{{- /* NetworkPolicy for searxng (Gitea #5). SearXNG is a metasearch engine, so like rss-bridge its egress can only be coarse: 443 to ANY destination, because querying search engines is the application and a NetworkPolicy cannot name a host. 6379 is allowed as well, for the EXTERNAL Valkey the limiter needs - this chart ships none of its own, and the URL lives in a 1Password item the chart never parses, so 6379 is the standard port rather than the configured one. What the cap buys here is the same narrow but real thing: no other outbound port, so a compromised instance cannot reach a database or a mail server. WHAT THIS OBJECT IS: a ceiling on reachability, not an authentication layer. Only the ports declared below are reachable at all - whatever else the process binds, now or after the next app update, is blocked without anyone having to notice it exists. WHAT IT IS NOT: - EGRESS IS COARSE. A NetworkPolicy matches CIDRs and selectors and NEVER hostnames, so "only to the database host" cannot be expressed at all. This cluster's CNI is Canal (Flannel plus Calico for policy) and has no FQDN rule; Calico's GlobalNetworkSet could express one but would bind this chart to Calico, the same argument that kept implementation-specific objects out of the Gateway-API sweep (#114). Each egress rule therefore permits its PORT to any destination. - NOT A BOUNDARY WHERE THE CNI DOES NOT ENFORCE ONE. An unenforced policy is accepted by the API server and filters nothing, so everything reads as configured while nothing is filtered. - THE REASONING IS IN TEMPLATE COMMENTS, not in "#" comments: those are part of the rendered object, travel into the cluster and appear in every release diff. ci/run-networkpolicy-test.sh fails on a rendered "#". THE PORT NUMBERS BELOW ARE POD PORTS, NEVER NODEPORTS. A NetworkPolicy is evaluated at the pod's network interface, after kube-proxy has already translated a NodePort to the targetPort, so a NodePort number here would match nothing while looking strict - and, being the only rule for that port, would block every inbound connection instead. ci/run-networkpolicy-test.sh asserts every port here against the containerPorts of the pod spec this policy selects. */ -}} {{- if .Values.networkPolicy.enabled }} {{- $np := .Values.networkPolicy }} {{- $ns := .Release.Namespace }} {{- $probeSources := $np.probeSources | default list }} {{- $allowedNs := $np.allowedNamespaces | default list }} {{- $ic := $np.ingressController | default dict }} {{- $routed := or .Values.ingress.enabled .Values.httpRoute.enabled }} {{- /* networkPolicy.ingress - the policy's INBOUND side, and not the same thing as networkPolicy.ingressController (the SOURCE SELECTOR for the ingress controller's pods, a SIBLING of it and no part of it) nor as the top-level .Values.ingress (the Ingress object). All three match a search for "ingress"; one round of this work already mistook the second for an inbound escape hatch on the strength of the substring. */}} {{- $npIngress := $np.ingress | default dict }} {{- $ambientMesh := $npIngress.ambientMesh }} apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: {{ .Release.Name }}-{{ .Chart.Name }}-networkpolicy labels: app: {{ .Release.Name }}-{{ .Chart.Name }}-networkpolicy spec: {{- /* Selects the Deployment's pods. ci/run-networkpolicy-test.sh fails if this matches no pod spec of the same render - which is the mistake that would otherwise leave a policy in the namespace filtering nothing, and its usual cause is a label renamed in the workload template. */}} podSelector: matchLabels: app: {{ .Release.Name }}-{{ .Chart.Name }}-deployment policyTypes: - Ingress {{- /* Egress is listed because there IS something to restrict: this workload needs DNS and the ports named below, and nothing else. A chart whose workload opens no outbound connection of its own must NOT list Egress - valkey is the example - because a rule that constrains nothing makes the object look stricter than it is. */}} - Egress ingress: {{- /* 8080 - the image's own GRANIAN_PORT and its EXPOSE, the port the Service targets, and the one all three probes address. The probe path. */}} - ports: - protocol: TCP port: 8080 {{- if $ambientMesh }} {{- /* FIRST HALF OF networkPolicy.ingress.ambientMesh (Gitea #143). 