{{- /* NetworkPolicy for apache-tika (Gitea #5). Apache Tika here is a cluster-internal service: the chart creates no Ingress at all, and its only consumers are other pods - paperless-ngx points at http://..svc.cluster.local for text extraction. THAT MAKES THE SOURCE QUESTION THE INTERESTING ONE, AND IT HAS AN AWKWARD ANSWER. 9998 is the port all three probes address, so it cannot be restricted by source without the worker node's IP - and this chart's consumers live in OTHER namespaces (paperless-cmk, paperless-jk, paperless-tb in this cluster). So an operator who narrows probeSources has to list those namespaces in allowedNamespaces in the same breath, or every document extraction stops. That is written into values.yaml and NOTES.txt rather than left to be discovered. Egress is DNS only. Tika extracts text from documents it is handed; it fetches nothing, and a text extractor that can reach the internet is a worse thing to hand an untrusted document to. 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 }} 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 real to restrict: Tika extracts text from documents it is handed and fetches nothing of its own, so DNS is the only rule. A text extractor that can reach the internet is a worse thing to hand an untrusted document to. */}} - Egress ingress: {{- /* 9998 - the only port this pod declares, the one the Service forwards 80 to, and the one all three probes address. The probe path. */}} - ports: - protocol: TCP port: 9998 {{- 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. NO ingress controller is added here, because this chart renders no Ingress: its consumers are other pods, and they have to be named in allowedNamespaces. */}} 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 }} {{- range $allowedNs }} - namespaceSelector: matchLabels: kubernetes.io/metadata.name: {{ . | quote }} {{- end }} {{- range $probeSources }} - ipBlock: cidr: {{ . | quote }} {{- 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 {{- 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 }}