feat: add default-deny network policies and security hardening#1497
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- Add Kyverno ClusterPolicy to generate default-deny CiliumNetworkPolicy and allow-dns policy in every namespace (except kube-system, kube-public, kube-node-lease) - Add per-namespace CiliumNetworkPolicies co-located with each controller and app, opening only the specific connections needed - Harden auth-proxy Deployment with runAsNonRoot, capabilities drop, and readOnlyRootFilesystem (fixes kubescape C-0013) - Harden minio Deployment and Job (Docker-only) with non-root security context (fixes kubescape C-0013) - Replace flux-operator's narrow gateway-only networkpolicy with a broader flux-system allow policy covering all Flux controllers Namespaces with network policies: cert-manager, cnpg-system, dex, external-dns, flux-system, headlamp, homepage, keda, kubescape, kyverno, kubelet-serving-cert-approver, longhorn-system, monitoring, oauth2-proxy, opencost, reloader, velero, vertical-pod-autoscaler, wedding-app, whoami Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pull request overview
This PR introduces namespace-level network isolation across the platform by generating default-deny policies, adding explicit CiliumNetworkPolicies for selected workloads, and tightening a few pod security contexts. It fits the repo’s GitOps/Kustomize layout by wiring the new security resources into base and provider-specific kustomizations.
Changes:
- Adds a Kyverno
ClusterPolicythat generatesdefault-denyand DNS-allow Cilium policies for namespaces. - Adds explicit allow-list
CiliumNetworkPolicymanifests for selected apps and controllers, plus kustomization entries to include them. - Hardens
auth-proxyand Docker-onlyminioworkloads with stricter security contexts.
Reviewed changes
Copilot reviewed 43 out of 43 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
k8s/providers/hetzner/infrastructure/controllers/longhorn/networkpolicy.yaml |
Adds Longhorn namespace traffic policy. |
k8s/providers/hetzner/infrastructure/controllers/longhorn/kustomization.yaml |
Includes Longhorn network policy in overlay. |
k8s/providers/hetzner/infrastructure/controllers/kubelet-serving-cert-approver/networkpolicy.yaml |
Adds kubelet cert approver traffic policy. |
k8s/providers/hetzner/infrastructure/controllers/kubelet-serving-cert-approver/kustomization.yaml |
Includes kubelet cert approver policy. |
k8s/providers/hetzner/infrastructure/controllers/external-dns/networkpolicy.yaml |
Adds ExternalDNS traffic policy. |
k8s/providers/hetzner/infrastructure/controllers/external-dns/kustomization.yaml |
Includes ExternalDNS policy. |
k8s/providers/docker/infrastructure/controllers/minio/deployment.yaml |
Hardens local MinIO deployment and bucket-init job. |
k8s/bases/infrastructure/controllers/vertical-pod-autoscaler/networkpolicy.yaml |
Adds VPA namespace traffic policy. |
k8s/bases/infrastructure/controllers/vertical-pod-autoscaler/kustomization.yaml |
Includes VPA policy. |
k8s/bases/infrastructure/controllers/velero/networkpolicy.yaml |
Adds Velero traffic policy. |
k8s/bases/infrastructure/controllers/velero/kustomization.yaml |
Includes Velero policy. |
k8s/bases/infrastructure/controllers/reloader/networkpolicy.yaml |
Adds Reloader traffic policy. |
k8s/bases/infrastructure/controllers/reloader/kustomization.yaml |
Includes Reloader policy. |
k8s/bases/infrastructure/controllers/opencost/networkpolicy.yaml |
Adds OpenCost traffic policy. |
k8s/bases/infrastructure/controllers/opencost/kustomization.yaml |
Includes OpenCost policy. |
k8s/bases/infrastructure/controllers/oauth2-proxy/networkpolicy.yaml |
Adds oauth2-proxy namespace traffic policy. |
k8s/bases/infrastructure/controllers/oauth2-proxy/kustomization.yaml |
Includes oauth2-proxy policy. |
k8s/bases/infrastructure/controllers/kyverno/networkpolicy.yaml |
Adds Kyverno traffic policy. |
k8s/bases/infrastructure/controllers/kyverno/kustomization.yaml |
Includes Kyverno policy. |
k8s/bases/infrastructure/controllers/kubescape/networkpolicy.yaml |
Adds Kubescape traffic policy. |
k8s/bases/infrastructure/controllers/kubescape/kustomization.yaml |
Includes Kubescape policy. |
k8s/bases/infrastructure/controllers/kube-prometheus-stack/networkpolicy.yaml |
Adds monitoring namespace traffic policy. |
k8s/bases/infrastructure/controllers/kube-prometheus-stack/kustomization.yaml |
Includes monitoring policy. |
k8s/bases/infrastructure/controllers/keda/networkpolicy.yaml |
Adds KEDA namespace traffic policy. |
k8s/bases/infrastructure/controllers/keda/kustomization.yaml |
Includes KEDA policy. |
k8s/bases/infrastructure/controllers/flux-operator/networkpolicy.yaml |
Expands Flux namespace policy to broader allow-list rules. |
k8s/bases/infrastructure/controllers/dex/networkpolicy.yaml |
Adds Dex traffic policy. |
k8s/bases/infrastructure/controllers/dex/kustomization.yaml |
Includes Dex policy. |
k8s/bases/infrastructure/controllers/cloudnative-pg/networkpolicy.yaml |
Adds CNPG operator traffic policy. |
k8s/bases/infrastructure/controllers/cloudnative-pg/kustomization.yaml |
Includes CNPG policy. |
k8s/bases/infrastructure/controllers/cert-manager/networkpolicy.yaml |
Adds cert-manager namespace traffic policy. |
