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kyverno/pkg/generate/controller.go
2020-03-17 17:23:18 -07:00

282 lines
8.7 KiB
Go

package generate
import (
"time"
"github.com/go-logr/logr"
kyverno "github.com/nirmata/kyverno/pkg/api/kyverno/v1"
kyvernoclient "github.com/nirmata/kyverno/pkg/client/clientset/versioned"
kyvernoinformer "github.com/nirmata/kyverno/pkg/client/informers/externalversions/kyverno/v1"
kyvernolister "github.com/nirmata/kyverno/pkg/client/listers/kyverno/v1"
dclient "github.com/nirmata/kyverno/pkg/dclient"
"github.com/nirmata/kyverno/pkg/event"
"github.com/nirmata/kyverno/pkg/policystatus"
"github.com/nirmata/kyverno/pkg/policyviolation"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/client-go/dynamic/dynamicinformer"
"k8s.io/client-go/informers"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/util/workqueue"
)
const (
maxRetries = 5
)
// Controller manages the life-cycle for Generate-Requests and applies generate rule
type Controller struct {
// dyanmic client implementation
client *dclient.Client
// typed client for kyverno CRDs
kyvernoClient *kyvernoclient.Clientset
// event generator interface
eventGen event.Interface
// handler for GR CR
syncHandler func(grKey string) error
// handler to enqueue GR
enqueueGR func(gr *kyverno.GenerateRequest)
// grStatusControl is used to update GR status
statusControl StatusControlInterface
// Gr that need to be synced
queue workqueue.RateLimitingInterface
// pLister can list/get cluster policy from the shared informer's store
pLister kyvernolister.ClusterPolicyLister
// grLister can list/get generate request from the shared informer's store
grLister kyvernolister.GenerateRequestNamespaceLister
// pSynced returns true if the Cluster policy store has been synced at least once
pSynced cache.InformerSynced
// grSynced returns true if the Generate Request store has been synced at least once
grSynced cache.InformerSynced
// policy violation generator
pvGenerator policyviolation.GeneratorInterface
// dyanmic sharedinformer factory
dynamicInformer dynamicinformer.DynamicSharedInformerFactory
//TODO: list of generic informers
// only support Namespaces for re-evalutation on resource updates
nsInformer informers.GenericInformer
policyStatusListener policystatus.Listener
log logr.Logger
}
//NewController returns an instance of the Generate-Request Controller
func NewController(
kyvernoclient *kyvernoclient.Clientset,
client *dclient.Client,
pInformer kyvernoinformer.ClusterPolicyInformer,
grInformer kyvernoinformer.GenerateRequestInformer,
eventGen event.Interface,
pvGenerator policyviolation.GeneratorInterface,
dynamicInformer dynamicinformer.DynamicSharedInformerFactory,
policyStatus policystatus.Listener,
log logr.Logger,
) *Controller {
c := Controller{
client: client,
kyvernoClient: kyvernoclient,
eventGen: eventGen,
pvGenerator: pvGenerator,
//TODO: do the math for worst case back off and make sure cleanup runs after that
// as we dont want a deleted GR to be re-queue
queue: workqueue.NewNamedRateLimitingQueue(workqueue.NewItemExponentialFailureRateLimiter(1, 30), "generate-request"),
dynamicInformer: dynamicInformer,
log: log,
policyStatusListener: policyStatus,
}
c.statusControl = StatusControl{client: kyvernoclient}
pInformer.Informer().AddEventHandlerWithResyncPeriod(cache.ResourceEventHandlerFuncs{
UpdateFunc: c.updatePolicy, // We only handle updates to policy
// Deletion of policy will be handled by cleanup controller
}, 2*time.Minute)
grInformer.Informer().AddEventHandlerWithResyncPeriod(cache.ResourceEventHandlerFuncs{
AddFunc: c.addGR,
UpdateFunc: c.updateGR,
DeleteFunc: c.deleteGR,
}, 2*time.Minute)
c.enqueueGR = c.enqueue
c.syncHandler = c.syncGenerateRequest
c.pLister = pInformer.Lister()
c.grLister = grInformer.Lister().GenerateRequests("kyverno")
c.pSynced = pInformer.Informer().HasSynced
c.grSynced = pInformer.Informer().HasSynced
//TODO: dynamic registration
// Only supported for namespaces
nsInformer := dynamicInformer.ForResource(client.DiscoveryClient.GetGVRFromKind("Namespace"))
c.nsInformer = nsInformer
c.nsInformer.Informer().AddEventHandlerWithResyncPeriod(cache.ResourceEventHandlerFuncs{
UpdateFunc: c.updateGenericResource,
}, 2*time.Minute)
return &c
}
func (c *Controller) updateGenericResource(old, cur interface{}) {
logger := c.log
curR := cur.(*unstructured.Unstructured)
grs, err := c.grLister.GetGenerateRequestsForResource(curR.GetKind(), curR.GetNamespace(), curR.GetName())
if err != nil {
logger.Error(err, "failed to get generate request CR for the resoource", "kind", curR.GetKind(), "name", curR.GetName(), "namespace", curR.GetNamespace())
return
}
// re-evaluate the GR as the resource was updated
for _, gr := range grs {
c.enqueueGR(gr)
}
}
func (c *Controller) enqueue(gr *kyverno.GenerateRequest) {
key, err := cache.MetaNamespaceKeyFunc(gr)
if err != nil {
c.log.Error(err, "failed to extract name")
return
}
c.queue.Add(key)
}
func (c *Controller) updatePolicy(old, cur interface{}) {
logger := c.log
oldP := old.(*kyverno.ClusterPolicy)
curP := cur.(*kyverno.ClusterPolicy)
if oldP.ResourceVersion == curP.ResourceVersion {
// Periodic resync will send update events for all known Namespace.
