{{- /* NetworkPolicy for teamspeak-server (Gitea #5). Three ports, two of them NodePorts facing the internet and one that is purely internal - so this chart shows the public/internal split without the probe problem getting in the way of either. voice (UDP) NodePort, open. The clients are on the internet. fileTransfer (TCP) NodePort, open, and also the port all three probes open a socket against - justified twice. web query (10080) NO Service at all, no probe, so it is RESTRICTED to this namespace plus allowedNamespaces. That is the rule worth having here: the query interface is administrative. NOTE THE PORT NUMBERS. This chart happens to use the SAME number for the pod port and the NodePort (server.voicePort, server.fileTransferPort are both), so the usual NodePort mistake is invisible here - the number is right either way. That is a coincidence of this chart's values and not a rule; do not copy the pattern to a chart where the two differ. 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 }} {{- $allowedNs := $np.allowedNamespaces | default list }} {{- /* networkPolicy.ingress - the policy's INBOUND side, and not the same thing as the top-level .Values.ingress (the Ingress object) - both match a search for "ingress". */}} {{- $npIngress := $np.ingress | default dict }} {{- /* NULL-SAFE ON PURPOSE (#99): ambientMesh is an OBJECT, so every read goes through a fallback reproducing THIS chart's declared defaults. An operator who deletes the object, or writes only "enabled: true", must land on the defaults and not in a nil dereference - #136 shipped exactly that defect one value away, where the NOTES.txt branch dereferenced .networkPolicy.egress directly. */}} {{- $ambient := $npIngress.ambientMesh | default dict }} {{- $ambientEnabled := $ambient.enabled }} {{- $ambientPort := $ambient.port | default 15008 }} apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: {{ .Release.Name }}-{{ .Chart.Name }}-networkpolicy labels: app: {{ .Release.Name }}-{{ .Chart.Name }}-networkpolicy spec: {{- /* Selects the StatefulSet'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 }}-sfs policyTypes: - Ingress {{- /* Egress is listed because a voice server's outbound needs are small: DNS and HTTPS. The uncertainty is named in the rule itself rather than hidden - see the note on TeamSpeak's accounting ports. */}} - Egress ingress: {{- /* THE VOICE PORT, UDP, published as a NodePort and deliberately open: the clients are on the internet, and after masquerading the source address is a cluster node anyway. PROTOCOL MATTERS AS MUCH AS THE NUMBER HERE. Voice is UDP, and a rule written for TCP on the same number would be accepted, would look complete, and would drop every voice packet - which is why ci/run-networkpolicy-test.sh checks the protocol against the containerPort's and not just the number. */}} - ports: - protocol: UDP port: {{ .Values.server.voicePort | int64 }} {{- /* THE FILE-TRANSFER PORT, TCP, also a NodePort and also open. It is additionally the port all three probes open a TCP socket against, so it is the probe path as well - open for two independent reasons. */}} - ports: - protocol: TCP port: {{ .Values.server.fileTransferPort | int64 }} {{- if $ambientEnabled }} {{- /* 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 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 holds a NAMED exception for exactly this number, gated on exactly this value, and proves on a second render that it stays the only such port and that it is absent while the value is false. THE PORT HALF ONLY, and that is not an omission. Elsewhere this switch also adds 169.254.7.127/32 as a probe source, because inside the mesh the kubelet's probes are redirected away from the worker node's address. This chart offers no networkPolicy.probeSources at all, so the rule carrying the probe port is never restricted by source - and an unrestricted rule needs no probe address. Measured in the render: three tcpSocket probes, so these ARE network probes - they are simply never restricted here. WHICH RULE IT JOINS: the file-transfer rule, the policy's open TCP rule. The voice rule is UDP and the rule on 10080 is restricted to the namespace. A policy is an OR over its rules, so which rule carries the port decides only which sources reach it - and an open TCP rule is the honest default while it is unknown where ztunnel dials from. AN ISTIO CONSTANT, NOT A STANDARD: 15008 is not registered with IANA for this, no protocol prescribes it, and Kubernetes knows nothing about it - Istio picked it for HBONE and Istio can change it. Hence a VALUE with a documented default rather than a literal here, so an operator can correct it without a chart release. Read for ztunnel 1.30.6. The exception ci/run-networkpolicy-test.sh grants is pinned to the number THAT TEST names, plus a check that this chart declares the same default - never to whatever the value says, because that would let a mistyped port ride in through a configurable field (design A of #143). 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: {{ int $ambientPort }} {{- end }} {{- /* THE WEB QUERY INTERFACE, and the one rule in this chart with real security value. It has no Service and no probe, so it can be restricted, and it is: this namespace plus allowedNamespaces. The query interface is administrative, and before this object the only thing keeping it off the network was that nothing published it. */}} - ports: - protocol: TCP port: 10080 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 }} 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 {{- /* Outbound HTTPS, for the server's own update and accounting calls. To any destination - hostnames cannot appear here. IF THE SERVER REFUSES TO START AFTER THIS POLICY ARRIVES, THIS IS THE RULE TO WIDEN: TeamSpeak's accounting service has historically used ports of its own (TCP 2008, UDP 2010 on the 3.x line), and this chart cannot know what the 6.x beta does. The install-test covers this chart, so a startup that depends on a blocked port shows up there rather than in production - but a license or accounting check that merely degrades would not. */}} - ports: - protocol: TCP port: 443 {{- 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 }}