feat(networkPolicies): template custom network policies

README.md

@@ -148,6 +148,61 @@ helm install prometheus-fail2ban-exporter prometheus-exporters/prometheus-fail2b
   --set 'grafana.enabled=true'
 ```
 
+### Network policies
+
+Network policies can only take effect, when the used CNI plugin support network policies. The chart supports no custom
+network policy implementation of CNI plugins. It's support only the official API resource of `networking.k8s.io/v1`.
+
+The object networkPolicies can contains multiple networkPolicy definitions. There is currently only one example
+predefined - it's named `default`. Further networkPolicy rules can easy be added by defining additional objects. For example:
+
+> [!NOTE]
+> The structure of each custom network policy must be equal like that of default. For this reason don't forget to define
+> `annotations`, `labels` and the other properties as well.
+
+```yaml
+networkPolicies:
+  enabled: false
+  default: {}
+  my-custom-network-policy: {}
+```
+
+The example below is an excerpt of the `values.yaml` file. The network policy `default` contains ingress rules to allow
+incoming traffic from Prometheus.
+
+> [!IMPORTANT]
+> Please keep in mind, that the namespace and pod selector labels can be different from environment to environment. For
+> this reason, there is are not default network policy rules defined.
+
+```yaml
+networkPolicies:
+  enabled: true
+  default:
+    enabled: true
+    annotations: {}
+    labels: {}
+    policyTypes:
+    - Egress
+    - Ingress
+    egress: []
+      ports:
+      - port: 53
+        protocol: TCP
+      - port: 53
+        protocol: UDP
+    ingress:
+    - from:
+      - namespaceSelector:
+          matchLabels:
+            kubernetes.io/metadata.name: monitoring
+        podSelector:
+          matchLabels:
+            app.kubernetes.io/name: prometheus
+      ports:
+      - port: http
+        protocol: TCP
+```
+
 ## Parameters
 
 ### Global

templates/prometheus-fail2ban-exporter/_networkPolicies.tpl

@@ -0,0 +1,19 @@
+{{/* vim: set filetype=mustache: */}}
+
+{{/* annotations */}}
+
+{{- define "prometheus-fail2ban-exporter.networkPolicies.annotations" -}}
+{{ include "prometheus-fail2ban-exporter.annotations" .context }}
+{{- if .networkPolicy.annotations }}
+{{ toYaml .networkPolicy.annotations }}
+{{- end }}
+{{- end }}
+
+{{/* labels */}}
+
+{{- define "prometheus-fail2ban-exporter.networkPolicies.labels" -}}
+{{ include "prometheus-fail2ban-exporter.labels" .context }}
+{{- if .networkPolicy.labels }}
+{{ toYaml .networkPolicy.labels }}
+{{- end }}
+{{- end }}

templates/prometheus-fail2ban-exporter/networkPolicies.yaml

@@ -0,0 +1,36 @@
+{{- if .Values.networkPolicies.enabled }}
+{{- range $key, $value := .Values.networkPolicies -}}
+{{- if and (not (eq $key "enabled")) $value.enabled }}
+---
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  {{- with (include "prometheus-fail2ban-exporter.networkPolicies.annotations" (dict "networkPolicy" $value "context" $) | fromYaml) }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+  {{- with (include "prometheus-fail2ban-exporter.networkPolicies.labels" (dict "networkPolicy" $value "context" $) | fromYaml) }}
+  labels:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+  name: {{ printf "%s-%s" (include "prometheus-fail2ban-exporter.fullname" $ ) $key }}
+  namespace: {{ $.Release.Namespace }}
+spec:
+  podSelector:
+    matchLabels:
+      {{- include "prometheus-fail2ban-exporter.pod.selectorLabels" $ | nindent 6 }}
+  {{- with $value.policyTypes }}
+  policyTypes:
+  {{- toYaml . | nindent 2 }}
+  {{- end }}
+  {{- with $value.egress }}
+  egress:
+  {{- toYaml . | nindent 2 }}
+  {{- end }}
+  {{- with $value.ingress }}
+  ingress:
+  {{- toYaml . | nindent 2 }}
+  {{- end }}
+{{- end }}
+{{- end }}
+{{- end }}

unittests/networkPolicies/default.yaml

@@ -0,0 +1,118 @@
+chart:
+  appVersion: 0.1.0
+  version: 0.1.0
+suite: NetworkPolicies template (basic)
+release:
+  name: prometheus-fail2ban-exporter-unittest
+  namespace: testing
+templates:
+- templates/prometheus-fail2ban-exporter/networkPolicies.yaml
+tests:
+- it: Skip networkPolicies in general disabled.
+  set:
+    networkPolicies.enabled: false
+  asserts:
+  - hasDocuments:
+      count: 0
+
+- it: Skip networkPolicy 'default' when disabled.
