* feat: RunnerSet backed by StatefulSet
Unlike a runner deployment, a runner set can manage a set of stateful runners by combining a statefulset and an admission webhook that mutates statefulset-managed pods with required envvars and registration tokens.
Resolves#613
Ref #612
* Upgrade controller-runtime to 0.9.0
* Bump Go to 1.16.x following controller-runtime 0.9.0
* Upgrade kubebuilder to 2.3.2 for updated etcd and apiserver following local setup
* Fix startup failure due to missing LeaderElectionID
* Fix the issue that any pods become unable to start once actions-runner-controller got failed after the mutating webhook has been registered
* Allow force-updating statefulset
* Fix runner container missing work and certs-client volume mounts and DOCKER_HOST and DOCKER_TLS_VERIFY envvars when dockerdWithinRunner=false
* Fix runnerset-controller not applying statefulset.spec.template.spec changes when there were no changes in runnerset spec
* Enable running acceptance tests against arbitrary kind cluster
* RunnerSet supports non-ephemeral runners only today
* fix: docker-build from root Makefile on intel mac
* fix: arch check fixes for mac and ARM
* ci: aligning test data format and patching checks
* fix: removing namespace in test data
* chore: adding more ignores
* chore: removing leading space in shebang
* Re-add metrics to org hra testdata
* Bump cert-manager to v1.1.1 and fix deploy.sh
Co-authored-by: toast-gear <15716903+toast-gear@users.noreply.github.com>
Co-authored-by: Callum James Tait <callum.tait@photobox.com>
This is an attempt to support scaling from/to zero.
The basic idea is that we create a one-off "registration-only" runner pod on RunnerReplicaSet being scaled to zero, so that there is one "offline" runner, which enables GitHub Actions to queue jobs instead of discarding those.
GitHub Actions seems to immediately throw away the new job when there are no runners at all. Generally, having runners of any status, `busy`, `idle`, or `offline` would prevent GitHub actions from failing jobs. But retaining `busy` or `idle` runners means that we need to keep runner pods running, which conflicts with our desired to scale to/from zero, hence we retain `offline` runners.
In this change, I enhanced the runnerreplicaset controller to create a registration-only runner on very beginning of its reconciliation logic, only when a runnerreplicaset is scaled to zero. The runner controller creates the registration-only runner pod, waits for it to become "offline", and then removes the runner pod. The runner on GitHub stays `offline`, until the runner resource on K8s is deleted. As we remove the registration-only runner pod as soon as it registers, this doesn't block cluster-autoscaler.
Related to #447
Yusuke Kuoka
Moto Ishizawa