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home-network-k3s-impl/platform/cloudflared/networkpolicy.yaml
T
jakman85andClaude Opus 5.5 09f219fe7f
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fix(cloudflared): auditable Service+ServiceMonitor scrape; placeholder-only template value
servicemonitor-ports-resolve could not audit a PodMonitor with no in-repo
Service, and no-plaintext-secrets requires a template's secret value to be a
bare placeholder.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
2026-11-08 12:39:56 -06:00

150 lines
6.4 KiB
YAML

---
# Namespace baseline: deny everything both ways, except DNS to kube-system.
#
# SINGLE OWNER. This namespace is not labelled app-namespace=true, so Kyverno's
# require-default-deny-baseline generate rule does not select it and never writes this object;
# Flux is its only writer (the same posture as kured / crafty / headlamp / homepage). Do NOT add
# the app-namespace label to namespace.yaml without deleting this object in the same change, or
# the two controllers fight over it every reconcile (the 2026-09-30 drift-loop root cause).
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: default-deny
namespace: cloudflared
labels:
homelab.keithjackson.dev/baseline: default-deny
spec:
podSelector: {}
policyTypes:
- Ingress
- Egress
ingress: []
egress:
- to:
- namespaceSelector:
matchLabels:
kubernetes.io/metadata.name: kube-system
ports:
- protocol: UDP
port: 53
- protocol: TCP
port: 53
---
# The ONLY ingress: Prometheus scraping :2000. Shipped in the same file as the baseline on purpose
# (the Longhorn/kured lesson): a deny-all without this allow leaves the ServiceMonitor's targets
# DISCOVERED and every scrape timing out, which is the state the CloudflaredTunnelDown rule is
# written to fire on rather than go quiet in.
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: cloudflared-allow-prometheus-scrape
namespace: cloudflared
labels:
app.kubernetes.io/name: cloudflared
spec:
podSelector:
matchLabels:
app.kubernetes.io/name: cloudflared
policyTypes:
- Ingress
ingress:
- from:
- namespaceSelector:
matchLabels:
kubernetes.io/metadata.name: monitoring
ports:
- protocol: TCP
port: 2000
---
# Egress: the Cloudflare edge, the shared Gateway, and the Gateway's backends — nothing else.
#
# 1. world tcp+udp/7844 — the tunnel itself (QUIC on udp, HTTP/2 fallback on tcp).
# world tcp/443 — Cloudflare's API / update endpoints that cloudflared calls at start.
# Expressed as `world` + port rather than Cloudflare CIDRs: the edge ranges are Cloudflare's to
# change, and a stale CIDR list would fail as a silent outage. Narrowing to toCIDR is a
# possible later hardening; it is not done blind.
#
# 2. `ingress` entity tcp/443 — the shared Gateway's Envoy. Traffic to the
# cilium-gateway-shared Service is handed to Envoy, whose identity is reserved:ingress.
#
# 3. The Gateway's BACKENDS, by namespace. NOT optional: Cilium >= 1.16.8 (CVE-2025-30162; this
# cluster runs 1.20.x) makes the Gateway's Envoy re-evaluate THIS pod's egress policy against
# the identity of the backend it routes the request to. With only rule 2, Envoy accepts the TCP
# connection and then answers every request `403 Access denied` — measured for buildkit ->
# gitea on 2026-10-30, see platform/buildkit/networkpolicy.yaml. So the backends are named:
# * any namespace opted in to the shared Gateway (gateway-access=shared) — which is the set
# of namespaces that can serve a route at all, so this tracks new apps automatically;
# * MINUS the LAN/VPN-only services (operator decisions 2026-11-08): plex, jackett, pihole,
# semaphore, qbittorrent, radarr, sonarr, headlamp. config.yaml already 404s their
# hostnames; this is the second, independent layer: even a request that got past the
# ingress rules would be refused by Envoy for these backends.
# unifi and crafty-mc are not here because they are L4 LoadBalancer VIPs, not Gateway
# backends; the crafty WEB UI (crafty.<domain>, an HTTPRoute) is deliberately reachable.
#
# WHY NOT the `- {}` allow-all egress gitea-actions uses (apps/wave-1/gitea-actions.yaml)?
# It would satisfy the L7 re-check just as well, but `{}` admits EVERY identity, including
# kube-apiserver and host — which operator decision 4 (the Kubernetes API is never reachable
# through the tunnel) rules out for the one pod that carries internet traffic in. The
# namespace-label selector is the narrowest rule that still names every possible backend.
# Verified 2026-11-08: Cilium identities carry `k8s:io.cilium.k8s.namespace.labels.
# gateway-access`, and every namespace with an HTTPRoute on the shared Gateway is labelled
# gateway-access=shared.
#
# BACKENDS NEED NO INGRESS CHANGE. Envoy forwards to a backend as reserved:ingress, which every
# backend already admits; the source-identity check happens on THIS pod's egress, not on the
# destination's ingress. Measured 2026-10-30 (decisions/2026-10-30-gitea-admit-buildkit.md):
# gitea-actions is in none of Gitea's ingress allows and its requests through the Gateway reach
# Gitea, while Gitea's endpoint shows only a `reserved:ingress` allow row. So, unlike a
# ClusterIP client, cloudflared is not added to any app's inClusterClients. That also means
# this rule does not open a direct cloudflared -> app pod path into any app namespace whose
# ingress admits only reserved:ingress and named peers.
#
# DELIBERATELY ABSENT: kube-apiserver, host, remote-node, cluster, all. The Kubernetes API stays
# local-only (operator decision 2026-11-08); conformance/tests/l0-static/cloudflared-ingress-rules
# fails the gate if any of those entities appears here.
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: cloudflared-allow-egress
namespace: cloudflared
labels:
app.kubernetes.io/name: cloudflared
spec:
endpointSelector:
matchLabels:
app.kubernetes.io/name: cloudflared
egress:
- toEntities:
- world
toPorts:
- ports:
- port: "7844"
protocol: TCP
- port: "7844"
protocol: UDP
- port: "443"
protocol: TCP
- toEntities:
- ingress
toPorts:
- ports:
- port: "443"
protocol: TCP
- toEndpoints:
- matchExpressions:
- key: io.cilium.k8s.namespace.labels.gateway-access
operator: In
values:
- shared
- key: io.kubernetes.pod.namespace
operator: NotIn
values:
- plex
- jackett
- pihole
- semaphore
- qbittorrent
- radarr
- sonarr
- headlamp