tests: k8s: container.exec_commands policy tests

Add tests for genpolicy's handling of container.exec_commands. These
are commands allowed by the policy and originating from these input
K8s YAML fields:

- livenessProbe
- readinessProbe
- startupProbe
- lifecycle.postStart
- lifecycle.preStop

Signed-off-by: Dan Mihai <dmihai@microsoft.com>

tests/integration/kubernetes/k8s-policy-pod.bats

@@ -46,12 +46,17 @@ setup() {
 	cp "${pre_generate_pod_yaml}" "${testcase_pre_generate_pod_yaml}"
 }
 
-@test "Successful pod with auto-generated policy" {
+# Common function for several test cases from this bats script.
+wait_for_pod_ready() {
 	kubectl create -f "${correct_configmap_yaml}"
 	kubectl create -f "${correct_pod_yaml}"
 	kubectl wait --for=condition=Ready "--timeout=${timeout}" pod "${pod_name}"
 }
 
+@test "Successful pod with auto-generated policy" {
+	wait_for_pod_ready
+}
+
 @test "Successful pod with auto-generated policy and runtimeClassName filter" {
 	runtime_class_name=$(yq ".spec.runtimeClassName" < "${testcase_pre_generate_pod_yaml}")
 
@@ -192,6 +197,26 @@ test_pod_policy_error() {
 	kubectl wait --for=condition=Ready "--timeout=${timeout}" pod "${pod_name}"
 }
 
+@test "ExecProcessRequest tests" {
+	wait_for_pod_ready
+
+	# Execute commands allowed by the policy.
+	pod_exec_allowed_command "${pod_name}" "echo" "livenessProbe" "test"
+	pod_exec_allowed_command "${pod_name}" "sh" "-c" "ls -l /"
+	pod_exec_allowed_command "${pod_name}" "echo" "startupProbe" "test"
+
+	# This test should fail but it passes because genpolicy joins the exec args from its
+	# input K8s YAML file and from the command being executed, and compares the joined
+	# command lines instead of comparing each argument.
+	pod_exec_allowed_command "${pod_name}" "echo" "livenessProbe test"
+
+	# Try to execute commands disallowed by the policy.
+	pod_exec_blocked_command "${pod_name}" "echo" "livenessProbe" "test2"
+	pod_exec_blocked_command "${pod_name}" "echo" "livenessProbe" "test" "yes"
+	pod_exec_blocked_command "${pod_name}" "echo" "livenessProbe" "test foo"
+	pod_exec_blocked_command "${pod_name}" "echo" "hello"
+}
+
 teardown() {
 	auto_generate_policy_enabled || skip "Auto-generated policy tests are disabled."
 

tests/integration/kubernetes/runtimeclass_workloads/k8s-policy-pod.yaml

@@ -28,6 +28,27 @@ spec:
         runAsUser: 1000
         seccompProfile:
           type: RuntimeDefault
+      livenessProbe:
+        exec:
+          command:
+            - echo
+            - livenessProbe
+            - test
+        failureThreshold: 1
+        periodSeconds: 5
+        timeoutSeconds: 10
+      readinessProbe:
+        exec:
+          command:
+            - "sh"
+            - "-c"
+            - "ls -l /"
+      startupProbe:
+        exec:
+          command:
+            - echo
+            - startupProbe
+            - test
   topologySpreadConstraints:
     - maxSkew: 2
       topologyKey: kubernetes.io/hostname

tests/integration/kubernetes/tests_common.sh

@@ -321,10 +321,39 @@ add_allow_all_policy_to_yaml() {
 
 # Execute "kubectl describe ${pod}" in a loop, until its output contains "${endpoint} is blocked by policy"
 wait_for_blocked_request() {
-	endpoint="$1"
-	pod="$2"
+	local -r endpoint="$1"
+	local -r pod="$2"
 
-	command="kubectl describe pod ${pod} | grep \"${endpoint} is blocked by policy\""
+	local -r command="kubectl describe pod ${pod} | grep \"${endpoint} is blocked by policy\""
 	info "Waiting ${wait_time} seconds for: ${command}"
 	waitForProcess "${wait_time}" "$sleep_time" "${command}" >/dev/null 2>/dev/null
 }
+
+# Execute in a pod a command that is allowed by policy.
+pod_exec_allowed_command() {
+	local -r pod_name="$1"
+	shift
+
+	local -r exec_output=$(kubectl exec "${pod_name}" -- "${@}" 2>&1)
+
+	local -r exec_args=$(printf '"%s",' "${@}")
+	info "Pod ${pod_name}: <${exec_args::-1}>:"
+	info "${exec_output}"
+
+	(echo "${exec_output}" | grep "policy") && die "exec was blocked by policy!"
+	return 0
+}
+
+# Execute in a pod a command that is blocked by policy.
+pod_exec_blocked_command() {
+	local -r pod_name="$1"
+	shift
+
+	local -r exec_output=$(kubectl exec "${pod_name}" -- "${@}" 2>&1)
+
+	local -r exec_args=$(printf '"%s",' "${@}")
+	info "Pod ${pod_name}: <${exec_args::-1}>:"
+	info "${exec_output}"
+
+	(echo "${exec_output}" | grep "ExecProcessRequest is blocked by policy" > /dev/null) || die "exec was not blocked by policy!"
+}