As part of #282, I have introduced some caching mechanism to avoid excessive GitHub API calls due to the autoscaling calculation involving GitHub API calls is executed on each Webhook event.
Apparently, it was saving the wrong value in the cache- The value was one after applying `HRA.Spec.{Max,Min}Replicas` so manual changes to {Max,Min}Replicas doesn't affect RunnerDeployment.Spec.Replicas until the cache expires. This isn't what I had wanted.
This patch fixes that, by changing the value being cached to one before applying {Min,Max}Replicas.
Additionally, I've also updated logging so that you observe which number was fetched from cache, and what number was suggested by either TotalNumberOfQueuedAndInProgressWorkflowRuns or PercentageRunnersBusy, and what was the final number used as the desired-replicas(after applying {Min,Max}Replicas).
Follow-up for #282
Since #392, the runner controller could have taken unexpectedly long time until it finally notices that the runner has been registered to GitHub. This patch fixes the issue, so that the controller will notice the successful registration in approximately 1 minute(hard-coded).
More concretely, let's say you had configured a long sync-period of like 10m, the runner controller could have taken approx 10m to notice the successful registration. The original expectation was 1m, because it was intended to recheck every 1m as implemented in #392. It wasn't working as such due to my misunderstanding in how requeueing work.
We occasionally encountered those errors while the underlying RunnerReplicaSet is being recreated/replaced on RunnerDeployment.Spec.Template update. It turned out to be due to that the RunnerDeployment controller was waiting for the runner pod becomes `Running`, intead of the new replacement runner to have registered to GitHub. This fixes that, by trying to Runner.Status.Phase to `Running` only after the runner in the runner pod appears to be registered.
A side-effect of this change is that runner controller would call more "ListRunners" GitHub Actions API. I've reviewed and improved the runner controller code and Runner CRD to make make the number of calls minimum. In most cases, ListRunners should be called only twice for each runner creation.
This allows you to trigger autoscaling depending on check_run names(i.e. actions job names). If you are willing to differentiate scale amount only for a specific job, or want to scale only on a specific job, try this.
PercentageRunnerBusy seems to have regressed since #355 due to that RunnerDeployment.Spec.Selector is empty by default and the HRA controller was using that empty selector to query runners, which somehow returned 0 runners. This fixes that by using the newly added automatic `runner-deployment-name` label for the default runner label and the selector, which avoids querying with empty selector.
Ref https://github.com/summerwind/actions-runner-controller/issues/377#issuecomment-795200205
We sometimes see that integration test fails due to runner replicas not meeting the expected number in a timely manner. After investigating a bit, this turned out to be due to that HRA updates on webhook-based autoscaler and HRA controller are conflicting. This changes the controllers to use Patch instead of Update to make conflicts less likely to happen.
I have also updated the hra controller to use Patch when updating RunnerDeployment, too.
Overall, these changes should make the webhook-based autoscaling more reliable due to less conflicts.
Similar to #348 for #346, but for HRA.Spec.CapacityReservations usually modified by the webhook-based autoscaler controller.
This patch tries to fix that by improving the webhook-based autoscaler controller to omit expired reservations on updating HRA spec.
`kubectl get horizontalrunnerautoscalers.actions.summerwind.dev` shows HRA.status.desiredReplicas as the DESIRED count. However the value had been not taking capacityReservations into account, which resulted in showing incorrect count when you used webhook-based autoscaler, or capacityReservations API directly. This fixes that.
The controller had been writing confusing messages like the below on missing scale target:
```
Found too many scale targets: It must be exactly one to avoid ambiguity. Either set WatchNamespace for the webhook-based autoscaler to let it only find HRAs in the namespace, or update Repository or Organization fields in your RunnerDeployment resources to fix the ambiguity.{"scaleTargets": ""}
```
This fixes that, while improving many kinds of messages written while reconcilation, so that the error message is more actionable.
