Soam Vasani
0456df0d63
Create a Publisher interface. Refactor webhook publisher to satisfy that interface. Add some limited retries to webhook publisher.
132 lines
3.1 KiB
Go
132 lines
3.1 KiB
Go
/*
|
|
Copyright 2016 The Fission Authors.
|
|
|
|
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 kubewatcher
|
|
|
|
import (
|
|
"bytes"
|
|
"io/ioutil"
|
|
"log"
|
|
"net/http"
|
|
"reflect"
|
|
"time"
|
|
|
|
"k8s.io/client-go/1.5/pkg/watch"
|
|
)
|
|
|
|
type (
|
|
// A webhook publisher for a single URL. Satisifies the Publisher interface.
|
|
WebhookPublisher struct {
|
|
requestChannel chan *publishRequest
|
|
|
|
maxRetries int
|
|
retryDelay time.Duration
|
|
}
|
|
publishRequest struct {
|
|
url string
|
|
watchEvent watch.Event
|
|
retries int
|
|
retryDelay time.Duration
|
|
}
|
|
)
|
|
|
|
// The caller must make one of these per URL
|
|
func MakeWebhookPublisher() *WebhookPublisher {
|
|
p := &WebhookPublisher{
|
|
requestChannel: make(chan *publishRequest, 32), // buffered channel
|
|
|
|
// TODO make this configurable
|
|
maxRetries: 10,
|
|
retryDelay: 500 * time.Millisecond,
|
|
}
|
|
go p.svc()
|
|
return p
|
|
}
|
|
|
|
func (p *WebhookPublisher) Publish(watchEvent watch.Event, url string) {
|
|
p.requestChannel <- &publishRequest{
|
|
watchEvent: watchEvent,
|
|
url: url,
|
|
retries: p.maxRetries,
|
|
retryDelay: p.retryDelay,
|
|
}
|
|
}
|
|
|
|
func (p *WebhookPublisher) svc() {
|
|
for {
|
|
r := <-p.requestChannel
|
|
p.makeHttpRequest(r)
|
|
}
|
|
}
|
|
|
|
func (p *WebhookPublisher) makeHttpRequest(r *publishRequest) {
|
|
|
|
log.Printf("Making HTTP request to %v", r.url)
|
|
|
|
// Serialize the object
|
|
var buf bytes.Buffer
|
|
err := printKubernetesObject(r.watchEvent.Object, &buf)
|
|
if err != nil {
|
|
log.Println("Failed to serialize object: %v", err)
|
|
// TODO send a POST request indicating error
|
|
}
|
|
|
|
// Create request
|
|
req, err := http.NewRequest("POST", r.url, &buf)
|
|
if err != nil {
|
|
log.Printf("Failed to create request to %v", r.url)
|
|
// can't do anything more, drop the event.
|
|
return
|
|
}
|
|
|
|
// Event and object type aren't in the serialized object
|
|
req.Header.Add("Content-Type", "application/json")
|
|
req.Header.Add("X-Kubernetes-Event-Type", string(r.watchEvent.Type))
|
|
req.Header.Add("X-Kubernetes-Object-Type", reflect.TypeOf(r.watchEvent.Object).Name())
|
|
|
|
// Make the request
|
|
resp, err := http.DefaultClient.Do(req)
|
|
if err == nil && resp.StatusCode == 200 {
|
|
resp.Body.Close()
|
|
// all done.
|
|
return
|
|
}
|
|
|
|
// Log errors
|
|
if err != nil {
|
|
log.Printf("Request failed: %v", r)
|
|
} else if resp.StatusCode != 200 {
|
|
log.Printf("Request returned failure: %v", resp.StatusCode)
|
|
body, err := ioutil.ReadAll(resp.Body)
|
|
resp.Body.Close()
|
|
if err == nil {
|
|
log.Printf("request error: %v", body)
|
|
}
|
|
}
|
|
|
|
// Schedule a retry, or give up
|
|
r.retries--
|
|
if r.retries > 0 {
|
|
r.retryDelay *= time.Duration(2)
|
|
time.AfterFunc(r.retryDelay, func() {
|
|
p.requestChannel <- r
|
|
})
|
|
} else {
|
|
log.Printf("Final retry failed, giving up on %v", r.url)
|
|
// Event dropped
|
|
}
|
|
}
|