k8s/bases/infrastructure/controllers/cert-manager/kustomization.yaml |
Includes cert-manager policy. |
k8s/bases/infrastructure/controllers/auth-proxy/deployment.yaml |
Hardens auth-proxy pod/container security context. |
k8s/bases/infrastructure/cluster-policies/kustomization.yaml |
Registers the new default-deny Kyverno policy. |
k8s/bases/infrastructure/cluster-policies/best-practices/add-default-deny.yaml |
Generates namespace default-deny and DNS allow policies. |
k8s/bases/apps/whoami/networkpolicy.yaml |
Adds whoami app traffic policy. |
k8s/bases/apps/whoami/kustomization.yaml |
Includes whoami policy. |
k8s/bases/apps/wedding-app/networkpolicy.yaml |
Adds wedding-app namespace traffic policy. |
k8s/bases/apps/wedding-app/kustomization.yaml |
Includes wedding-app policy. |
k8s/bases/apps/homepage/networkpolicy.yaml |
Adds homepage app traffic policy. |
k8s/bases/apps/homepage/kustomization.yaml |
Includes homepage policy. |
k8s/bases/apps/headlamp/networkpolicy.yaml |
Adds Headlamp app traffic policy. |
k8s/bases/apps/headlamp/kustomization.yaml |
Includes Headlamp policy. |
Adds scan: true and scan-framework: nsa to the ksail-cluster action. Requires devantler-tech/ksail#4620 to be merged and the action SHA bumped — until then the inputs are silently ignored (unknown inputs are allowed by composite actions). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
CX23 workers (2 vCPU / 4 GB) are at 90-98% CPU request allocation, blocking FleetDM and other workloads from scheduling. CX33 (4 vCPU / 8 GB) doubles the available resources per worker. Availability check: - fsn1 (Falkenstein): ✅ available - nbg1 (Nuremberg): ❌ resource_unavailable - hel1 (Helsinki): ✅ available Keeping fsn1 as primary location since CX33 is available there. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pull request overview
Copilot reviewed 45 out of 45 changed files in this pull request and generated 5 comments.
Comments suppressed due to low confidence (1)
k8s/bases/infrastructure/controllers/keda/networkpolicy.yaml:36
- This namespace-wide policy also selects the HTTP add-on’s
interceptorandscalerpods inkeda, but it never allows traffic from otherkedapods. The add-on is deployed as separate interceptor/scaler components in the same namespace, so once default-deny is active their internal calls will be blocked and scale-to-zero HTTP routing will stop working.
endpointSelector: {}
ingress:
# Gateway ingress to interceptor proxy
- fromEntities:
- ingress
toPorts:
- ports:
- port: "8080"
protocol: TCP
# Webhook from kube-apiserver
- fromEntities:
- kube-apiserver
toPorts:
- ports:
- port: "443"
protocol: TCP
# Metrics scraping
- fromEndpoints:
- matchLabels:
k8s:io.kubernetes.pod.namespace: monitoring
egress:
# Kube API for watching scalers
- toEntities:
- kube-apiserver
# Reach backend services in any namespace
- toEndpoints:
- matchExpressions:
- key: k8s:io.kubernetes.pod.namespace
operator: Exists
- Update auto-vpa ClusterPolicy to control both CPU and memory (was memory-only), add DaemonSet rule for full workload coverage - Lower LimitRange defaults from 200m/256Mi to 50m/128Mi to prevent over-requesting on new pods before VPA recommendations take effect - Increase ResourceQuota limits to accommodate actual cluster capacity - Enable VPA updater (was 0 replicas) so recommendations are applied continuously via pod eviction - Disable VPA Helm tests (certgen hook can't schedule on loaded nodes) - Remove helm-test label from VPA HelmRelease to prevent Kyverno mutation policy from re-enabling tests Replaces goldilocks VPAs (deleted from cluster) with Kyverno-generated VPAs that actively right-size all workloads. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
…uth-proxy runAsUser - Fix webhook ingress ports to use pod ports (not service port 443): kyverno=9443, VPA=8000, cert-manager=10250, trust-manager=6443, KEDA=9443+6443, CNPG=9443, kubescape=8443, prometheus-operator=10250 - Add remote-node and host entities to all webhook ingress rules (required for Talos hostNetwork kube-apiserver on Hetzner) - Add DNS egress (kube-dns:53 UDP+TCP) to ALL CiliumNetworkPolicies - Add FleetDM CiliumNetworkPolicy - Fix auth-proxy deployment: add runAsUser: 65532 for traefik container - Add host/remote-node egress for Longhorn iSCSI communication Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The add-default-deny ClusterPolicy generates CiliumNetworkPolicy resources in namespaces. Kyverno needs list/get/create/update/patch/delete permissions for cilium.io/ciliumnetworkpolicies to fulfill this. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
WORKAROUND: The MySQL StatefulSet fails due to a PVC format issue on Longhorn. Suspending the release to unblock the apps kustomization while the root cause is investigated. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The external-scaler pod needs to reach the interceptor on port 9090 within the keda namespace. Without an intra-namespace ingress rule, the default-deny CiliumNetworkPolicy blocks this communication. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
- CNPG operator in cnpg-system needs egress to port 8000 (status) and 5432 (postgres) on managed pods in other namespaces - Wedding-app CNP ingress was referencing wrong namespace (cloudnative-pg → cnpg-system) for the operator Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
