Changes to folder structure to allow multigroups and changed go mod name (#2105)

* Changed folder structure to allow multi group registration

* included actions.github.com directory for resources and controllers

* updated go module to actions/actions-runner-controller

* publish arc packages under actions-runner-controller

* Update charts/actions-runner-controller/docs/UPGRADING.md

Co-authored-by: Yusuke Kuoka <ykuoka@gmail.com>

controllers/actions.summerwind.net/runner_pod.go

@@ -0,0 +1,22 @@
+package controllers
+
+import corev1 "k8s.io/api/core/v1"
+
+// Force the runner pod managed by either RunnerDeployment and RunnerSet to have restartPolicy=Never.
+// See https://github.com/actions/actions-runner-controller/issues/1369 for more context.
+//
+// This is to prevent runner pods from stucking in Terminating when a K8s node disappeared along with the runnr pod and the runner container within it.
+//
+// Previously, we used restartPolicy of OnFailure, it turned wrong later, and therefore we now set Never.
+//
+// When the restartPolicy is OnFailure and the node disappeared, runner pods on the node seem to stuck in state.terminated==nil, state.waiting!=nil, and state.lastTerminationState!=nil,
+// and will ever become Running.
+// It's probably due to that the node onto which the pods have been scheduled will ever come back, hence the container restart attempt swill ever succeed,
+// the pods stuck waiting for successful restarts forever.
+//
+// By forcing runner pods to never restart, we hope there will be no chances of pods being stuck waiting.
+func forceRunnerPodRestartPolicyNever(pod *corev1.Pod) {
+	if pod.Spec.RestartPolicy != corev1.RestartPolicyNever {
+		pod.Spec.RestartPolicy = corev1.RestartPolicyNever
+	}
+}