feat: add ability to restrict required-probes constraint to container…

…s in pods selected by a service

Signed-off-by: Craig Trought <k8s@trought.ca>

artifacthub/library/general/requiredprobes/1.1.0/artifacthub-pkg.yml

@@ -0,0 +1,22 @@
+version: 1.1.0
+name: k8srequiredprobes
+displayName: Required Probes
+createdAt: "2023-01-04T23:20:17Z"
+description: Requires Pods to have readiness and/or liveness probes.
+digest: 1f871f3eb3e25749d3d6872736253ae2cd2dc394ed9b402bb1560cdd28613666
+license: Apache-2.0
+homeURL: https://open-policy-agent.github.io/gatekeeper-library/website/requiredprobes
+keywords:
+    - gatekeeper
+    - open-policy-agent
+    - policies
+readme: |-
+    # Required Probes
+    Requires Pods to have readiness and/or liveness probes.
+install: |-
+    ### Usage
+    ```shell
+    kubectl apply -f https://raw.githubusercontent.com/open-policy-agent/gatekeeper-library/master/artifacthub/library/general/requiredprobes/1.1.0/template.yaml
+    ```
+provider:
+    name: Gatekeeper Library

artifacthub/library/general/requiredprobes/1.1.0/kustomization.yaml

@@ -0,0 +1,2 @@
+resources:
+  - template.yaml

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes-on-service/constraint.yaml

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+apiVersion: constraints.gatekeeper.sh/v1beta1
+kind: K8sRequiredProbes
+metadata:
+  name: must-have-probes-on-service
+spec:
+  match:
+    kinds:
+      - apiGroups: [""]
+        kinds: ["Pod"]
+  parameters:
+    onlyServices: true
+    probes: ["readinessProbe", "livenessProbe"]
+    probeTypes: ["tcpSocket", "httpGet", "exec"]
+    customViolationMessage: "See https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes for more info."

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes-on-service/example_allowed_with_service.yaml

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+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod1
+  namespace: default
+  labels:
+    app.kubernetes.io/name: tomcat
+spec:
+  containers:
+  - name: tomcat
+    image: tomcat
+    ports:
+    - containerPort: 8080
+      name: tomcat-http
+    livenessProbe:
+      tcpSocket:
+        port: 80
+      initialDelaySeconds: 5
+      periodSeconds: 10
+    readinessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 5
+      periodSeconds: 10
+  volumes:
+  - name: cache-volume
+    emptyDir: {}

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes-on-service/example_allowed_without_service.yaml

@@ -0,0 +1,17 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod1
+  namespace: default
+  labels:
+    app.kubernetes.io/name: tomcat-no-svc
+    second-label: "example"
+spec:
+  containers:
+  - name: tomcat
+    image: tomcat
+    ports:
+    - containerPort: 8080
+  volumes:
+  - name: cache-volume
+    emptyDir: {}

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes-on-service/example_disallowed_with_service.yaml

@@ -0,0 +1,35 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod1
+  namespace: default
+  labels:
+    app.kubernetes.io/name: tomcat
+    second-label: "example"
+spec:
+  containers:
+  - name: nginx-1
+    image: nginx:1.7.9
+    ports:
+    - containerPort: 80
+    livenessProbe:
+      # tcpSocket:
+      #   port: 80
+      # initialDelaySeconds: 5
+      # periodSeconds: 10
+    volumeMounts:
+    - mountPath: /tmp/cache
+      name: cache-volume
+  - name: tomcat
+    image: tomcat
+    ports:
+    - containerPort: 8080
+      name: tomcat-http
+    readinessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 5
+      periodSeconds: 10
+  volumes:
+  - name: cache-volume
+    emptyDir: {}

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes-on-service/inventory.yaml

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+apiVersion: v1
+kind: Service
+metadata:
+  name: tomcat-service
+  namespace: default
+spec:
+  selector:
+    app.kubernetes.io/name: tomcat
+  ports:
+  - name: name-of-service-port
+    protocol: TCP
+    port: 80
+    targetPort: tomcat-http