We occasionally see logs like the below:
```
2021-02-24T02:48:26.769ZERRORFailed to update runner status{"runnerreplicaset": "testns-244ol/example-runnerdeploy-j5wzf", "error": "Operation cannot be fulfilled on runnerreplicasets.actions.summerwind.dev \"example-runnerdeploy-j5wzf\": the object has been modified; please apply your changes to the latest version and try again"}
github.com/go-logr/zapr.(*zapLogger).Error
/home/runner/go/pkg/mod/github.com/go-logr/zapr@v0.1.0/zapr.go:128
github.com/summerwind/actions-runner-controller/controllers.(*RunnerReplicaSetReconciler).Reconcile
/home/runner/work/actions-runner-controller/actions-runner-controller/controllers/runnerreplicaset_controller.go:207
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).reconcileHandler
/home/runner/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.4.0/pkg/internal/controller/controller.go:256
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem
/home/runner/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.4.0/pkg/internal/controller/controller.go:232
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).worker
/home/runner/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.4.0/pkg/internal/controller/controller.go:211
k8s.io/apimachinery/pkg/util/wait.JitterUntil.func1
/home/runner/go/pkg/mod/k8s.io/apimachinery@v0.0.0-20190913080033-27d36303b655/pkg/util/wait/wait.go:152
k8s.io/apimachinery/pkg/util/wait.JitterUntil
/home/runner/go/pkg/mod/k8s.io/apimachinery@v0.0.0-20190913080033-27d36303b655/pkg/util/wait/wait.go:153
k8s.io/apimachinery/pkg/util/wait.Until
/home/runner/go/pkg/mod/k8s.io/apimachinery@v0.0.0-20190913080033-27d36303b655/pkg/util/wait/wait.go:88
2021-02-24T02:48:26.769ZERRORcontroller-runtime.controllerReconciler error{"controller": "testns-244olrunnerreplicaset", "request": "testns-244ol/example-runnerdeploy-j5wzf", "error": "Operation cannot be fulfilled on runnerreplicasets.actions.summerwind.dev \"example-runnerdeploy-j5wzf\": the object has been modified; please apply your changes to the latest version and try again"}
github.com/go-logr/zapr.(*zapLogger).Error
/home/runner/go/pkg/mod/github.com/go-logr/zapr@v0.1.0/zapr.go:128
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).reconcileHandler
/home/runner/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.4.0/pkg/internal/controller/controller.go:258
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem
/home/runner/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.4.0/pkg/internal/controller/controller.go:232
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).worker
/home/runner/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.4.0/pkg/internal/controller/controller.go:211
k8s.io/apimachinery/pkg/util/wait.JitterUntil.func1
/home/runner/go/pkg/mod/k8s.io/apimachinery@v0.0.0-20190913080033-27d36303b655/pkg/util/wait/wait.go:152
k8s.io/apimachinery/pkg/util/wait.JitterUntil
/home/runner/go/pkg/mod/k8s.io/apimachinery@v0.0.0-20190913080033-27d36303b655/pkg/util/wait/wait.go:153
k8s.io/apimachinery/pkg/util/wait.Until
/home/runner/go/pkg/mod/k8s.io/apimachinery@v0.0.0-20190913080033-27d36303b655/pkg/util/wait/wait.go:88
```
which can be compacted into one-liner, without the useless stack trace, without double-logging the same error from the logger and the controller.
* if a runner pod starts up with an invalid token, it will go in an
infinite retry loop, appearing as RUNNING from the outside
* normally, this error situation is detected because no corresponding
runner objects exists in GitHub and the pod will get removed after
registration timeout
* if the GitHub runner object already existed before - e.g. because a
finalizer was not properly run as part of a partial Kubernetes crash,
the runner will always stay in a running mode, even updating the
registration token will not kill the problematic pod
* introducing RunnerOffline exception that can be handled in runner
controller and replicaset controller
* as runners are offline when a pod is completed and marked for restart,
only do additional restart checks if no restart was already decided,
making code a bit cleaner and saving GitHub API calls after each job
completion
I have heard from some user that they have hundred thousands of `status=completed` workflow runs in their repository which effectively blocked TotalNumberOfQueuedAndInProgressWorkflowRuns from working because of GitHub API rate limit due to excessive paginated requests.
This fixes that by separating list-workflow-runs calls to two - one for `queued` and one for `in_progress`, which can make the minimum API call from 1 to 2, but allows it to work regardless of number of remaining `completed` workflow runs.
