newAuthToken: newAuthToken,
}, nil
}