[prom-label-proxy] kube-rbac-proxy support (#4624)

Co-authored-by: Jan-Otto Kröpke <github@jkroepke.de>
prometheus-community · Jul 6, 2024 · 094734b · 094734b
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diff --git a/charts/prom-label-proxy/Chart.yaml b/charts/prom-label-proxy/Chart.yaml
@@ -2,7 +2,7 @@ apiVersion: v2
 name: prom-label-proxy
 description: A proxy that enforces a given label in a given PromQL query.
 type: application
-version: 0.8.0
+version: 0.9.0
 appVersion: "v0.10.0"
 home: "https://github.com/prometheus-community/prom-label-proxy"
 keywords:

diff --git a/charts/prom-label-proxy/README.md b/charts/prom-label-proxy/README.md
@@ -48,3 +48,68 @@ See [Customizing the Chart Before Installing](https://helm.sh/docs/intro/using_h
 ```console
 helm show values prometheus-community/prom-label-proxy
 ```
+
+### kube-rbac-proxy
+
+You can enable `prom-label-proxy` endpoint protection using `kube-rbac-proxy`. By setting `kubeRBACProxy.enabled: true`, this chart will deploy one RBAC proxy container for `config.listenAddress`.
+
+With the below example `values.yaml` :
+
+```yaml
+config:
+  upstream: http://prometheus:9090
+  extraArgs:
+  - --enable-label-apis=true
+  - --header-name=X-Namespace
+
+kubeRBACProxy:
+  enabled: true
+  config:
+    authorization:
+      rewrites:
+        byHttpHeader:
+          name: X-Namespace
+      resourceAttributes:
+        apiVersion: v1
+        resource: namespaces
+        subresource: metrics
+        namespace: "{{ .Value }}"
+```
+
+To authorize access, authenticate your requests (via a `ServiceAccount` for example) with a `Role` attached such as:
+
+```yaml
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: tenant1-metrics-reader
+  namespace: tenant1
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: tenant1-metrics
+  namespace: tenant1
+rules:
+  - apiGroups: [ '' ]
+    resources:
+      - namespaces/metrics
+    verbs: [ "create", "get" ]
+---
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: tenant1-metrics-reader
+  namespace: tenant1
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: tenant1-metrics
+subjects:
+- kind: ServiceAccount
+  name: tenant1-metrics-reader
+  namespace: tenant1
+```
+
+See [kube-rbac-proxy examples](https://github.com/brancz/kube-rbac-proxy/tree/master/examples/rewrites) for more details.
diff --git a/charts/prom-label-proxy/ci/kube-rbac-proxy-values.yaml b/charts/prom-label-proxy/ci/kube-rbac-proxy-values.yaml
@@ -0,0 +1,18 @@
+config:
+  upstream: http://prometheus:9090
+  extraArgs:
+  - --enable-label-apis=true
+  - --header-name=X-Namespace
+
+kubeRBACProxy:
+  enabled: true
+  config:
+    authorization:
+      rewrites:
+        byHttpHeader:
+          name: X-Namespace
+      resourceAttributes:
+        apiVersion: v1
+        resource: namespaces
+        subresource: metrics
+        namespace: "{{ .Value }}"
diff --git a/charts/prom-label-proxy/templates/_helpers.tpl b/charts/prom-label-proxy/templates/_helpers.tpl
@@ -79,3 +79,11 @@ Return the appropriate apiVersion for rbac.
