mirror of
https://github.com/optim-enterprises-bv/kubernetes.git
synced 2025-10-31 10:18:13 +00:00
141 lines
4.3 KiB
Go
141 lines
4.3 KiB
Go
/*
|
|
Copyright 2014 The Kubernetes 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 genericapiserver
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"net/http"
|
|
|
|
"github.com/golang/glog"
|
|
|
|
"k8s.io/apiserver/pkg/healthz"
|
|
"k8s.io/kubernetes/pkg/client/restclient"
|
|
utilruntime "k8s.io/kubernetes/pkg/util/runtime"
|
|
)
|
|
|
|
// PostStartHookFunc is a function that is called after the server has started.
|
|
// It must properly handle cases like:
|
|
// 1. asynchronous start in multiple API server processes
|
|
// 2. conflicts between the different processes all trying to perform the same action
|
|
// 3. partially complete work (API server crashes while running your hook)
|
|
// 4. API server access **BEFORE** your hook has completed
|
|
// Think of it like a mini-controller that is super privileged and gets to run in-process
|
|
// If you use this feature, tag @deads2k on github who has promised to review code for anyone's PostStartHook
|
|
// until it becomes easier to use.
|
|
type PostStartHookFunc func(context PostStartHookContext) error
|
|
|
|
// PostStartHookContext provides information about this API server to a PostStartHookFunc
|
|
type PostStartHookContext struct {
|
|
// LoopbackClientConfig is a config for a privileged loopback connection to the API server
|
|
LoopbackClientConfig *restclient.Config
|
|
}
|
|
|
|
// PostStartHookProvider is an interface in addition to provide a post start hook for the api server
|
|
type PostStartHookProvider interface {
|
|
PostStartHook() (string, PostStartHookFunc, error)
|
|
}
|
|
|
|
type postStartHookEntry struct {
|
|
hook PostStartHookFunc
|
|
|
|
// done will be closed when the postHook is finished
|
|
done chan struct{}
|
|
}
|
|
|
|
// AddPostStartHook allows you to add a PostStartHook.
|
|
func (s *GenericAPIServer) AddPostStartHook(name string, hook PostStartHookFunc) error {
|
|
if len(name) == 0 {
|
|
return fmt.Errorf("missing name")
|
|
}
|
|
if hook == nil {
|
|
return nil
|
|
}
|
|
|
|
s.postStartHookLock.Lock()
|
|
defer s.postStartHookLock.Unlock()
|
|
|
|
if s.postStartHooksCalled {
|
|
return fmt.Errorf("unable to add %q because PostStartHooks have already been called", name)
|
|
}
|
|
if _, exists := s.postStartHooks[name]; exists {
|
|
return fmt.Errorf("unable to add %q because it is already registered", name)
|
|
}
|
|
|
|
// done is closed when the poststarthook is finished. This is used by the health check to be able to indicate
|
|
// that the poststarthook is finished
|
|
done := make(chan struct{})
|
|
s.AddHealthzChecks(postStartHookHealthz{name: "poststarthook/" + name, done: done})
|
|
s.postStartHooks[name] = postStartHookEntry{hook: hook, done: done}
|
|
|
|
return nil
|
|
}
|
|
|
|
// RunPostStartHooks runs the PostStartHooks for the server
|
|
func (s *GenericAPIServer) RunPostStartHooks() {
|
|
s.postStartHookLock.Lock()
|
|
defer s.postStartHookLock.Unlock()
|
|
s.postStartHooksCalled = true
|
|
|
|
context := PostStartHookContext{LoopbackClientConfig: s.LoopbackClientConfig}
|
|
|
|
for hookName, hookEntry := range s.postStartHooks {
|
|
go runPostStartHook(hookName, hookEntry, context)
|
|
}
|
|
}
|
|
|
|
func runPostStartHook(name string, entry postStartHookEntry, context PostStartHookContext) {
|
|
var err error
|
|
func() {
|
|
// don't let the hook *accidentally* panic and kill the server
|
|
defer utilruntime.HandleCrash()
|
|
err = entry.hook(context)
|
|
}()
|
|
// if the hook intentionally wants to kill server, let it.
|
|
if err != nil {
|
|
glog.Fatalf("PostStartHook %q failed: %v", name, err)
|
|
}
|
|
|
|
close(entry.done)
|
|
}
|
|
|
|
// postStartHookHealthz implements a healthz check for poststarthooks. It will return a "hookNotFinished"
|
|
// error until the poststarthook is finished.
|
|
type postStartHookHealthz struct {
|
|
name string
|
|
|
|
// done will be closed when the postStartHook is finished
|
|
done chan struct{}
|
|
}
|
|
|
|
var _ healthz.HealthzChecker = postStartHookHealthz{}
|
|
|
|
func (h postStartHookHealthz) Name() string {
|
|
return h.name
|
|
}
|
|
|
|
var hookNotFinished = errors.New("not finished")
|
|
|
|
func (h postStartHookHealthz) Check(req *http.Request) error {
|
|
select {
|
|
case <-h.done:
|
|
return nil
|
|
default:
|
|
return hookNotFinished
|
|
}
|
|
}
|