Skip to content

Bug 1858403: Use client-go leader election to write less. #231

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
dgoodwin wants to merge 1 commit into from
Closed

Bug 1858403: Use client-go leader election to write less. #231

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions go.mod
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@ require (
github.com/go-bindata/go-bindata v3.1.2+incompatible
github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
github.com/golang/mock v1.4.3
github.com/google/uuid v1.1.1
github.com/openshift/api v0.0.0-20200728181127-fc1d675671df
github.com/openshift/build-machinery-go v0.0.0-20200713135615-1f43d26dccc7
github.com/openshift/client-go v0.0.0-20200722173614-5a1b0aaeff15
Expand Down
119 changes: 94 additions & 25 deletions pkg/cmd/operator/cmd.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -17,11 +17,16 @@ limitations under the License.
package cmd

import (
"context"
"flag"
golog "log"
"os"
"os/signal"
"syscall"
"time"

"github.com/golang/glog"
"github.com/google/uuid"
log "github.com/sirupsen/logrus"
"github.com/spf13/cobra"
"github.com/spf13/pflag"
Expand All @@ -30,8 +35,12 @@ import (
controller "github.com/openshift/cloud-credential-operator/pkg/operator"
"github.com/openshift/cloud-credential-operator/pkg/util"

metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/client-go/kubernetes"
_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
"k8s.io/client-go/tools/leaderelection"
"k8s.io/client-go/tools/leaderelection/resourcelock"
"sigs.k8s.io/controller-runtime/pkg/client/config"
"sigs.k8s.io/controller-runtime/pkg/manager"
"sigs.k8s.io/controller-runtime/pkg/runtime/signals"
Expand Down Expand Up @@ -67,35 +76,95 @@ func NewOperator() *cobra.Command {
log.WithError(err).Fatal("unable to set up client config")
}

// Create a new Cmd to provide shared dependencies and start components
log.Info("setting up manager")
mgr, err := manager.New(cfg, manager.Options{
MetricsBindAddress: ":2112",
LeaderElection: true,
LeaderElectionNamespace: minterv1.CloudCredOperatorNamespace,
LeaderElectionID: leaderElectionConfigMap,
})
if err != nil {
log.WithError(err).Fatal("unable to set up overall controller manager")
run := func(ctx context.Context) {
// Create a new Cmd to provide shared dependencies and start components
log.Info("setting up manager")
mgr, err := manager.New(cfg, manager.Options{
MetricsBindAddress: ":2112",
})
if err != nil {
log.WithError(err).Fatal("unable to set up overall controller manager")
}

log.Info("registering components")

// Setup Scheme for all resources
util.SetupScheme(mgr.GetScheme())

// Setup all Controllers
log.Info("setting up controller")
kubeconfigCommandLinePath := cmd.PersistentFlags().Lookup("kubeconfig").Value.String()
if err := controller.AddToManager(mgr, kubeconfigCommandLinePath); err != nil {
log.WithError(err).Fatal("unable to register controllers to the manager")
}

// Start the Cmd
log.Info("starting the cmd")
if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
log.WithError(err).Fatal("unable to run the manager")
}
}

log.Info("registering components")

// Setup Scheme for all resources
util.SetupScheme(mgr.GetScheme())

// Setup all Controllers
log.Info("setting up controller")
kubeconfigCommandLinePath := cmd.PersistentFlags().Lookup("kubeconfig").Value.String()
if err := controller.AddToManager(mgr, kubeconfigCommandLinePath); err != nil {
log.WithError(err).Fatal("unable to register controllers to the manager")
// Leader election code based on:
// https://github.com/kubernetes/kubernetes/blob/f7e3bcdec2e090b7361a61e21c20b3dbbb41b7f0/staging/src/k8s.io/client-go/examples/leader-election/main.go#L92-L154
// This gives us ReleaseOnCancel which is not presently exposed in controller-runtime.

// use a Go context so we can tell the leaderelection code when we want to step down
ctx, cancel := context.WithCancel(context.Background())
defer cancel()

// listen for interrupts or the Linux SIGTERM signal and cancel
// our context, which the leader election code will observe and
// step down
ch := make(chan os.Signal, 1)
signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
go func() {
<-ch
log.Info("received termination, signaling shutdown")
cancel()
}()

id := uuid.New().String()
leLog := log.WithField("id", id)
leLog.Info("generated leader election ID")

lock := &resourcelock.ConfigMapLock{
Copy link
Contributor

@staebler staebler Aug 5, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Is this a good time to switch to using a LeaseLock instead of a ConfigMapLock? Or is this more complicated due to needing to upgrade existing CCOs that would still be using a ConfigMapLock?

Copy link
Contributor Author

@dgoodwin dgoodwin Aug 5, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I wasn't totally aware how leaselock works, doesn't appear to be a resource in-cluster at least in 4.5 where I was running this. There is potential for some problems during upgrade though for sure, I'd vote to stay consistent for now.

ConfigMapMeta: metav1.ObjectMeta{
Namespace: minterv1.CloudCredOperatorNamespace,
Name: leaderElectionConfigMap,
},
Client: kubernetes.NewForConfigOrDie(cfg).CoreV1(),
LockConfig: resourcelock.ResourceLockConfig{
Identity: id,
},
}

// Start the Cmd
log.Info("starting the cmd")
if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
log.WithError(err).Fatal("unable to run the manager")
}
// start the leader election code loop
leaderelection.RunOrDie(ctx, leaderelection.LeaderElectionConfig{
Lock: lock,
ReleaseOnCancel: true,
LeaseDuration: 360 * time.Second,
RenewDeadline: 270 * time.Second,
RetryPeriod: 90 * time.Second,
Callbacks: leaderelection.LeaderCallbacks{
OnStartedLeading: func(ctx context.Context) {
run(ctx)
},
OnStoppedLeading: func() {
// we can do cleanup here if necessary
leLog.Infof("leader lost")
os.Exit(0)
},
OnNewLeader: func(identity string) {
if identity == id {
// We just became the leader
leLog.Info("became leader")
return
}
log.Infof("current leader: %s", identity)
},
},
})
},
}

Expand Down