CronJob to clean up PipelineRuns, keeping up to `NUM_TO_KEEP` of runs of each pipeline

tekton-pipelinerun-cleaner.yaml

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: tekton-pipelinerun-cleaner
  labels:
    app: tekton-pipelinerun-cleaner
    app.kubernetes.io/name: tekton-pipelinerun-cleaner
    app.kubernetes.io/component: pipelinerun-cleaner
    app.kubernetes.io/part-of: tekton
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: tekton-pipelinerun-cleaner
  labels:
    app: tekton-pipelinerun-cleaner
    app.kubernetes.io/name: tekton-pipelinerun-cleaner
    app.kubernetes.io/component: pipelinerun-cleaner
    app.kubernetes.io/part-of: tekton
rules:
  - apiGroups:
      - tekton.dev
    resources:
      - pipelineruns
    verbs:
      - delete
      - get
      - watch
      - list
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: tekton-pipelinerun-cleaner
  labels:
    app: tekton-pipelinerun-cleaner
    app.kubernetes.io/name: tekton-pipelinerun-cleaner
    app.kubernetes.io/component: pipelinerun-cleaner
    app.kubernetes.io/part-of: tekton
roleRef:
  kind: Role
  name: tekton-pipelinerun-cleaner
  apiGroup: rbac.authorization.k8s.io
subjects:
  - kind: ServiceAccount
    name: tekton-pipelinerun-cleaner
---
apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: tekton-pipelinerun-cleaner
  labels:
    app: tekton-pipelinerun-cleaner
    app.kubernetes.io/name: tekton-pipelinerun-cleaner
    app.kubernetes.io/component: pipelinerun-cleaner
    app.kubernetes.io/part-of: tekton
spec:
  schedule: "*/15 * * * *"
  concurrencyPolicy: Forbid
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          serviceAccount: tekton-pipelinerun-cleaner
          containers:
            - name: kubectl
              image: docker.io/alpine/k8s:1.20.7
              env:
                - name: NUM_TO_KEEP
                  value: "3"
              command:
                - /bin/bash
                - -c
                - >
                  while read -r PIPELINE; do
                    while read -r PIPELINE_TO_REMOVE; do
                      test -n "${PIPELINE_TO_REMOVE}" || continue;
                      kubectl delete ${PIPELINE_TO_REMOVE} \
                          && echo "$(date -Is) PipelineRun ${PIPELINE_TO_REMOVE} deleted." \
                          || echo "$(date -Is) Unable to delete PipelineRun ${PIPELINE_TO_REMOVE}.";
                    done < <(kubectl get pipelinerun -l tekton.dev/pipeline=${PIPELINE} --sort-by=.metadata.creationTimestamp -o name | head -n -${NUM_TO_KEEP});
                  done < <(kubectl get pipelinerun -o go-template='{{range .items}}{{index .metadata.labels "tekton.dev/pipeline"}}{{"\n"}}{{end}}' | uniq);
              resources:
                requests:
                  cpu: 50m
                  memory: 32Mi
                limits:
                  cpu: 100m
                  memory: 64Mi

could this be migrated to a git repo?
if not I can live with this here

@georgettica copied to https://github.com/3scale-ops/tekton-pipelinerun-cleaner