* the reconciliation loop is often much faster than the runner startup,
so changing runner not found related messages to debug and also add the
possibility that the runner just needs more time
* errors.Is compares all members of a struct to return true which never
happened
* switched to type check instead of exact value check
* notRegistered was using double negation in if statement which lead to
unregistering runners after the registration timeout
* if a k8s node becomes unresponsive, the kube controller will soft
delete all pods after the eviction time (default 5 mins)
* as long as the node stays unresponsive, the pod will never leave the
last status and hence the runner controller will assume that everything
is fine with the pod and will not try to create new pods
* this can result in a situation where a horizontal autoscaler thinks
that none of its runners are currently busy and will not schedule any
further runners / pods, resulting in a broken runner deployment until the
runnerreplicaset is deleted or the node comes back online
* introducing a pod deletion timeout (1 minute) after which the runner
controller will try to reboot the runner and create a pod on a working
node
* use forceful deletion and requeue for pods that have been stuck for
more than one minute in terminating state
* gracefully handling race conditions if pod gets finally forcefully deleted within
This enhances the controller to recreate the runner pod if the corresponding runner has failed to register itself to GitHub within 10 minutes(currently hard-coded).
It should alleviate #288 in case the root cause is some kind of transient failures(network unreliability, GitHub down, temporarly compute resource shortage, etc).
Formerly you had to manually detect and delete such pods or even force-delete corresponding runners to unblock the controller.
Since this enhancement, the controller does the pod deletion automatically after 10 minutes after pod creation, which result in the controller create another pod that might work.
Ref #288
When we used `QueuedAndInProgressWorkflowRuns`-based autoscaling, it only fetched and considered only the first 30 workflow runs at the reconcilation time. This may have resulted in unreliable scaling behaviour, like scale-in/out not happening when it was expected.
* feat: HorizontalRunnerAutoscaler Webhook server
This introduces a Webhook server that responds GitHub `check_run`, `pull_request`, and `push` events by scaling up matched HorizontalRunnerAutoscaler by 1 replica. This allows you to immediately add "resource slack" for future GitHub Actions job runs, without waiting next sync period to add insufficient runners.
This feature is highly inspired by https://github.com/philips-labs/terraform-aws-github-runner. terraform-aws-github-runner can manage one set of runners per deployment, where actions-runner-controller with this feature can manage as many sets of runners as you declare with HorizontalRunnerAutoscaler and RunnerDeployment pairs.
On each GitHub event received, the webhook server queries repository-wide and organizational runners from the cluster and searches for the single target to scale up. The webhook server tries to match HorizontalRunnerAutoscaler.Spec.ScaleUpTriggers[].GitHubEvent.[CheckRun|Push|PullRequest] against the event and if it finds only one HRA, it is the scale target. If none or two or more targets are found for repository-wide runners, it does the same on organizational runners.
Changes:
* Fix integration test
* Update manifests
* chart: Add support for github webhook server
* dockerfile: Include github-webhook-server binary
* Do not import unversioned go-github
* Update README
* ensure that minReplicas <= desiredReplicas <= maxReplicas no matter what
* before this change, if the number of runners was much larger than the max number, the applied scale down factor might still result in a desired value > maxReplicas
* if for resource constraints in the cluster, runners would be permanently restarted, the number of runners could go up more than the reverse scale down factor until the next reconciliation round, resulting in a situation where the number of runners climbs up even though it should actually go down
* by checking whether the desiredReplicas is always <= maxReplicas, infinite scaling up loops can be prevented
One of the pod recreation conditions has been modified to use hash of runner spec, so that the controller does not keep restarting pods mutated by admission webhooks. This naturally allows us, for example, to use IRSA for EKS that requires its admission webhook to mutate the runner pod to have additional, IRSA-related volumes, volume mounts and env.
Resolves#200
Yusuke Kuoka
Brandon Kimbrough
Rob Whitby
Hiroshi Muraoka
Johannes Nicolai
Hidetake Iwata
Jesse Haka
Jonas Lergell
ZacharyBenamram