93 lines
1.5 KiB
Go
93 lines
1.5 KiB
Go
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package watch
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import (
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"bufio"
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"encoding/json"
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"net/http"
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"time"
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)
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// bodyWatcher scans the body of a request for chunks
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type bodyWatcher struct {
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results chan Event
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stop chan struct{}
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res *http.Response
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req *http.Request
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}
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// Changes returns the results channel
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func (wr *bodyWatcher) ResultChan() <-chan Event {
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return wr.results
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}
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// Stop cancels the request
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func (wr *bodyWatcher) Stop() {
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select {
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case <-wr.stop:
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return
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default:
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close(wr.stop)
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close(wr.results)
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}
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}
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func (wr *bodyWatcher) stream() {
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reader := bufio.NewReader(wr.res.Body)
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// ignore first few messages from stream,
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// as they are usually old.
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ignore := true
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go func() {
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<-time.After(time.Second)
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ignore = false
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}()
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go func() {
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// stop the watcher
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defer wr.Stop()
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for {
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// read a line
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b, err := reader.ReadBytes('\n')
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if err != nil {
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return
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}
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// ignore for the first second
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if ignore {
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continue
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}
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// send the event
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var event Event
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if err := json.Unmarshal(b, &event); err != nil {
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continue
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}
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wr.results <- event
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}
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}()
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}
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// NewBodyWatcher creates a k8s body watcher for
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// a given http request
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func NewBodyWatcher(req *http.Request, client *http.Client) (Watch, error) {
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stop := make(chan struct{})
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req.Cancel = stop
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res, err := client.Do(req)
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if err != nil {
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return nil, err
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}
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wr := &bodyWatcher{
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results: make(chan Event),
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stop: stop,
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req: req,
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res: res,
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}
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go wr.stream()
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return wr, nil
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}
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