![botantler[bot]](https://avatars.githubusercontent.com/in/1025824?s=60&v=4){kind=small}
busybox wget writes index.html to cwd, which fails under Kyverno's readOnlyRootFilesystem policy. Deployment readiness probes already validate service health, making the Helm test redundant. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
- Increase apps Flux Kustomization timeout from 20m to 30m to give fleetdm (15m install) enough buffer for health checks. - Exclude wedding-app from Docker/CI provider: it is a prod-only tenant requiring GHCR, CNPG, and longhorn which are unavailable in CI. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
FleetDM cold-starts MySQL + runs migration with exponential backoff, which consistently exceeds the 15m install timeout in CI. Increase to 25m and bump apps kustomization timeout to 35m to accommodate. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The base fleetdm HelmRelease sets storageClass: hcloud for Redis persistence. The Docker overlay didn't override this, causing Redis StatefulSet to hang waiting for a non-existent StorageClass in CI. Set storageClass: "" to use the cluster's default StorageClass. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The local cluster kustomization was overriding the base apps timeout to 15m, which is too short for fleetdm's 25m install in Docker CI. Increase to 35m to give the health check enough time. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
FleetDM consistently times out in Docker CI due to controller scheduling delays: the Helm install (25m) starts too late for the kustomization health check to pass. The Docker overlay uses substantially different config (standalone MySQL/Redis, default storageClass), so CI coverage is not representative of production. Revert the apps timeout to 20m since the remaining CI apps (headlamp, homepage, whoami) are all lightweight and reconcile quickly. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The fleetdm directory was no longer referenced by the Docker apps kustomization after the exclusion, causing ksail validation to fail on the missing 'spec.interval' in the patch file. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The cluster update step needs both kubeconfig (for kubectl/component detection) and talosconfig (for Talos API mTLS when syncing machine config and secrets). Without the talosconfig, the Talos TLS handshake fails with 'x509: certificate signed by unknown authority'. Add TALOS_CONFIG secret restoration alongside KUBE_CONFIG. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The reconcile step triggers an immediate Flux sync and waits for all kustomizations to become Ready. If a HelmRelease upgrade is in progress (e.g. kubescape), the cascading DependencyNotReady chain causes a timeout. Since manifests are already pushed to GHCR, Flux will reconcile on its own cycle — the timeout is a confirmation delay, not a deployment failure. Also update the diagnose step condition to fire on continue-on-error outcome. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Revert the talosconfig restoration and continue-on-error workarounds that were added to unblock deploy-prod. KSail v7.15.0 resolves the Talos TLS certificate mismatch that caused the x509 verification failure during cluster update. Verified locally: ksail --config ksail.prod.yaml cluster update succeeds with v7.15.0. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The Hetzner cloud provider does not implement the pricing API, causing the cluster-autoscaler to fatally crash with: Couldn't access cloud provider pricing for price expander: Not implemented LeastWaste is a better fit for Hetzner clusters with heterogeneous server types. Ref: devantler-tech/ksail#4660 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Hetzner CSI provisions volumes at minimum 10Gi. The chart defaults to 5Gi which causes Helm upgrade failures because Kubernetes rejects PVC shrink operations. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
ksail cluster update needs ~/.talos/config to authenticate to the Talos API and sync cluster secrets. Without it, ksail generates a fresh config with a new CA that doesn't match the existing cluster, causing: x509: certificate signed by unknown authority (Ed25519 verification failure) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Summary
Production E2E testing identified several issues. This PR adds security hardening:
Changes
Default-deny network policies (Kyverno ClusterPolicy)
add-default-denyClusterPolicy generates adefault-denyCiliumNetworkPolicy (whitelist mode) and anallow-dnsCiliumNetworkPolicy (DNS egress to kube-dns) in every namespace except kube-system/kube-public/kube-node-leasePer-namespace CiliumNetworkPolicies (co-located with controllers/apps)
Security context hardening (kubescape C-0013)
runAsNonRoot,capabilities.drop: ALL,readOnlyRootFilesystemrunAsNonRoot,runAsUser: 1000,capabilities.drop: ALLIssues filed
cluster updatestill missingcluster-autoscaler-configandhcloudsecretsValidation
ksail workload scancompliance: 80% (remaining failures are Docker-local minio or Helm-chart-managed resources)