// finishRequest makes a given resultFunc asynchronous and handles errors returned by the response.
// Any api.Status object returned is considered an "error", which interrupts the normal response flow.
func finishRequest(timeout time.Duration, fn resultFunc) (result runtime.Object, err error) {
// these channels need to be buffered to prevent the goroutine below from hanging indefinitely
// when the select statement reads something other than the one the goroutine sends on.
ch := make(chan runtime.Object, 1)
errCh := make(chan error, 1)
panicCh := make(chan interface{}, 1)
go func() {
// panics don't cross goroutine boundaries, so we have to handle ourselves
defer util.HandleCrash(func(panicReason interface{}) {
// Propagate to parent goroutine
panicCh <- panicReason
})
if result, err := fn(); err != nil {
errCh <- err
} else {
ch <- result
}
}()
select {
case result = <-ch:
if status, ok := result.(*unversioned.Status); ok {
return nil, errors.FromObject(status)
}
return result, nil
case err = <-errCh:
return nil, err
case p := <-panicCh:
panic(p)
case <-time.After(timeout):
return nil, errors.NewTimeoutError("request did not complete within allowed duration", 0)
}
}
// watchHandler watches w and keeps *resourceVersion up to date.
func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, resyncCh <-chan time.Time, stopCh <-chan struct{}) error {
start := time.Now()
eventCount := 0
// Stopping the watcher should be idempotent and if we return from this function there's no way
// we're coming back in with the same watch interface.
defer w.Stop()
loop:
for {
select {
case <-stopCh:
return errorStopRequested
case <-resyncCh:
return errorResyncRequested
case event, ok := <-w.ResultChan():
if !ok {
break loop
}
if event.Type == watch.Error {
return apierrs.FromObject(event.Object)
}
if e, a := r.expectedType, reflect.TypeOf(event.Object); e != nil && e != a {
util.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", r.name, e, a))
continue
}
meta, err := meta.Accessor(event.Object)
if err != nil {
util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
continue
}
newResourceVersion := meta.ResourceVersion()
switch event.Type {
case watch.Added:
r.store.Add(event.Object)
case watch.Modified:
r.store.Update(event.Object)
case watch.Deleted:
// TODO: Will any consumers need access to the "last known
// state", which is passed in event.Object? If so, may need
// to change this.
r.store.Delete(event.Object)
default:
util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
}
*resourceVersion = newResourceVersion
r.setLastSyncResourceVersion(newResourceVersion)
eventCount++
}
}
watchDuration := time.Now().Sub(start)
if watchDuration < 1*time.Second && eventCount == 0 {
glog.V(4).Infof("%s: Unexpected watch close - watch lasted less than a second and no items received", r.name)
return errors.New("very short watch")
}
glog.V(4).Infof("%s: Watch close - %v total %v items received", r.name, r.expectedType, eventCount)
return nil
}
// transformResponse converts an API response into a structured API object
func (r *Request) transformResponse(resp *http.Response, req *http.Request) Result {
var body []byte
if resp.Body != nil {
if data, err := ioutil.ReadAll(resp.Body); err == nil {
body = data
}
}
glog.V(8).Infof("Response Body: %s", string(body))
// Did the server give us a status response?
isStatusResponse := false
var status unversioned.Status
if err := r.codec.DecodeInto(body, &status); err == nil && status.Status != "" {
isStatusResponse = true
}
switch {
case resp.StatusCode == http.StatusSwitchingProtocols:
// no-op, we've been upgraded
case resp.StatusCode < http.StatusOK || resp.StatusCode > http.StatusPartialContent:
if !isStatusResponse {
return Result{err: r.transformUnstructuredResponseError(resp, req, body)}
}
return Result{err: errors.FromObject(&status)}
}
// If the server gave us a status back, look at what it was.
success := resp.StatusCode >= http.StatusOK && resp.StatusCode <= http.StatusPartialContent
if isStatusResponse && (status.Status != unversioned.StatusSuccess && !success) {
// "Failed" requests are clearly just an error and it makes sense to return them as such.
return Result{err: errors.FromObject(&status)}
}
return Result{
body: body,
statusCode: resp.StatusCode,
codec: r.codec,
}
}
// Stream formats and executes the request, and offers streaming of the response.
// Returns io.ReadCloser which could be used for streaming of the response, or an error
// Any non-2xx http status code causes an error. If we get a non-2xx code, we try to convert the body into an APIStatus object.
// If we can, we return that as an error. Otherwise, we create an error that lists the http status and the content of the response.
func (r *Request) Stream() (io.ReadCloser, error) {
if r.err != nil {
return nil, r.err
}
url := r.URL().String()
req, err := http.NewRequest(r.verb, url, nil)
if err != nil {
return nil, err
}
client := r.client
if client == nil {
client = http.DefaultClient
}
resp, err := client.Do(req)
if err != nil {
return nil, err
}
switch {
case (resp.StatusCode >= 200) && (resp.StatusCode < 300):
return resp.Body, nil
default:
// ensure we close the body before returning the error
defer resp.Body.Close()
// we have a decent shot at taking the object returned, parsing it as a status object and returning a more normal error
bodyBytes, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("%v while accessing %v", resp.Status, url)
}
if runtimeObject, err := r.codec.Decode(bodyBytes); err == nil {
statusError := errors.FromObject(runtimeObject)
if _, ok := statusError.(APIStatus); ok {
return nil, statusError
}
}
bodyText := string(bodyBytes)
return nil, fmt.Errorf("%s while accessing %v: %s", resp.Status, url, bodyText)
}
}