docs(README): add section network policies

.gitea/workflows/generate-readme.yaml

@@ -15,7 +15,7 @@ on:
 jobs:
   generate-parameters:
     container:
-      image: docker.io/library/node:22.13.1-alpine
+      image: docker.io/library/node:23.8.0-alpine
     runs-on:
     - ubuntu-latest
     steps:

.gitea/workflows/helm.yaml

@@ -13,7 +13,7 @@ on:
 jobs:
   helm-lint:
     container:
-      image: docker.io/volkerraschek/helm:3.16.4
+      image: docker.io/volkerraschek/helm:3.17.1
     runs-on:
     - ubuntu-latest
     steps:
@@ -28,7 +28,7 @@ jobs:
 
   helm-unittest:
     container:
-      image: docker.io/volkerraschek/helm:3.16.4
+      image: docker.io/volkerraschek/helm:3.17.1
     runs-on:
     - ubuntu-latest
     steps:

.gitea/workflows/markdown-linters.yaml

@@ -15,7 +15,7 @@ on:
 jobs:
   markdown-link-checker:
     container:
-      image: docker.io/library/node:22.13.1-alpine
+      image: docker.io/library/node:23.8.0-alpine
     runs-on:
     - ubuntu-latest
     steps:
@@ -31,7 +31,7 @@ jobs:
 
   markdown-lint:
     container:
-      image: docker.io/library/node:22.13.1-alpine
+      image: docker.io/library/node:23.8.0-alpine
     runs-on:
     - ubuntu-latest
     steps:

.gitea/workflows/release.yaml

@@ -8,7 +8,7 @@ on:
 jobs:
   publish-chart:
     container:
-      image: docker.io/volkerraschek/helm:3.16.4
+      image: docker.io/volkerraschek/helm:3.17.1
     runs-on: ubuntu-latest
     steps:
       - name: Install tooling

README.md

@@ -68,7 +68,7 @@ cannot use the available CPU time to perform computing operations.
 
 The application must be informed that despite several CPUs only a part (limit) of the available computing time is
 available. As this is a Golang application, this can be implemented using `GOMAXPROCS`. The following example is one way
-of defining `GOMAXPROCS` automatically based on the defined CPU limit like `100m`. Please keep in mind, that the CFS
+of defining `GOMAXPROCS` automatically based on the defined CPU limit like `1000m`. Please keep in mind, that the CFS
 rate of `100ms` - default on each kubernetes node, is also very important to avoid CPU throttling.
 
 Further information about this topic can be found [here](https://kanishk.io/posts/cpu-throttling-in-containerized-go-apps/).
@@ -76,6 +76,8 @@ Further information about this topic can be found [here](https://kanishk.io/post
 > [!NOTE]
 > The environment variable `GOMAXPROCS` is set automatically, when a CPU limit is defined. An explicit configuration is
 > not anymore required.
+>
+> Please take care the a CPU limit < `1000m` can also lead to CPU throttling. Please read the linked documentation carefully.
 
 ```bash
 helm install prometheus-fail2ban-exporter prometheus-exporters/prometheus-fail2ban-exporter \
@@ -83,7 +85,7 @@ helm install prometheus-fail2ban-exporter prometheus-exporters/prometheus-fail2b
   --set 'prometheus.metrics.serviceMonitor.enabled=true' \
   --set 'daemonSet.fail2banExporter.env.name=GOMAXPROCS' \
   --set 'daemonSet.fail2banExporter.env.valueFrom.resourceFieldRef.resource=limits.cpu' \
-  --set 'daemonSet.fail2banExporter.resources.limits.cpu=100m'
+  --set 'daemonSet.fail2banExporter.resources.limits.cpu=1000m'
 ```
 
 <!--
@@ -146,6 +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
@@ -229,11 +286,17 @@ helm install prometheus-fail2ban-exporter prometheus-exporters/prometheus-fail2b
 | --------------------- | ---------------------- | ----- |
 | `podDisruptionBudget` | Pod disruption budget. | `{}`  |
 