+  set:
+    networkPolicies.enabled: true
+    networkPolicies.default.enabled: false
+  asserts:
+  - hasDocuments:
+      count: 0
+
+- it: Loop over networkPolicies
+  set:
+    networkPolicies.enabled: true
+    networkPolicies.default.enabled: false
+    networkPolicies.nginx.enabled: true
+    networkPolicies.prometheus.enabled: true
+  asserts:
+  - hasDocuments:
+      count: 2
+
+- it: Template networkPolicy 'default' without policyTypes, egress and ingress configuration
+  set:
+    networkPolicies.enabled: true
+    networkPolicies.default.enabled: true
+  asserts:
+  - hasDocuments:
+      count: 1
+  - containsDocument:
+      apiVersion: networking.k8s.io/v1
+      kind: NetworkPolicy
+      name: prometheus-fail2ban-exporter-unittest-default
+      namespace: testing
+  - notExists:
+      path: metadata.annotations
+  - equal:
+      path: metadata.labels
+      value:
+        app.kubernetes.io/instance: prometheus-fail2ban-exporter-unittest
+        app.kubernetes.io/managed-by: Helm
+        app.kubernetes.io/name: prometheus-fail2ban-exporter
+        app.kubernetes.io/version: 0.1.0
+        helm.sh/chart: prometheus-fail2ban-exporter-0.1.0
+  - equal:
+      path: spec.podSelector.matchLabels
+      value:
+        app.kubernetes.io/instance: prometheus-fail2ban-exporter-unittest
+        app.kubernetes.io/name: prometheus-fail2ban-exporter
+  - notExists:
+      path: spec.policyTypes
+  - notExists:
+      path: spec.egress
+  - notExists:
+      path: spec.ingress
+
+- it: Template networkPolicy 'default' with policyTypes, egress and ingress configuration
+  set:
+    networkPolicies.enabled: true
+    networkPolicies.default.enabled: true
+    networkPolicies.default.policyTypes:
+    - Egress
+    - Ingress
+    networkPolicies.default.ingress:
+    - from:
+      - namespaceSelector:
+          matchLabels:
+            kubernetes.io/metadata.name: khv-production
+        podSelector:
+          matchLabels:
+            app.kubernetes.io/name: prometheus
+    networkPolicies.default.egress:
+    - to:
+      - namespaceSelector:
+          matchLabels:
+            kubernetes.io/metadata.name: database
+        podSelector:
+          matchLabels:
+            app.kubernetes.io/name: oracle
+  asserts:
+  - equal:
+      path: spec.policyTypes
+      value:
+      - Egress
+      - Ingress
+  - equal:
+      path: spec.egress
+      value:
+      - to:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: database
+          podSelector:
+            matchLabels:
+              app.kubernetes.io/name: oracle
+  - equal:
+      path: spec.ingress
+      value:
+      - from:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: khv-production
+          podSelector:
+            matchLabels:
+              app.kubernetes.io/name: prometheus

values.yaml

@@ -270,9 +270,53 @@ podDisruptionBudget: {}
 #  maxUnavailable: 1
 #  minAvailable: 1
 
-## @section Network
-## @param networkPolicies Deploy network policies based on the used container network interface (CNI) implementation - like calico or weave.
-networkPolicies: {}
+## @section NetworkPolicies
+## @param networkPolicies.enabled Enable network policies in general.
+networkPolicies:
+  enabled: false
+
+  ## @param networkPolicies.default.enabled Enable the network policy for accessing the application by default. For example to scape the metrics.
+  ## @param networkPolicies.default.annotations Additional network policy annotations.
+  ## @param networkPolicies.default.labels Additional network policy labels.
+  ## @param networkPolicies.default.policyTypes List of policy types. Supported is ingress, egress or ingress and egress.
+  ## @param networkPolicies.default.egress Concrete egress network policy implementation.
+  ## @skip networkPolicies.default.egress Skip individual egress configuration.
+  ## @param networkPolicies.default.ingress Concrete ingress network policy implementation.
+  ## @skip networkPolicies.default.ingress Skip individual ingress configuration.
+  default:
+    enabled: false
+    annotations: {}
+    labels: {}
+    policyTypes: []
+    # - Egress
+    # - Ingress
+    egress: []
+    ingress: []
+    # Allow incoming HTTP traffic from prometheus.
+    #
+    # - from:
+    #   - namespaceSelector:
+    #       matchLabels:
+    #         kubernetes.io/metadata.name: monitoring
+    #     podSelector:
+    #       matchLabels:
+    #         app.kubernetes.io/name: prometheus
+    #   ports:
+    #   - port: http
+    #     protocol: TCP
+
+    # Allow incoming HTTP traffic from ingress-nginx.
+    #
+    # - from:
+    #   - namespaceSelector:
+    #       matchLabels:
+    #         kubernetes.io/metadata.name: ingress-nginx
+    #     podSelector:
+    #       matchLabels:
+    #         app.kubernetes.io/name: ingress-nginx
+    #   ports:
+    #   - port: http
+    #     protocol: TCP
 
 ## @section Prometheus
 prometheus: