Enhances #57 to add support for organizational runners.
As GitHub Actions does not have an appropriate API for this, this is the spec you need:
```
apiVersion: actions.summerwind.dev/v1alpha1
kind: RunnerDeployment
metadata:
name: myrunners
spec:
minReplicas: 1
maxReplicas: 3
autoscaling:
metrics:
- type: TotalNumberOfQueuedAndProgressingWorkflowRuns
repositories:
# Assumes that you have `github.com/myorg/myrepo1` repo
- myrepo1
- myrepo2
template:
spec:
organization: myorg
```
It works by collecting "in_progress" and "queued" workflow runs for the repositories `myrepo1` and `myrepo2` to autoscale the number of replicas, assuming you have this organizational runner deployment only for those two repositories.
For example, if `myrepo1` had 1 `in_progress` and 2 `queued` workflow runs, and `myrepo2` had 4 `in_progress` and 8 `queued` workflow runs at the time of running the reconcilation loop on the runner deployment, it will scale replicas to 1 + 2 + 4 + 8 = 15.
Perhaps we might be better add a kind of "ratio" setting so that you can configure the controller to create e.g. 2x runners than demanded. But that's another story.
Ref #10
* feat: Repository-wide RunnerDeployment Autoscaling
This adds `maxReplicas` and `minReplicas` to the RunnerDeploymentSpec. If and only if both fields are set, the controller computes and sets desired `replicas` automatically depending on the demand.
The number of demanded runner replicas is computed by `queued workflow runs + in_progress workflow runs` for the repository. The support for organizational runners is not included.
Ref https://github.com/summerwind/actions-runner-controller/issues/10
Since the initial implementation of RunnerDeployment and until this change, any update to a runner deployment has been leaving old runner replicasets until the next resync interval. This fixes that, by continusouly retrying the reconcilation 10 seconds later to see if there are any old runner replicasets that can be removed.
In addition to that, the cleanup of old runner replicasets has been improved to be deferred until all the runners of the newest replica set to be available. This gives you hopefully zero or at less downtime updates of runner deployments.
Fixes#24
