--- # Gitea Actions runner (act_runner) — Phase 6 CI/CD (WS-GITOSS). # # WHY A DEDICATED, NON-APP NAMESPACE: # The runner's job executor is a Docker-in-Docker (DinD) sidecar that MUST run # `privileged: true` (dockerd needs it). The Kyverno `restrict-host-namespaces` # policy denies privileged containers, but it (and the egress-class / auth-mode / # default-deny-baseline policies) scope ONLY to namespaces labeled # homelab.keithjackson.dev/app-namespace: "true". This namespace deliberately does # NOT carry that label — it is CI plumbing, not a user-facing app — so the privileged # DinD sidecar is admitted WITHOUT a policy exception. (Verified: a privileged Pod in # a non-app namespace passes server-side admission; Kyverno test fixture # `platform-workload` is likewise Excluded from restrict-host-namespaces.) # # EXECUTOR MODEL — Docker executor + DinD sidecar (privileged): # act_runner runs each job step inside a container it launches via a Docker daemon. # That daemon is the co-located `dind` sidecar (shared pod netns → tcp://localhost:2376, # TLS via a shared emptyDir of certs). Tradeoff vs the host/self-hosted executor: DinD # needs `privileged`, but it gives clean per-job isolation and lets the workflow pick its # own job image (the pinned toolchain), which the host executor cannot. Privileged is # contained to this CI-only namespace and the runner mounts NO ServiceAccount token # (automountServiceAccountToken: false) — CI holds no cluster credentials (R-SEC-02). apiVersion: v1 kind: Namespace metadata: name: gitea-actions labels: # NOTE: intentionally NO homelab.keithjackson.dev/app-namespace label (see header). homelab.keithjackson.dev/ci: act-runner --- # Default-deny ingress; broad egress (a CI runner legitimately needs the internet: # ghcr.io / github.com / docker hub / dl.k8s.io / pypi for job images + pinned tools, # and the Gitea ingress VIP for registration + repo clone). Nothing connects INTO the # runner, so ingress is denied entirely. apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: default-deny-ingress-allow-egress namespace: gitea-actions labels: homelab.keithjackson.dev/baseline: default-deny spec: podSelector: {} policyTypes: - Ingress - Egress ingress: [] egress: # DNS (cluster + split-horizon resolution of gitea.home.keithjackson.dev). - to: - namespaceSelector: matchLabels: kubernetes.io/metadata.name: kube-system ports: - protocol: UDP port: 53 - protocol: TCP port: 53 # Everything else the runner + DinD need: Gitea VIP + internet registries/tool hosts. - {} --- # Runner state (config.yaml + the `.runner` registration file) persists here so the # runner registers exactly ONCE and reuses its identity across restarts (no duplicate # offline rows in Gitea). RWO → Deployment strategy must be Recreate (fix/recreate-strategy-rwo). apiVersion: v1 kind: PersistentVolumeClaim metadata: name: act-runner-data namespace: gitea-actions labels: app.kubernetes.io/name: act-runner spec: accessModes: - ReadWriteOnce storageClassName: longhorn resources: requests: storage: 1Gi --- apiVersion: apps/v1 kind: Deployment metadata: name: act-runner namespace: gitea-actions labels: app.kubernetes.io/name: act-runner spec: replicas: 1 strategy: type: Recreate selector: matchLabels: app.kubernetes.io/name: act-runner template: metadata: labels: app.kubernetes.io/name: act-runner spec: # CI holds no cluster credentials — do not mount a SA token into the runner or # (via the shared netns) the job containers (R-SEC-02, docs/14). automountServiceAccountToken: false # ---- Docker-in-Docker: the job executor daemon (privileged) ------------------- # # NATIVE SIDECAR (k3s v1.36; sidecar containers are GA). It is an initContainer with # `restartPolicy: Always`, which means: it starts BEFORE the regular containers, keeps # running alongside them, and is terminated after them. kubelet holds `runner` until # this container's startupProbe passes, so the ordering is enforced by the kubelet # instead of hand-rolled shell in the runner. # # This REPLACES two bounded wait-loops that used to live in the runner's `command:`. # Deleting them also deletes an envsubst hazard: clusters/base/apps-wave-1.yaml runs # postBuild substitution over this ENTIRE manifest, comments included, and those loops # depended on bare dollar-names surviving it untouched. There is now no shell here at # all, so there is nothing to escape or mis-escape. # # WHY THE PROBE IS `exec docker ... info` AND NOT `tcpSocket`. A tcpSocket probe would # re-open the exact gap the old Stage 1 existed to close: dockerd writes the TLS certs # and only THEN begins listening, so the port can accept a connection while the certs # are absent or incomplete -- and act_runner hard-exits on a missing # /certs/client/ca.pem. A full TLS-verified `docker info` proves BOTH that the certs # are usable and that the daemon answers. It also removes the one-per-start # "TLS handshake error ... EOF" that the old `nc -z` probe logged in dockerd. # # periodSeconds 1 x failureThreshold 60 preserves the previous 60s cap. initContainers: - name: dind restartPolicy: Always # <- this field is what makes it a SIDECAR image: docker:27-dind securityContext: privileged: true env: # Generate + publish TLS certs into the shared emptyDir; dockerd then listens # on tcp://0.0.0.0:2376 (TLS) which the runner reaches at localhost:2376. - name: DOCKER_TLS_CERTDIR value: /certs volumeMounts: - name: certs mountPath: /certs - name: dind-storage mountPath: /var/lib/docker resources: requests: cpu: 100m memory: 256Mi limits: memory: 2Gi startupProbe: exec: command: - docker - --host=tcp://127.0.0.1:2376 - --tlsverify - --tlscacert=/certs/client/ca.pem - --tlscert=/certs/client/cert.pem - --tlskey=/certs/client/key.pem - info periodSeconds: 1 failureThreshold: 60 containers: # ---- act_runner: registers with Gitea, dispatches jobs to the DinD daemon ---- - name: runner image: gitea/act_runner:0.2.11 # No `command:` override. The image's own entrypoint (/sbin/tini -- /opt/act/run.sh) # registers from env on first boot and runs `act_runner daemon`. The two wait-loops # that used to live here are gone: kubelet now holds this container until the dind # sidecar's startupProbe passes (see initContainers above). env: - name: GITEA_INSTANCE_URL value: https://gitea.${BASE_DOMAIN} - name: GITEA_RUNNER_REGISTRATION_TOKEN valueFrom: secretKeyRef: name: gitea-actions-runner key: token - name: GITEA_RUNNER_NAME value: incluster-dind # runs-on label -> job image. Both map to the catthehacker "act" image, which # carries bash/git/curl/tar/python3+pip/node so .gitea/workflows scripts can # install the pinned CI toolchain (ci/versions.env) and actions/checkout runs. - name: GITEA_RUNNER_LABELS value: "ubuntu-latest:docker://ghcr.io/catthehacker/ubuntu:act-22.04,homelab:docker://ghcr.io/catthehacker/ubuntu:act-22.04" # Reach the DinD daemon over the shared pod network namespace, TLS-verified # against the certs the sidecar drops into the shared /certs emptyDir. - name: DOCKER_HOST value: tcp://localhost:2376 - name: DOCKER_CERT_PATH value: /certs/client - name: DOCKER_TLS_VERIFY value: "1" volumeMounts: - name: data mountPath: /data - name: certs mountPath: /certs readOnly: true resources: requests: cpu: 100m memory: 128Mi limits: memory: 512Mi volumes: - name: data persistentVolumeClaim: claimName: act-runner-data - name: certs emptyDir: {} - name: dind-storage emptyDir: {}