89 lines
2.4 KiB
Go
89 lines
2.4 KiB
Go
// Copyright 2017 CoreOS, 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 client
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/xml"
|
|
"fmt"
|
|
"io"
|
|
"net/http"
|
|
"time"
|
|
|
|
"git.thisco.de/vbatts/go-omaha/omaha"
|
|
)
|
|
|
|
const (
|
|
defaultTimeout = 90 * time.Second
|
|
)
|
|
|
|
// httpClient extends the standard http.Client to support xml encoding
|
|
// and decoding as well as automatic retries on transient failures.
|
|
type httpClient struct {
|
|
http.Client
|
|
}
|
|
|
|
func newHTTPClient() *httpClient {
|
|
return &httpClient{http.Client{
|
|
Timeout: defaultTimeout,
|
|
}}
|
|
}
|
|
|
|
// doPost sends a single HTTP POST, returning a parsed omaha response.
|
|
func (hc *httpClient) doPost(url string, reqBody []byte) (*omaha.Response, error) {
|
|
resp, err := hc.Post(url, "text/xml; charset=utf-8", bytes.NewReader(reqBody))
|
|
if err != nil {
|
|
return nil, &omahaError{err, ExitCodeOmahaRequestError}
|
|
}
|
|
defer resp.Body.Close()
|
|
|
|
// A response over 1M in size is certainly bogus.
|
|
respBody := &io.LimitedReader{R: resp.Body, N: 1024 * 1024}
|
|
contentType := resp.Header.Get("Content-Type")
|
|
omahaResp, err := omaha.ParseResponse(contentType, respBody)
|
|
|
|
// Report a more sensible error if we truncated the body.
|
|
if isUnexpectedEOF(err) && respBody.N <= 0 {
|
|
err = bodySizeError
|
|
} else if err == io.EOF {
|
|
err = bodyEmptyError
|
|
} else if err != nil {
|
|
err = &omahaError{err, ExitCodeOmahaRequestXMLParseError}
|
|
}
|
|
|
|
// Prefer reporting HTTP errors over XML parsing errors.
|
|
if resp.StatusCode != http.StatusOK {
|
|
err = &httpError{resp}
|
|
}
|
|
|
|
return omahaResp, err
|
|
}
|
|
|
|
// Omaha encodes and sends an omaha request, retrying on any transient errors.
|
|
func (hc *httpClient) Omaha(url string, req *omaha.Request) (resp *omaha.Response, err error) {
|
|
buf := bytes.NewBufferString(xml.Header)
|
|
enc := xml.NewEncoder(buf)
|
|
if err := enc.Encode(req); err != nil {
|
|
return nil, fmt.Errorf("omaha: failed to encode request: %v", err)
|
|
}
|
|
|
|
expNetBackoff(func() error {
|
|
resp, err = hc.doPost(url, buf.Bytes())
|
|
return err
|
|
})
|
|
|
|
return resp, err
|
|
}
|