tests: add integration test for paused-and-updated containers

Such containers should remain paused after the update. This has
historically been true, but this helps ensure that the systemd cgroup
changes (freezing the container during SetUnitProperties) don't break
this behaviour.

Signed-off-by: Aleksa Sarai <asarai@suse.de>

tests/integration/helpers.bash

@@ -126,12 +126,19 @@ function init_cgroup_paths() {
 	if stat -f -c %t /sys/fs/cgroup | grep -qFw 63677270; then
 		CGROUP_UNIFIED=yes
 		# "pseudo" controllers do not appear in /sys/fs/cgroup/cgroup.controllers.
-		# - devices (since kernel 4.15)
-		# - freezer (since kernel 5.2)
-		# Assume these are always available, as it is hard to detect
-		CGROUP_SUBSYSTEMS=$(cat /sys/fs/cgroup/cgroup.controllers; echo devices freezer)
+		# - devices (since kernel 4.15) we must assume to be supported because
+		#   it's quite hard to test.
+		# - freezer (since kernel 5.2) we can auto-detect by looking for the
+		#   "cgroup.freeze" file a *non-root* cgroup.
+		CGROUP_SUBSYSTEMS=$(cat /sys/fs/cgroup/cgroup.controllers; echo devices)
 		CGROUP_BASE_PATH=/sys/fs/cgroup
 		CGROUP_PATH=${CGROUP_BASE_PATH}${REL_CGROUPS_PATH}
+
+		# Find any cgroup.freeze files...
+		if [ -n "$(find "$CGROUP_BASE_PATH" -type f -name "cgroup.freeze" -print -quit)" ]
+		then
+			CGROUP_SUBSYSTEMS+=" freezer"
+		fi
 	else
 		CGROUP_UNIFIED=no
 		CGROUP_SUBSYSTEMS=$(awk '!/^#/ {print $1}' /proc/cgroups)
@@ -200,75 +207,85 @@ function fail() {
 # support it, the test is skipped with a message.
 function requires() {
 	for var in "$@"; do
+		local skip_me
 		case $var in
 		criu)
 			if [ ! -e "$CRIU" ]; then
-				skip "test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		root)
 			if [ "$ROOTLESS" -ne 0 ]; then
-				skip "test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		rootless)
 			if [ "$ROOTLESS" -eq 0 ]; then
-				skip "test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		rootless_idmap)
 			if [[ "$ROOTLESS_FEATURES" != *"idmap"* ]]; then
-				skip "test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		rootless_cgroup)
 			if [[ "$ROOTLESS_FEATURES" != *"cgroup"* ]]; then
-				skip "test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		rootless_no_cgroup)
 			if [[ "$ROOTLESS_FEATURES" == *"cgroup"* ]]; then
-				skip "test requires ${var}"
+				skip_me=1
+			fi
+			;;
+		cgroups_freezer)
+			init_cgroup_paths
+			if [[ "$CGROUP_SUBSYSTEMS" != *"freezer"* ]]; then
+				skip_me=1
 			fi
 			;;
 		cgroups_kmem)
 			init_cgroup_paths
 			if [ ! -e "${CGROUP_MEMORY_BASE_PATH}/memory.kmem.limit_in_bytes" ]; then
-				skip "Test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		cgroups_rt)
 			init_cgroup_paths
 			if [ ! -e "${CGROUP_CPU_BASE_PATH}/cpu.rt_period_us" ]; then
-				skip "Test requires ${var}"
+				skip_me=1
 			fi
 			;;
 		cgroups_v1)
 			init_cgroup_paths
 			if [ "$CGROUP_UNIFIED" != "no" ]; then
-				skip "Test requires cgroups v1"
+				skip_me=1
 			fi
 			;;
 		cgroups_v2)
 			init_cgroup_paths
 			if [ "$CGROUP_UNIFIED" != "yes" ]; then
-				skip "Test requires cgroups v2 (unified)"
+				skip_me=1
 			fi
 			;;
 		systemd)
 			if [ -z "${RUNC_USE_SYSTEMD}" ]; then
-				skip "Test requires systemd"
+				skip_me=1
 			fi
 			;;
 		no_systemd)
 			if [ -n "${RUNC_USE_SYSTEMD}" ]; then
-				skip "Test requires no systemd"
+				skip_me=1
 			fi
 			;;
 		*)
-			fail "BUG: Invalid requires ${var}."
+			fail "BUG: Invalid requires $var."
 			;;
 		esac
+		if [ -n "$skip_me" ]; then
+			skip "test requires $var"
+		fi
 	done
 }
 

tests/integration/pause.bats

@@ -12,8 +12,12 @@ function teardown() {
 }
 
 @test "runc pause and resume" {
-  # XXX: currently cgroups require root containers.
-  requires root
+  if [[ "$ROOTLESS" -ne 0 ]]
+  then
+    requires rootless_cgroup
+    set_cgroups_path "$BUSYBOX_BUNDLE"
+  fi
+  requires cgroups_freezer
 
   # run busybox detached
   runc run -d --console-socket $CONSOLE_SOCKET test_busybox
@@ -37,8 +41,12 @@ function teardown() {
 }
 
 @test "runc pause and resume with nonexist container" {
-  # XXX: currently cgroups require root containers.
-  requires root
+  if [[ "$ROOTLESS" -ne 0 ]]
+  then
+    requires rootless_cgroup
+    set_cgroups_path "$BUSYBOX_BUNDLE"
+  fi
+  requires cgroups_freezer
 
   # run test_busybox detached
   runc run -d --console-socket $CONSOLE_SOCKET test_busybox

tests/integration/update.bats

@@ -355,3 +355,27 @@ EOF
     cat "$CONTAINER_OUTPUT"
     [ -z "$(<"$CONTAINER_OUTPUT")" ]
 }
+
+@test "update paused container" {
+    [[ "$ROOTLESS" -ne 0 ]] && requires rootless_cgroup
+    requires cgroups_freezer
+
+    # Run the container in the background.
+    runc run -d --console-socket "$CONSOLE_SOCKET" test_update
+    [ "$status" -eq 0 ]
+
+    # Pause the container.
+    runc pause test_update
+    [ "$status" -eq 0 ]
+
+    # Trigger an unrelated update.
+    runc update --pids-limit 30 test_update
+    [ "$status" -eq 0 ]
+
+    # The container should still be paused.
+    testcontainer test_update paused
+
+    # Resume the container.
+    runc resume test_update
+    [ "$status" -eq 0 ]
+}