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes/constraint.yaml

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+apiVersion: constraints.gatekeeper.sh/v1beta1
+kind: K8sRequiredProbes
+metadata:
+  name: must-have-probes
+spec:
+  match:
+    kinds:
+      - apiGroups: [""]
+        kinds: ["Pod"]
+  parameters:
+    onlyServices: false
+    probes: ["readinessProbe", "livenessProbe"]
+    probeTypes: ["tcpSocket", "httpGet", "exec"]

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes/example_allowed.yaml

@@ -0,0 +1,23 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod1
+spec:
+  containers:
+  - name: tomcat
+    image: tomcat
+    ports:
+    - containerPort: 8080
+    livenessProbe:
+      tcpSocket:
+        port: 80
+      initialDelaySeconds: 5
+      periodSeconds: 10
+    readinessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 5
+      periodSeconds: 10
+  volumes:
+  - name: cache-volume
+    emptyDir: {}

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes/example_disallowed.yaml

@@ -0,0 +1,30 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod1
+spec:
+  containers:
+  - name: nginx-1
+    image: nginx:1.7.9
+    ports:
+    - containerPort: 80
+    livenessProbe:
+      # tcpSocket:
+      #   port: 80
+      # initialDelaySeconds: 5
+      # periodSeconds: 10
+    volumeMounts:
+    - mountPath: /tmp/cache
+      name: cache-volume
+  - name: tomcat
+    image: tomcat
+    ports:
+    - containerPort: 8080
+    readinessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 5
+      periodSeconds: 10
+  volumes:
+  - name: cache-volume
+    emptyDir: {}

artifacthub/library/general/requiredprobes/1.1.0/samples/must-have-probes/example_disallowed2.yaml

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+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod2
+spec:
+  containers:
+  - name: nginx-1
+    image: nginx:1.7.9
+    ports:
+    - containerPort: 80
+    readinessProbe:
+    # httpGet:
+    #   path: /
+    #   port: 80
+    # initialDelaySeconds: 5
+    # periodSeconds: 10
+    livenessProbe:
+      tcpSocket:
+        port: 80
+      initialDelaySeconds: 5
+      periodSeconds: 10
+    volumeMounts:
+    - mountPath: /tmp/cache
+      name: cache-volume
+  - name: tomcat
+    image: tomcat
+    ports:
+    - containerPort: 8080
+    readinessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 5
+      periodSeconds: 10
+    # livenessProbe:
+    #   tcpSocket:
+    #     port: 8080
+    #   initialDelaySeconds: 5
+    #   periodSeconds: 10
+  volumes:
+  - name: cache-volume
+    emptyDir: {}

artifacthub/library/general/requiredprobes/1.1.0/suite.yaml

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+kind: Suite
+apiVersion: test.gatekeeper.sh/v1alpha1
+metadata:
+  name: containerprobes
+tests:
+- name: container-probes
+  template: template.yaml
+  constraint: samples/must-have-probes/constraint.yaml
+  cases:
+  - name: example-allowed
+    object: samples/must-have-probes/example_allowed.yaml
+    assertions:
+    - violations: no
+  - name: example-disallowed
+    object: samples/must-have-probes/example_disallowed.yaml
+    assertions:
+    - violations: yes
+  - name: example-disallowed2
+    object: samples/must-have-probes/example_disallowed2.yaml
+    assertions:
+    - violations: yes
+- name: container-probes-only-services
+  template: template.yaml
+  constraint: samples/must-have-probes-on-service/constraint.yaml
+  cases:
+  - name: example-allowed-without-service
+    object: samples/must-have-probes-on-service/example_allowed_without_service.yaml
+    inventory:
+    - samples/must-have-probes-on-service/inventory.yaml
+    assertions:
+    - violations: no
+  - name: example-allowed-with-service
+    object: samples/must-have-probes-on-service/example_allowed_with_service.yaml
+    inventory:
+    - samples/must-have-probes-on-service/inventory.yaml
+    assertions:
+    - violations: no
+  - name: example-disallowed-with-service
+    object: samples/must-have-probes-on-service/example_disallowed_with_service.yaml
+    inventory:
+    - samples/must-have-probes-on-service/inventory.yaml
+    assertions:
+    - violations: yes

artifacthub/library/general/requiredprobes/1.1.0/template.yaml

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+apiVersion: templates.gatekeeper.sh/v1
+kind: ConstraintTemplate
+metadata:
+  name: k8srequiredprobes
+  annotations:
+    metadata.gatekeeper.sh/title: "Required Probes"
+    metadata.gatekeeper.sh/version: 1.1.0
+    metadata.gatekeeper.sh/requiresSyncData: |
+      "[
+        [
+          {
+            "groups":[""],
+            "versions": ["v1"],
+            "kinds": ["Service"]
+          }
+        ]
+      ]"
+    description: Requires Pods to have readiness and/or liveness probes.
+spec:
+  crd:
+    spec:
+      names:
+        kind: K8sRequiredProbes
+      validation:
+        openAPIV3Schema:
+          type: object
+          properties:
+            onlyServices:
+              description: "Only apply to pods that are selected by a service"
+              type: boolean
+            probes:
+              description: "A list of probes that are required (ex: `readinessProbe`)"
+              type: array
+              items:
+                type: string
+            probeTypes:
+              description: "The probe must define a field listed in `probeType` in order to satisfy the constraint (ex. `tcpSocket` satisfies `['tcpSocket', 'exec']`)"
+              type: array
+              items:
+                type: string
+            customViolationMessage:
+              type: string
+              description: >-
+                Custom error message generated by a violation that is appended to the standard violation message
+  targets:
+    - target: admission.k8s.gatekeeper.sh
+      rego: |
+        package k8srequiredprobes
+
+        probe_type_set = probe_types {
+            probe_types := {type | type := input.parameters.probeTypes[_]}
+        }
+
+        violation[{"msg": msg}] {
+            not input.parameters.onlyServices
+            container := input.review.object.spec.containers[_]
+            probe := input.parameters.probes[_]
+            probe_is_missing(container, probe)
+            custom_msg := object.get(input.parameters, "customViolationMessage", "")
+            msg := trim(sprintf("Container <%v> in this <%v> has no <%v>. %v", [container.name, input.review.kind.kind, probe, custom_msg]), " ")
+        }
+
+        violation[{"msg": msg}] {
+            input.parameters.onlyServices
+            container := input.review.object.spec.containers[_]
+            probe := input.parameters.probes[_]
+            probe_is_missing(container, probe)
+
+            obj := input.review.object
+            svc := data.inventory.namespace[obj.metadata.namespace]["v1"]["Service"][_]
+            matchLabels := { [label, value] | some label; value := svc.spec.selector[label] }
+            labels := { [label, value] | some label; value := obj.metadata.labels[label] }
+            count(matchLabels - labels) == 0
+            matching_ports := [p | p := svc.spec.ports[_].targetPort; has_port(p, container)]
+            count(matching_ports) > 0
+
+            custom_msg := object.get(input.parameters, "customViolationMessage", "")
+            msg := trim(sprintf("Container <%v> in this <%v> has no <%v> and is selected by service <%v> with targetPort(s) %v. %v", [container.name, input.review.kind.kind, probe, svc.metadata.name, matching_ports, custom_msg]), " ")
+        }
+
+        has_port(targetPort, container){
+            targetPort == container.ports[_].containerPort
+        }
+
+        has_port(targetPort, container){
+            targetPort == container.ports[_].name
+        }
+
+        probe_is_missing(ctr, probe) = true {
+            not ctr[probe]
+        }
+
+        probe_is_missing(ctr, probe) = true {
+            probe_field_empty(ctr, probe)
+        }
+
+        probe_field_empty(ctr, probe) = true {
+            probe_fields := {field | ctr[probe][field]}
+            diff_fields := probe_type_set - probe_fields
+            count(diff_fields) == count(probe_type_set)
+        }