// Two different versions of the same replica set will always have different RVs.
return
}
logger.V(4).Info("updating policy", "name", oldP.Name)
// get the list of GR for the current Policy version
grs, err := c.grLister.GetGenerateRequestsForClusterPolicy(curP.Name)
if err != nil {
logger.Error(err, "failed to generate request for policy", "name", curP.Name)
return
}
// re-evaluate the GR as the policy was updated
for _, gr := range grs {
c.enqueueGR(gr)
}
}
func (c *Controller) addGR(obj interface{}) {
gr := obj.(*kyverno.GenerateRequest)
c.enqueueGR(gr)
}
func (c *Controller) updateGR(old, cur interface{}) {
oldGr := old.(*kyverno.GenerateRequest)
curGr := cur.(*kyverno.GenerateRequest)
if oldGr.ResourceVersion == curGr.ResourceVersion {
// Periodic resync will send update events for all known Namespace.
// Two different versions of the same replica set will always have different RVs.
return
}
// only process the ones that are in "Pending"/"Completed" state
// if the Generate Request fails due to incorrect policy, it will be requeued during policy update
if curGr.Status.State == kyverno.Failed {
return
}
c.enqueueGR(curGr)
}
func (c *Controller) deleteGR(obj interface{}) {
logger := c.log
gr, ok := obj.(*kyverno.GenerateRequest)
if !ok {
tombstone, ok := obj.(cache.DeletedFinalStateUnknown)
if !ok {
logger.Info("Couldn't get object from tombstone", "obj", obj)
return
}
_, ok = tombstone.Obj.(*kyverno.GenerateRequest)
if !ok {
logger.Info("tombstone contained object that is not a Generate Request CR", "obj", obj)
return
}
}
logger.Info("deleting generate request", "name", gr.Name)
// sync Handler will remove it from the queue
c.enqueueGR(gr)
}
//Run ...
func (c *Controller) Run(workers int, stopCh <-chan struct{}) {
logger := c.log
defer utilruntime.HandleCrash()
defer c.queue.ShutDown()
logger.Info("starting")
defer logger.Info("shutting down")
if !cache.WaitForCacheSync(stopCh, c.pSynced, c.grSynced) {
logger.Info("failed to sync informer cache")
return
}
for i := 0; i < workers; i++ {
go wait.Until(c.worker, time.Second, stopCh)
}
<-stopCh
}
// worker runs a worker thread that just dequeues items, processes them, and marks them done.
// It enforces that the syncHandler is never invoked concurrently with the same key.
func (c *Controller) worker() {
for c.processNextWorkItem() {
}
}
func (c *Controller) processNextWorkItem() bool {
key, quit := c.queue.Get()
if quit {
return false
}
defer c.queue.Done(key)
err := c.syncHandler(key.(string))
c.handleErr(err, key)
return true
}
func (c *Controller) handleErr(err error, key interface{}) {
logger := c.log
if err == nil {
c.queue.Forget(key)
return
}
if c.queue.NumRequeues(key) < maxRetries {
logger.Error(err, "failed to sync generate request", "key", key)
c.queue.AddRateLimited(key)
return
}
utilruntime.HandleError(err)
logger.Error(err, "Dropping generate request from the queue", "key", key)
c.queue.Forget(key)
}
func (c *Controller) syncGenerateRequest(key string) error {
logger := c.log
var err error
startTime := time.Now()
logger.Info("started sync", "key", key, "startTime", startTime)
defer func() {
logger.V(4).Info("finished sync", "key", key, "processingTime", time.Since(startTime))
}()
_, grName, err := cache.SplitMetaNamespaceKey(key)
if err != nil {
return err
}
gr, err := c.grLister.Get(grName)
if err != nil {
logger.Error(err, "failed to list generate requests")
return err
}
return c.processGR(gr)
}