130 lines
2.9 KiB
Go
130 lines
2.9 KiB
Go
// Copyright 2017 CoreOS, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package client
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import (
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"encoding/xml"
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"errors"
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"io"
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"net"
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"net/http"
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"time"
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"git.thisco.de/vbatts/go-omaha/omaha"
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)
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var (
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bodySizeError = &omahaError{
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Err: errors.New("http response exceeded 1MB"),
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Code: ExitCodeOmahaResponseInvalid,
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}
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bodyEmptyError = &omahaError{
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Err: errors.New("http response was empty"),
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Code: ExitCodeOmahaRequestEmptyResponseError,
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}
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// default parameters for expNetBackoff
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backoffStart = time.Second
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backoffTries = 7
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)
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// retries and exponentially backs off for temporary network errors
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func expNetBackoff(f func() error) error {
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var (
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backoff = backoffStart
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tries = backoffTries
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)
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for {
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err := f()
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tries--
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if tries <= 0 {
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return err
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}
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if neterr, ok := err.(net.Error); !ok || !neterr.Temporary() {
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return err
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}
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FuzzySleep(backoff, backoff)
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backoff *= 2
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}
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}
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// xml doesn't return the standard io.ErrUnexpectedEOF so check for both.
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func isUnexpectedEOF(err error) bool {
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if xerr, ok := err.(*xml.SyntaxError); ok {
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return xerr.Msg == "unexpected EOF"
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}
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return err == io.ErrUnexpectedEOF
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}
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// omahaError implements error and ErrorEvent for omaha requests/responses.
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type omahaError struct {
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Err error
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Code ExitCode
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}
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func (oe *omahaError) Error() string {
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return "omaha: request failed: " + oe.Err.Error()
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}
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func (oe *omahaError) ErrorEvent() *omaha.EventRequest {
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return NewErrorEvent(oe.Code)
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}
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// httpError implements error, net.Error, and ErrorEvent for http responses.
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type httpError struct {
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*http.Response
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}
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func (he *httpError) Error() string {
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return "http error: " + he.Status
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}
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func (he *httpError) ErrorEvent() *omaha.EventRequest {
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code := ExitCodeOmahaRequestError
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if he.StatusCode > 0 && he.StatusCode < 1000 {
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code = ExitCodeOmahaRequestHTTPResponseBase + ExitCode(he.StatusCode)
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}
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return NewErrorEvent(code)
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}
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func (he *httpError) Timeout() bool {
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switch he.StatusCode {
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case http.StatusRequestTimeout: // 408
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return true
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case http.StatusGatewayTimeout: // 504
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return true
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default:
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return false
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}
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}
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func (he *httpError) Temporary() bool {
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if he.Timeout() {
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return true
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}
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switch he.StatusCode {
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case http.StatusTooManyRequests: // 429
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return true
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case http.StatusInternalServerError: // 500
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return true
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case http.StatusBadGateway: // 502
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return true
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case http.StatusServiceUnavailable: // 503
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return true
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default:
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return false
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}
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}
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