api-gateway: allow controller to bind PodSecurityPolicy to ServiceAcc…

…ounts that it creates (#1672) (#1682)

* Add PodSecurityPolicy for all Gateway Deployments

* Allow API gateway controller to manage roles + bindings

* Add entry to CHANGELOG

* Consolidate controller ClusterRole mods for enablePodSecurityPolicies

* Update/add unit test coverage for controller ClusterRole

* Check for additional verbs on cluster role

Co-authored-by: Nathan Coleman <nathan.coleman@hashicorp.com>

CHANGELOG.md

@@ -6,6 +6,7 @@ IMPROVEMENTS:
   * API Gateway: Allow controller to read MeshServices for use as a route backend. [[GH-1574](https://github.com/hashicorp/consul-k8s/pull/1574)]
   * API Gateway: Add `tolerations` to `apiGateway.managedGatewayClass` and `apiGateway.controller` [[GH-1650](https://github.com/hashicorp/consul-k8s/pull/1650)]
   * API Gateway: Create PodSecurityPolicy for controller when `global.enablePodSecurityPolicies=true`. [[GH-1656](https://github.com/hashicorp/consul-k8s/pull/1656)]
+  * API Gateway: Create PodSecurityPolicy and allow controller to bind it to ServiceAccounts that it creates for Gateway Deployments when `global.enablePodSecurityPolicies=true`. [[GH-1672](https://github.com/hashicorp/consul-k8s/pull/1672)]
 
 ## 0.49.0 (September 30, 2022)
 

charts/consul/templates/api-gateway-controller-clusterrole.yaml

@@ -245,11 +245,21 @@ rules:
   - patch
   - update
 {{- if .Values.global.enablePodSecurityPolicies }}
-- apiGroups: ["policy"]
-  resources: ["podsecuritypolicies"]
-  resourceNames:
-    - {{ template "consul.fullname" . }}-api-gateway-controller
+- apiGroups:
+  - policy
+  resources:
+  - podsecuritypolicies
+  verbs:
+  - use
+- apiGroups:
+  - rbac.authorization.k8s.io
+  resources:
+  - roles
+  - rolebindings
   verbs:
-    - use
+  - create
+  - get
+  - list
+  - watch
 {{- end }}
 {{- end }}

charts/consul/templates/api-gateway-gatewayclassconfig.yaml

@@ -15,6 +15,9 @@ spec:
       {{- if .Values.global.acls.manageSystemACLs }}
       managed: true
       method: {{ template "consul.fullname" . }}-k8s-auth-method
+      {{- if .Values.global.enablePodSecurityPolicies }}
+      podSecurityPolicy: {{ template "consul.fullname" . }}-api-gateway
+      {{- end }}
       {{- end }}
     {{- if .Values.global.tls.enabled }}
     scheme: https

charts/consul/templates/api-gateway-podsecuritypolicy.yaml

@@ -0,0 +1,45 @@
+{{- if and .Values.apiGateway.enabled .Values.global.enablePodSecurityPolicies }}
+apiVersion: policy/v1beta1
+kind: PodSecurityPolicy
+metadata:
+  name: {{ template "consul.fullname" . }}-api-gateway
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app: {{ template "consul.name" . }}
+    chart: {{ template "consul.chart" . }}
+    heritage: {{ .Release.Service }}
+    release: {{ .Release.Name }}
+    component: api-gateway-controller
+spec:
+  privileged: false
+  # Required to prevent escalations to root.
+  allowPrivilegeEscalation: false
+  # This is redundant with non-root + disallow privilege escalation,
+  # but we can provide it for defense in depth.
+  requiredDropCapabilities:
+    - ALL
+  # Allow core volume types.
+  volumes:
+    - 'configMap'
+    - 'emptyDir'
+    - 'projected'
+    - 'secret'
+    - 'downwardAPI'
+  allowedCapabilities:
+    - NET_BIND_SERVICE
+  hostNetwork: false
+  hostIPC: false
+  hostPID: false
+  hostPorts:
+    - max: 65535
+      min: 1025
+  runAsUser:
+    rule: 'RunAsAny'
+  seLinux:
+    rule: 'RunAsAny'
+  supplementalGroups:
+    rule: 'RunAsAny'
+  fsGroup:
+    rule: 'RunAsAny'
+  readOnlyRootFilesystem: true
+{{- end }}

charts/consul/test/unit/api-gateway-controller-clusterrole.bats

@@ -20,14 +20,26 @@ load _helpers
   [ "${actual}" = "true" ]
 }
 
-@test "apiGateway/ClusterRole: uses PodSecurityPolicy with apiGateway.enabled=true and global.enablePodSecurityPolicies=true" {
+@test "apiGateway/ClusterRole: can use podsecuritypolicies with apiGateway.enabled=true and global.enablePodSecurityPolicies=true" {
   cd `chart_dir`
   local actual=$(helm template \
       -s templates/api-gateway-controller-clusterrole.yaml \
       --set 'global.enablePodSecurityPolicies=true' \
       --set 'apiGateway.enabled=true' \
       --set 'apiGateway.image=foo' \
       . | tee /dev/stderr |
-      yq '.rules[] | select((.resourceNames[0] == "release-name-consul-api-gateway-controller") and (.resources[0] == "podsecuritypolicies")) | length > 0' | tee /dev/stderr)
+      yq '.rules[] | select((.resources[0] == "podsecuritypolicies") and (.verbs[0] == "use")) | length > 0' | tee /dev/stderr)
+  [ "${actual}" = "true" ]
+}
+
+@test "apiGateway/ClusterRole: can create roles and rolebindings with apiGateway.enabled=true and global.enablePodSecurityPolicies=true" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/api-gateway-controller-clusterrole.yaml \
+      --set 'global.enablePodSecurityPolicies=true' \
+      --set 'apiGateway.enabled=true' \
+      --set 'apiGateway.image=foo' \
+      . | tee /dev/stderr |
+      yq '.rules[] | select((.resources[0] == "roles") and (.resources[1] == "rolebindings") and (.verbs | contains(["create","get","list","watch"]))) | length > 0' | tee /dev/stderr)
   [ "${actual}" = "true" ]
 }