15008/TCP is ztunnel's HBONE tunnel, the port every inbound connection arrives on once the namespace carries istio.io/dataplane-mode - ambient "does not and will never bypass Kubernetes NetworkPolicy enforcement", so without it a pod in the mesh is simply unreachable. It is the one port here that is NOT a containerPort of the selected pod spec: ztunnel terminates it, not the application. ci/run-networkpolicy- test.sh therefore holds a NAMED exception for exactly this number, gated on exactly this value - and assertion 7 of that script proves, on a second render, that 15008 stays the ONLY such port and that it is absent while the value is false. NOT MEASURED: that 15008 alone suffices comes from Istio's documentation. Measured on this cluster is only which listeners ztunnel opens. Provable at the first namespace to join the mesh; none has. */}} - protocol: TCP port: 15008 {{- end }} {{- if $probeSources }} {{- /* RESTRICTED, because the operator supplied probeSources. The kubelet's probes come from the IP of the WORKER NODE running the pod, so that address has to be in the list or the pod never becomes Ready - and a pod that is never Ready reads as a broken application rather than as a policy. The ingress controller is added to the same rule, or the Ingress and the HTTPRoute both go dark the moment this list is filled. */}} from: - namespaceSelector: matchLabels: {{- /* Set by Kubernetes itself on every namespace (>= 1.21), so this needs no labelling work on a namespace this chart does not own. */}} kubernetes.io/metadata.name: {{ $ns }} {{- if and $routed $ic.namespace }} {{- /* ONE from-entry with TWO selectors, which is an AND: pods carrying these labels IN that namespace. Written as two list entries it would be an OR, and would open the port to every pod in kube-system. */}} - namespaceSelector: matchLabels: kubernetes.io/metadata.name: {{ $ic.namespace | quote }} {{- with $ic.podLabels }} podSelector: matchLabels: {{- toYaml . | nindent 14 }} {{- end }} {{- end }} {{- range $allowedNs }} - namespaceSelector: matchLabels: kubernetes.io/metadata.name: {{ . | quote }} {{- end }} {{- range $probeSources }} - ipBlock: cidr: {{ . | quote }} {{- end }} {{- if $ambientMesh }} {{- /* SECOND HALF OF networkPolicy.ingress.ambientMesh, and the reason it is one value and not two. Inside the mesh the kubelet's probes are redirected and no longer arrive from the worker node's address: they arrive from 169.254.7.127. An operator who only opens 15008 by hand writes a policy that passes review - and the moment probeSources is non-empty every probe is dropped, the pod never becomes Ready, and the symptom reads as a broken application rather than as a policy. That is assertion 4 of ci/run-networkpolicy-test.sh one value further along. A switch whose halves can only be had together cannot be set halfway. Only in this branch, because this is the only branch with a "from" list: with no sources restricted the rule is open and needs no peer. The IPv6 counterpart is deliberately absent - this cluster is SingleStack IPv4, and an ipBlock of the wrong family is accepted and matches nothing. UNPROVEN IN OPERATION: probeSources is empty in every chart here, so no release reaches this branch. CI proves its render, through the overlays in ci/networkpolicy. */}} - ipBlock: cidr: 169.254.7.127/32 {{- end }} {{- else }} {{- /* NO "from" SELECTOR, WHICH MEANS OPEN - deliberately, and only inside the cluster, because this port carries no NodePort. The alternative was to guess the worker node CIDRs, and a wrong guess blocks every kubelet probe: the pod stays un-Ready, the rollout times out, and the cause looks like the application. An empty "from: []" would be worse than either - it allows everything too, but while reading as a restriction. Narrow it with networkPolicy.probeSources. */}} {{- end }} egress: {{- /* DNS, unconditionally. There is no value to switch this off, and that is deliberate: a knob whose only other setting breaks every name lookup in the pod is a trap and not a feature. */}} - ports: - protocol: UDP port: 53 - protocol: TCP port: 53 {{- /* HTTPS to any destination. This IS the application: a metasearch engine that cannot reach the engines returns nothing. Cannot be narrowed - the engine list is hostnames, and this object matches CIDRs and selectors only. */}} - ports: - protocol: TCP port: 443 {{- /* Valkey/Redis for the limiter, on the STANDARD port. This chart deploys no Valkey; secrets.valkeySecretRef points at an external one through a URL the chart never parses, so a Valkey on another port needs networkPolicy.egress.extraPorts. */}} - ports: - protocol: TCP port: 6379 {{- with $np.egress }} {{- with .extraPorts }} {{- /* Ports only, to any destination - see the header. This is the operator's escape hatch from the egress cap, and the only alternative to switching the whole policy off. */}} - ports: {{- range . }} - protocol: TCP port: {{ int . }} {{- end }} {{- end }} {{- end }} {{- end }}