-### Network
+### NetworkPolicies
 
-| Name              | Description                                                                                                        | Value |
-| ----------------- | ------------------------------------------------------------------------------------------------------------------ | ----- |
-| `networkPolicies` | Deploy network policies based on the used container network interface (CNI) implementation - like calico or weave. | `{}`  |
+| Name                                  | Description                                                                                           | Value   |
+| ------------------------------------- | ----------------------------------------------------------------------------------------------------- | ------- |
+| `networkPolicies.enabled`             | Enable network policies in general.                                                                   | `false` |
+| `networkPolicies.default.enabled`     | Enable the network policy for accessing the application by default. For example to scape the metrics. | `false` |
+| `networkPolicies.default.annotations` | Additional network policy annotations.                                                                | `{}`    |
+| `networkPolicies.default.labels`      | Additional network policy labels.                                                                     | `{}`    |
+| `networkPolicies.default.policyTypes` | List of policy types. Supported is ingress, egress or ingress and egress.                             | `[]`    |
+| `networkPolicies.default.egress`      | Concrete egress network policy implementation.                                                        | `[]`    |
+| `networkPolicies.default.ingress`     | Concrete ingress network policy implementation.                                                       | `[]`    |
 
 ### Prometheus
 

package.json

@@ -16,6 +16,6 @@
   "devDependencies": {
     "@bitnami/readme-generator-for-helm": "^2.5.0",
     "markdown-link-check": "^3.13.6",
-    "markdownlint-cli": "^0.43.0"
+    "markdownlint-cli": "^0.44.0"
   }
 }

renovate.json

@@ -1,6 +1,8 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "assignees": [ "volker.raschek" ],
+  "assignees": [
+    "volker.raschek"
+  ],
   "customManagers": [
     {
       "fileMatch": [
@@ -25,24 +27,45 @@
       "versioningTemplate": "semver"
     }
   ],
-  "labels": [ "renovate" ],
+  "labels": [
+    "renovate"
+  ],
   "lockFileMaintenance": {
+    "addLabels": [
+      "renovate/automerge",
+      "renovate/lockFileMaintenance"
+    ],
+    "automerge": true,
+    "enabled": true
+  },
+  "npm": {
     "enabled": true
   },
   "packageRules": [
     {
-      "addLabels": [ "renovate/automerge", "renovate/npm" ],
+      "addLabels": [
+        "renovate/automerge",
+        "renovate/npm"
+      ],
       "automerge": true,
       "matchPackageNames": [
+        "@bitnami/readme-generator-for-helm",
         "markdownlint-cli",
-        "markdown-link-check",
-        "@bitnami/readme-generator-for-helm"
+        "markdown-link-check"
       ],
-      "matchManagers": [ "npm" ],
-      "matchUpdateTypes": [ "minor", "patch"]
+      "matchManagers": [
+        "npm"
+      ],
+      "matchUpdateTypes": [
+        "minor",
+        "patch"
+      ]
     },
     {
-      "addLabels": [ "renovate/automerge", "renovate/container" ],
+      "addLabels": [
+        "renovate/automerge",
+        "renovate/container"
+      ],
       "automerge": true,
       "excludePackagePatterns": [
         "volker.raschek/prometheus-fail2ban-exporter"
@@ -54,6 +77,21 @@
         "minor",
         "patch"
       ]
+    },
+    {
+      "addLabels": [
+        "renovate/automerge",
+        "renovate/documentation"
+      ],
+      "automerge": true,
+      "matchDepNames": [
+        "volker.raschek/prometheus-fail2ban-exporter-charts"
+      ],
+      "matchUpdateTypes": [
+        "major",
+        "minor",
+        "patch"
+      ]
     }
   ],
   "rebaseLabel": "renovate/rebase",

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: