add explicit securitycontexts to controllers

Add explicit, secure securityContexts for all managers except CAPD, which is privileged and for testing purposes. These securityContexts do not change the configuration, just make it explicit and enforced, except for the seccompPolicy which changes from Unconfined to RuntimeDefault. Syscalls filtered by RuntimeDefault policy are 95% namespaced and require capabilities (which we drop) in the first place, so no practical change there either.
kubernetes-sigs · Jan 5, 2023 · c101a2e · c101a2e
1 parent df9c56c
commit c101a2e
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Showing 5 changed files with 143 additions and 93 deletions.
diff --git a/bootstrap/kubeadm/config/manager/manager.yaml b/bootstrap/kubeadm/config/manager/manager.yaml
@@ -16,31 +16,43 @@ spec:
         control-plane: controller-manager
     spec:
       containers:
-      - command:
-        - /manager
-        args:
-        - "--leader-elect"
-        - "--metrics-bind-addr=localhost:8080"
-        - "--feature-gates=MachinePool=${EXP_MACHINE_POOL:=false},KubeadmBootstrapFormatIgnition=${EXP_KUBEADM_BOOTSTRAP_FORMAT_IGNITION:=false}"
-        - "--bootstrap-token-ttl=${KUBEADM_BOOTSTRAP_TOKEN_TTL:=15m}"
-        image: controller:latest
-        name: manager
-        ports:
-        - containerPort: 9440
-          name: healthz
-          protocol: TCP
-        readinessProbe:
-          httpGet:
-            path: /readyz
-            port: healthz
-        livenessProbe:
-          httpGet:
-            path: /healthz
-            port: healthz
+        - command:
+            - /manager
+          args:
+            - "--leader-elect"
+            - "--metrics-bind-addr=localhost:8080"
+            - "--feature-gates=MachinePool=${EXP_MACHINE_POOL:=false},KubeadmBootstrapFormatIgnition=${EXP_KUBEADM_BOOTSTRAP_FORMAT_IGNITION:=false}"
+            - "--bootstrap-token-ttl=${KUBEADM_BOOTSTRAP_TOKEN_TTL:=15m}"
+          image: controller:latest
+          name: manager
+          ports:
+            - containerPort: 9440
+              name: healthz
+              protocol: TCP
+          readinessProbe:
+            httpGet:
+              path: /readyz
+              port: healthz
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: healthz
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - ALL
+            privileged: false
+            runAsUser: 65532
+            runAsGroup: 65532
       terminationGracePeriodSeconds: 10
       serviceAccountName: manager
       tolerations:
         - effect: NoSchedule
           key: node-role.kubernetes.io/master
         - effect: NoSchedule
           key: node-role.kubernetes.io/control-plane
+      securityContext:
+        runAsNonRoot: true
+        seccompProfile:
+          type: RuntimeDefault
diff --git a/config/manager/manager.yaml b/config/manager/manager.yaml
@@ -17,43 +17,55 @@ spec:
         control-plane: controller-manager
     spec:
       containers:
-      - command:
-        - /manager
-        args:
-        - "--leader-elect"
-        - "--metrics-bind-addr=localhost:8080"
-        - "--feature-gates=MachinePool=${EXP_MACHINE_POOL:=false},ClusterResourceSet=${EXP_CLUSTER_RESOURCE_SET:=false},ClusterTopology=${CLUSTER_TOPOLOGY:=false},RuntimeSDK=${EXP_RUNTIME_SDK:=false}"
-        image: controller:latest
-        name: manager
-        env:
-        - name: POD_NAMESPACE
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.namespace
-        - name: POD_NAME
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.name
-        - name: POD_UID
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.uid
-        ports:
-        - containerPort: 9440
-          name: healthz
-          protocol: TCP
-        readinessProbe:
-          httpGet:
-            path: /readyz
-            port: healthz
-        livenessProbe:
-          httpGet:
-            path: /healthz
-            port: healthz
+        - command:
+            - /manager
+          args:
+            - "--leader-elect"
+            - "--metrics-bind-addr=localhost:8080"
+            - "--feature-gates=MachinePool=${EXP_MACHINE_POOL:=false},ClusterResourceSet=${EXP_CLUSTER_RESOURCE_SET:=false},ClusterTopology=${CLUSTER_TOPOLOGY:=false},RuntimeSDK=${EXP_RUNTIME_SDK:=false}"
+          image: controller:latest
+          name: manager
+          env:
+            - name: POD_NAMESPACE
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.namespace
+            - name: POD_NAME
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.name
+            - name: POD_UID
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.uid
+          ports:
+            - containerPort: 9440
+              name: healthz
+              protocol: TCP
+          readinessProbe:
+            httpGet:
+              path: /readyz
+              port: healthz
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: healthz
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - ALL
+            privileged: false
+            runAsUser: 65532
+            runAsGroup: 65532
       terminationGracePeriodSeconds: 10
       serviceAccountName: manager
       tolerations:
         - effect: NoSchedule
           key: node-role.kubernetes.io/master
         - effect: NoSchedule
           key: node-role.kubernetes.io/control-plane
+      securityContext:
+        runAsNonRoot: true
+        seccompProfile:
+          type: RuntimeDefault
diff --git a/controlplane/kubeadm/config/manager/manager.yaml b/controlplane/kubeadm/config/manager/manager.yaml
@@ -16,43 +16,55 @@ spec:
         control-plane: controller-manager
     spec:
       containers:
-      - command:
-        - /manager
-        args:
-        - "--leader-elect"
-        - "--metrics-bind-addr=localhost:8080"
-        - "--feature-gates=ClusterTopology=${CLUSTER_TOPOLOGY:=false},KubeadmBootstrapFormatIgnition=${EXP_KUBEADM_BOOTSTRAP_FORMAT_IGNITION:=false}"
-        image: controller:latest
-        name: manager
-        env:
-        - name: POD_NAMESPACE
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.namespace
-        - name: POD_NAME
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.name
-        - name: POD_UID
-          valueFrom:
-            fieldRef:
-              fieldPath: metadata.uid
-        ports:
-        - containerPort: 9440
-          name: healthz
-          protocol: TCP
-        readinessProbe:
-          httpGet:
-            path: /readyz
-            port: healthz
-        livenessProbe:
-          httpGet:
-            path: /healthz
-            port: healthz
+        - command:
+            - /manager
+          args:
+            - "--leader-elect"
+            - "--metrics-bind-addr=localhost:8080"
+            - "--feature-gates=ClusterTopology=${CLUSTER_TOPOLOGY:=false},KubeadmBootstrapFormatIgnition=${EXP_KUBEADM_BOOTSTRAP_FORMAT_IGNITION:=false}"
+          image: controller:latest
+          name: manager
+          env:
+            - name: POD_NAMESPACE
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.namespace
+            - name: POD_NAME
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.name
+            - name: POD_UID
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.uid
+          ports:
+            - containerPort: 9440
+              name: healthz
+              protocol: TCP
+          readinessProbe:
+            httpGet:
+              path: /readyz
+              port: healthz
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: healthz
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - ALL
+            privileged: false
+            runAsUser: 65532
+            runAsGroup: 65532
       terminationGracePeriodSeconds: 10
       serviceAccountName: manager
       tolerations:
         - effect: NoSchedule
           key: node-role.kubernetes.io/master
         - effect: NoSchedule
           key: node-role.kubernetes.io/control-plane
+      securityContext:
+        runAsNonRoot: true
+        seccompProfile:
+          type: RuntimeDefault
diff --git a/docs/book/src/developer/providers/v1.3-to-v1.4.md b/docs/book/src/developer/providers/v1.3-to-v1.4.md
@@ -5,13 +5,12 @@ maintainers of providers and consumers of our Go API.
 
 ## Minimum Go version
 
-* The Go version used by Cluster API is still Go 1.19.x
+- The Go version used by Cluster API is still Go 1.19.x
 
 ## Dependencies
 
 **Note**: Only the most relevant dependencies are listed, `k8s.io/` and `ginkgo`/`gomega` dependencies in Cluster API are kept in sync with the versions used by `sigs.k8s.io/controller-runtime`.
 
-
 ## Changes by Kind
 
 ### Deprecation
@@ -35,5 +34,8 @@ maintainers of providers and consumers of our Go API.
 ### Other
 
 - `clusterctl upgrade apply` no longer requires a namespace when updating providers. It is now optional and in a future release it will be deprecated. The new syntax is `[namespace/]provider:version`.
+- Cluster API controllers are now using an explicit security context by default.
 
 ### Suggested changes for providers
+
+- Providers should add an explicit security context to their controllers deployment, see [#7831](https://github.com/kubernetes-sigs/cluster-api/pull/7831) for reference.
diff --git a/test/extension/config/default/manager.yaml b/test/extension/config/default/manager.yaml
@@ -14,14 +14,26 @@ spec:
         app: test-extension-manager
     spec:
       containers:
-      - command:
-        - /manager
-        image: controller:latest
-        name: manager
+        - command:
+            - /manager
+          image: controller:latest
+          name: manager
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - ALL
+            privileged: false
+            runAsUser: 65532
+            runAsGroup: 65532
       terminationGracePeriodSeconds: 10
       serviceAccountName: manager
       tolerations:
         - effect: NoSchedule
           key: node-role.kubernetes.io/master
         - effect: NoSchedule
           key: node-role.kubernetes.io/control-plane
+      securityContext:
+        runAsNonRoot: true
+        seccompProfile:
+          type: RuntimeDefault