/
controller.go
167 lines (137 loc) · 4.23 KB
/
controller.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/*
Copyright 2019 The Jetstack cert-manager contributors.
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 controller
import (
"context"
"fmt"
"sync"
"time"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/util/workqueue"
logf "github.com/jetstack/cert-manager/pkg/logs"
"github.com/jetstack/cert-manager/pkg/metrics"
)
type runFunc func(context.Context)
type runDurationFunc struct {
fn runFunc
duration time.Duration
}
type queueingController interface {
Register(*Context) (workqueue.RateLimitingInterface, []cache.InformerSynced, error)
ProcessItem(ctx context.Context, key string) error
}
func NewController(
ctx context.Context,
name string,
metrics *metrics.Metrics,
syncFunc func(ctx context.Context, key string) error,
mustSync []cache.InformerSynced,
runDurationFuncs []runDurationFunc,
queue workqueue.RateLimitingInterface,
) Interface {
return &controller{
ctx: ctx,
name: name,
metrics: metrics,
syncHandler: syncFunc,
mustSync: mustSync,
runDurationFuncs: runDurationFuncs,
queue: queue,
}
}
type controller struct {
// ctx is the root golang context for the controller
ctx context.Context
// name is the name for this controller
name string
// the function that should be called when an item is popped
// off the workqueue
syncHandler func(ctx context.Context, key string) error
// mustSync is a slice of informers that must have synced before
// this controller can start
mustSync []cache.InformerSynced
// a set of functions that will be called just after controller initialisation, once.
runFirstFuncs []runFunc
// a set of functions that should be called every duration.
runDurationFuncs []runDurationFunc
// queue is a reference to the queue used to enqueue resources
// to be processed
queue workqueue.RateLimitingInterface
// metrics is used to expose Prometheus, shared by all controllers
metrics *metrics.Metrics
}
// Run starts the controller loop
func (c *controller) Run(workers int, stopCh <-chan struct{}) error {
ctx, cancel := context.WithCancel(c.ctx)
defer cancel()
log := logf.FromContext(ctx)
log.Info("starting control loop")
// wait for all the informer caches we depend on are synced
if !cache.WaitForCacheSync(stopCh, c.mustSync...) {
return fmt.Errorf("error waiting for informer caches to sync")
}
var wg sync.WaitGroup
for i := 0; i < workers; i++ {
wg.Add(1)
// TODO (@munnerz): make time.Second duration configurable
go wait.Until(func() {
defer wg.Done()
c.worker(ctx)
}, time.Second, stopCh)
}
for _, f := range c.runFirstFuncs {
f(ctx)
}
for _, f := range c.runDurationFuncs {
go wait.Until(func() { f.fn(ctx) }, f.duration, stopCh)
}
<-stopCh
log.Info("shutting down queue as workqueue signaled shutdown")
c.queue.ShutDown()
log.V(logf.DebugLevel).Info("waiting for workers to exit...")
wg.Wait()
log.V(logf.DebugLevel).Info("workers exited")
return nil
}
func (b *controller) worker(ctx context.Context) {
log := logf.FromContext(b.ctx)
log.V(logf.DebugLevel).Info("starting worker")
for {
obj, shutdown := b.queue.Get()
if shutdown {
break
}
var key string
// use an inlined function so we can use defer
func() {
defer b.queue.Done(obj)
var ok bool
if key, ok = obj.(string); !ok {
return
}
log := log.WithValues("key", key)
log.Info("syncing item")
// Increase sync count for this controller
b.metrics.IncrementSyncCallCount(b.name)
if err := b.syncHandler(ctx, key); err != nil {
log.Error(err, "re-queuing item due to error processing")
b.queue.AddRateLimited(obj)
return
}
log.Info("finished processing work item")
b.queue.Forget(obj)
}()
}
log.V(logf.DebugLevel).Info("exiting worker loop")
}