blumeops/compensating-controls.yaml

# Compensating Controls
#
# Documents controls that mitigate risks from suppressed or accepted security
# findings. Referenced by security tools (Prowler mutelist, Kingfisher config,
# etc.) via "CC: <id>" in finding descriptions or suppression notes.
#
# Used by `mise run review-compensating-controls` to surface stale controls.
#
# Fields:
#   id              - kebab-case unique identifier, referenced from tool configs
#   description     - what the control actually does to mitigate risk
#   created         - date (YYYY-MM-DD) the control was documented
#   last-reviewed   - date (YYYY-MM-DD) or null
#   notes           - optional context

controls:
  - id: single-user-cluster
    description: >-
      Only the cluster operator (eblume) has kubectl access. No untrusted
      users can create pods, access cached images, or bind RBAC roles.
    created: 2026-03-30
    last-reviewed: 2026-04-01
    notes: >-
      Verify by checking kubeconfig distribution and Tailscale ACLs.
      If additional users gain cluster access, re-evaluate all findings
      muted under this control.

  - id: tailscale-network-isolation
    description: >-
      Cluster is not internet-exposed. All access requires Tailscale
      identity with ACL enforcement. Profiling endpoints, debug ports,
      and control-plane APIs are unreachable from the public internet.
    created: 2026-03-30
    last-reviewed: 2026-04-06
    notes: >-
      Verify with 'tailscale serve status --json' on indri and review
      Tailscale ACLs in pulumi/tailscale/. Only tag:flyio-target services
      are publicly routable.

  - id: local-registry
    description: >-
      Operator-built services use a private zot registry
      (registry.ops.eblu.me) for supply-chain control. Remaining
      images are pulled from public registries without stored
      credentials. No shared registry secrets are cached on cluster
      nodes.
    created: 2026-03-30
    last-reviewed: 2026-04-12
    notes: >-
      Verify by checking image prefixes in kustomization.yaml files.
      Known external-image categories: (1) upstream apps not yet
      mirrored — immich, ollama, frigate, frigate-notify, valkey;
      (2) infrastructure components — tailscale operator/proxy,
      external-secrets, 1password-connect, forgejo-runner, docker
      DinD, nvidia-device-plugin; (3) utility base images — busybox,
      alpine (grafana init containers). Track upstream versions in
      service-versions.yaml. Goal is to progressively mirror these
      into zot.

  - id: sso-gated-admin-tools
    description: >-
      ArgoCD and Grafana require SSO authentication via Authentik OIDC.
      Wildcard RBAC in ArgoCD is mitigated by requiring authenticated
      identity before any API access.
    created: 2026-03-30
    last-reviewed: 2026-03-30
    notes: >-
      Verify Authentik provider config and that anonymous access is
      disabled. Check ArgoCD --auth-token isn't leaked.

  - id: operator-managed-pods
    description: >-
      Tailscale operator manages proxy pod specs (ts-*, ingress-*,
      operator-*, nameserver-*). Pod security settings are set by the
      operator, not user manifests. Operator is tracked in
      service-versions.yaml and regularly updated.
    created: 2026-03-30
    last-reviewed: 2026-03-30
    notes: >-
      Verify operator version is current via 'mise run service-review'.
      Check Tailscale changelog for security fixes. If operator adds
      seccomp support, remove these mutes.

  - id: ephemeral-privileged-jobs
    description: >-
      Prowler CIS scanner runs as a CronJob with 7-day TTL
      auto-deletion, not as a persistent privileged workload. hostPID
      exposure is time-bounded to scan duration (~20s).
    created: 2026-03-30
    last-reviewed: 2026-03-30
    notes: >-
      Verify TTL is set in cronjob.yaml. Check that no persistent
      pods run with hostPID.

  - id: trusted-ci-only
    description: >-
      Forgejo runner only executes workflows from repos on the private
      forge (forge.ops.eblu.me). No external or untrusted repos can
      trigger privileged CI jobs.
    created: 2026-03-30
    last-reviewed: 2026-03-30
    notes: >-
      Verify runner registration is limited to the forge instance.
      Check Forgejo runner config for repo allow-lists.

  - id: init-container-isolation
    description: >-
      Root privileges and added capabilities (CHOWN) are limited to
      init containers that run once at pod startup. All runtime
      containers run as non-root (UID 472) with all capabilities
      dropped.
    created: 2026-03-30
    last-reviewed: 2026-03-30
    notes: >-
      Verify by inspecting grafana deployment.yaml securityContext
      for both init and runtime containers. If fsGroup alone can
      handle PVC ownership, remove init-chown-data and this control.

  - id: node-config-automated-verification
    description: >-
      Prowler reports certain node-level checks as MANUAL because it runs
      inside a pod and cannot evaluate kubelet file permissions, kubelet
      config arguments, etcd CA separation, or cluster-admin RBAC bindings.
      The review-compliance-reports script SSHes into the minikube node
      weekly and programmatically verifies each condition, failing loudly
      if any check deviates from expected values.
    created: 2026-04-14
    last-reviewed: 2026-04-14
    notes: >-
      Verification runs as part of 'mise run review-compliance-reports'.
      If minikube node is unreachable, all checks report as FAIL. If new
      MANUAL findings appear in Prowler, add corresponding verification
      logic to the script and update the mutelist.

  - id: observability-stack-audit
    description: >-
      Alloy collects pod logs and ships them to Loki, providing an
      audit trail for cluster activity. Compensates for missing
      apiserver audit logging which minikube does not configure.
    created: 2026-03-30
    last-reviewed: 2026-03-30
    notes: >-
      Verify Alloy DaemonSet is running and Loki is receiving logs.
      Note this is weaker than native apiserver audit logs — it
      captures pod stdout/stderr, not API request-level auditing.
      Consider enabling minikube audit logging if supported.