     {{- .Release.Namespace -}}
   {{- end -}}
 {{- end -}}
+
+
+{{/*
+The image to use for kubeRBACProxy
+*/}}
+{{- define "kubeRBACProxy.image" -}}
+{{- printf "%s:%s" .Values.kubeRBACProxy.image.repository .Values.kubeRBACProxy.image.tag }}
+{{- end }}
diff --git a/charts/prom-label-proxy/templates/clusterrole.yaml b/charts/prom-label-proxy/templates/clusterrole.yaml
@@ -0,0 +1,17 @@
+{{- if .Values.kubeRBACProxy.enabled -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: {{ include "prom-label-proxy.fullname" . }}
+  labels:
+    {{- include "prom-label-proxy.labels" . | nindent 4 }}
+rules:
+  - apiGroups: [ "authentication.k8s.io" ]
+    resources:
+      - tokenreviews
+    verbs: [ "create" ]
+  - apiGroups: [ "authorization.k8s.io" ]
+    resources:
+      - subjectaccessreviews
+    verbs: [ "create" ]
+{{- end -}}
diff --git a/charts/prom-label-proxy/templates/clusterrolebinding.yaml b/charts/prom-label-proxy/templates/clusterrolebinding.yaml
@@ -0,0 +1,16 @@
+{{- if .Values.kubeRBACProxy.enabled -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  labels:
+    {{- include "prom-label-proxy.labels" . | nindent 4 }}
+  name: {{ template "prom-label-proxy.fullname" . }}
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: {{ template "prom-label-proxy.fullname" . }}
+subjects:
+- kind: ServiceAccount
+  name: {{ template "prom-label-proxy.serviceAccountName" . }}
+  namespace: {{ template "prom-label-proxy.namespace" . }}
+{{- end -}}
diff --git a/charts/prom-label-proxy/templates/deployment.yaml b/charts/prom-label-proxy/templates/deployment.yaml
@@ -12,9 +12,14 @@ spec:
       {{- include "prom-label-proxy.selectorLabels" . | nindent 6 }}
   template:
     metadata:
-      {{- with .Values.podAnnotations }}
+      {{- if or .Values.podAnnotations (and .Values.kubeRBACProxy.enabled .Values.kubeRBACProxy.config) }}
       annotations:
+        {{- with .Values.podAnnotations }}
         {{- toYaml . | nindent 8 }}
+        {{- end }}
+        {{- if and .Values.kubeRBACProxy.enabled .Values.kubeRBACProxy.config }}
+        checksum/config: {{ .Values.kubeRBACProxy.config | toJson | sha256sum }}
+        {{- end }}
       {{- end }}
       labels:
         {{- include "prom-label-proxy.selectorLabels" . | nindent 8 }}
@@ -30,6 +35,7 @@ spec:
       securityContext:
         {{- toYaml .Values.podSecurityContext | nindent 8 }}
       containers:
+      {{- $configListenPort := tpl .Values.config.listenAddress $ | splitList ":" | last }}
         - name: {{ .Chart.Name }}
           securityContext:
             {{- toYaml .Values.securityContext | nindent 12 }}
@@ -47,7 +53,7 @@ spec:
             {{- end }}
           ports:
             - name: http
-              containerPort: {{ splitList ":" .Values.config.listenAddress | last }}
+              containerPort: {{ $configListenPort }}
               protocol: TCP
             {{- if .Values.metrics.enabled }}
             - name: http-metrics
@@ -60,6 +66,45 @@ spec:
             {{- toYaml .Values.readinessProbe | nindent 12 }}
           resources:
             {{- toYaml .Values.resources | nindent 12 }}
+        {{-  if .Values.kubeRBACProxy.enabled  }}
+        - name: kube-rbac-proxy
+          args:
+          {{-  if .Values.kubeRBACProxy.extraArgs  }}
+          {{- .Values.kubeRBACProxy.extraArgs | toYaml | nindent 10 }}
+          {{-  end  }}
+          - --secure-listen-address=:{{ .Values.kubeRBACProxy.port }}
+          - --upstream=http://127.0.0.1:{{ $configListenPort }}/
+          - --proxy-endpoints-port=8888
+          {{- if .Values.kubeRBACProxy.config }}
+          - --config-file=/etc/kube-rbac-proxy-config/config-file.yaml
+          {{- end }}
+          volumeMounts:
+            - name: kube-rbac-proxy-config
+              mountPath: /etc/kube-rbac-proxy-config
+            {{- with .Values.kubeRBACProxy.volumeMounts }}
+            {{- toYaml . | nindent 12 }}
+            {{- end }}
+          imagePullPolicy: {{ .Values.kubeRBACProxy.image.pullPolicy }}
+          image: {{ include "kubeRBACProxy.image" . }}
+          ports:
+            - containerPort: {{ .Values.kubeRBACProxy.port }}
+              name: krp
+            - containerPort: 8888
+              name: krp-healthz
+          readinessProbe:
+            httpGet:
+              scheme: HTTPS
+              port: 8888
+              path: healthz
+            initialDelaySeconds: 5
+            timeoutSeconds: 5
+          {{- if .Values.kubeRBACProxy.resources }}
+          resources: {{ toYaml .Values.kubeRBACProxy.resources | nindent 10 }}
+          {{- end }}
+          {{- if .Values.kubeRBACProxy.containerSecurityContext }}
+          securityContext: {{ toYaml .Values.kubeRBACProxy.containerSecurityContext | nindent 12 }}
+          {{- end }}
+      {{- end }}
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}
@@ -72,3 +117,9 @@ spec:
       tolerations:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      {{-  if and .Values.kubeRBACProxy.enabled .Values.kubeRBACProxy.config }}
+      volumes:
+        - name: kube-rbac-proxy-config
+          configMap:
+            name: {{ template "prom-label-proxy.fullname" . }}-rbac-config
+      {{- end }}
diff --git a/charts/prom-label-proxy/templates/rbac-configmap.yaml b/charts/prom-label-proxy/templates/rbac-configmap.yaml
@@ -0,0 +1,15 @@
+{{- if and .Values.kubeRBACProxy.enabled .Values.kubeRBACProxy.config }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ template "prom-label-proxy.fullname" . }}-rbac-config
+  namespace: {{ template "prom-label-proxy.namespace" . }}
+  labels: {{- include "prom-label-proxy.labels" . | nindent 4 }}
+  {{- if .Values.annotations }}
+  annotations:
+    {{ toYaml .Values.annotations | nindent 4 }}
+  {{- end }}
+data:
+  config-file.yaml: |
+    {{- .Values.kubeRBACProxy.config | toYaml | nindent 4 }}
+{{- end }}
diff --git a/charts/prom-label-proxy/templates/service.yaml b/charts/prom-label-proxy/templates/service.yaml
@@ -13,7 +13,11 @@ spec:
   type: {{ .Values.service.type }}
   ports:
     - port: {{ .Values.service.port }}
+      {{-  if .Values.kubeRBACProxy.enabled  }}
+      targetPort: krp
+      {{- else }}
       targetPort: http
+      {{- end }}
       protocol: TCP
       name: http
       {{- if (and (eq .Values.service.type "NodePort") (not (empty .Values.service.nodePort))) }}

diff --git a/charts/prom-label-proxy/values.yaml b/charts/prom-label-proxy/values.yaml
@@ -198,3 +198,61 @@ metrics:
 
     # Additional settings for Endpoint.
     additionalEndpointConfigs: {}
+
+# Configure kube-rbac-proxy. When enabled, creates one kube-rbac-proxy container.
+# The requests are served through the same service but requests are then HTTPS.
+kubeRBACProxy:
+  enabled: false
+
+  # Configuration see [here](https://github.com/brancz/kube-rbac-proxy?tab=readme-ov-file#usage)
+  config: {}
+  #  authorization:
+  #    rewrites:
+  #      byHttpHeader:
+  #        name: X-Namespace
+  #    resourceAttributes:
+  #      resource: pods
+  #      subresource: metrics
+  #      namespace: "{{ .Value }}"
+
+  image:
+    repository: quay.io/brancz/kube-rbac-proxy
+    tag: v0.18.0
+    pullPolicy: IfNotPresent
+
+  # List of additional cli arguments to configure kube-rbac-prxy
+  # for example: --tls-cipher-suites, --log-file, etc.
+  # all the possible args can be found here: https://github.com/brancz/kube-rbac-proxy#usage
+  extraArgs: []
+
+  # targetPort of service
+  port: 8100
+
+  ## Specify security settings for a Container
+  ## Allows overrides and additional options compared to (Pod) securityContext
+  ## Ref: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/#set-the-security-context-for-a-container
+  containerSecurityContext:
+    readOnlyRootFilesystem: true
+    allowPrivilegeEscalation: false
+    capabilities:
+      drop:
+      - ALL
+
+  resources: {}
+    # We usually recommend not to specify default resources and to leave this as a conscious
+    # choice for the user. This also increases chances charts run on environments with little
+    # resources, such as Minikube. If you do want to specify resources, uncomment the following
+    # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
+    # limits:
+    #  cpu: 100m
+    #  memory: 64Mi
+    # requests:
+    #  cpu: 10m
+    #  memory: 32Mi
+
+  ## volumeMounts enables mounting custom volumes in rbac-proxy containers
+  ## Useful for TLS certificates and keys
+  volumeMounts: []
+    # - mountPath: /etc/tls
+    #   name: kube-rbac-proxy-tls
+    #   readOnly: true