tests/int: don't set/use CGROUP_XXX variables

Helper function init_cgroup_paths sets two sets of cgroup path variables
for cgroup v1 case (below XXX is cgroup controller name, e.g. MEMORY):

1. CGROUP_XXX_BASE_PATH -- path to XXX controller mount point
   (e.g. CGROUP_MEMORY_BASE_PATH=/sys/fs/cgroup/memory);

2. CGROUP_XXX -- path to the particular container XXX controller cgroup
   (e.g. CGROUP_MEMORY=/sys/fs/cgroup/memory/runc-cgroups-integration-test/test-cgroup).

Now, the second set of variables is only used by check_cgroup_value()
(with the sole exception of CGROUP_CPU which is used by
@test "update rt period and runtime").

Remove these variables, as their values are not used much
and are easy to get (as can be seen in the rt test case).

While at it, mark some variables as local.

Signed-off-by: Kir Kolyshkin <[email protected]>

tests/integration/helpers.bash

@@ -149,11 +149,11 @@ function init_cgroup_paths() {
 	else
 		CGROUP_UNIFIED=no
 		CGROUP_SUBSYSTEMS=$(awk '!/^#/ {print $1}' /proc/cgroups)
+		local g base_path
 		for g in ${CGROUP_SUBSYSTEMS}; do
 			base_path=$(gawk '$(NF-2) == "cgroup" && $NF ~ /\<'${g}'\>/ { print $5; exit }' /proc/self/mountinfo)
 			test -z "$base_path" && continue
 			eval CGROUP_${g^^}_BASE_PATH="${base_path}"
-			eval CGROUP_${g^^}="${base_path}${REL_CGROUPS_PATH}"
 		done
 	fi
 }
@@ -167,14 +167,16 @@ function set_cgroups_path() {
 
 # Helper to check a value in cgroups.
 function check_cgroup_value() {
-	source=$1
-	expected=$2
+	local source=$1
+	local expected=$2
+	local cgroup var current
 
 	if [ "x$CGROUP_UNIFIED" = "xyes" ]; then
 		cgroup=$CGROUP_PATH
 	else
-		ctrl=${source%%.*}
-		eval cgroup=\$CGROUP_${ctrl^^}
+		var=${source%%.*}             # controller name (e.g. memory)
+		var=CGROUP_${var^^}_BASE_PATH # variable name (e.g. CGROUP_MEMORY_BASE_PATH)
+		eval cgroup=\$var${REL_CGROUPS_PATH}
 	fi
 
 	current=$(cat $cgroup/$source)

tests/integration/update.bats

@@ -532,23 +532,25 @@ EOF
 	[[ "$ROOTLESS" -ne 0 ]] && requires rootless_cgroup
 	requires cgroups_v1 cgroups_rt no_systemd
 
-	# By default, "${CGROUP_CPU}/cpu.rt_runtime_us" is set to 0, which inhibits
+	local cgroup_cpu="${CGROUP_CPU_BASE_PATH}/${REL_CGROUPS_PATH}"
+
+	# By default, "${cgroup_cpu}/cpu.rt_runtime_us" is set to 0, which inhibits
 	# setting the container's realtimeRuntime. (#2046)
 	#
-	# When $CGROUP_CPU is "/sys/fs/cgroup/cpu,cpuacct/runc-cgroups-integration-test/test-cgroup",
+	# When ${cgroup_cpu} is "/sys/fs/cgroup/cpu,cpuacct/runc-cgroups-integration-test/test-cgroup",
 	# we write the values of /sys/fs/cgroup/cpu,cpuacct/cpu.rt_{period,runtime}_us to:
 	# - sys/fs/cgroup/cpu,cpuacct/runc-cgroups-integration-test/cpu.rt_{period,runtime}_us
 	# - sys/fs/cgroup/cpu,cpuacct/runc-cgroups-integration-test/test-cgroup/cpu.rt_{period,runtime}_us
 	#
 	# Typically period=1000000 runtime=950000 .
 	#
 	# TODO: support systemd
-	mkdir -p "$CGROUP_CPU"
+	mkdir -p "$cgroup_cpu"
 	local root_period root_runtime
 	root_period=$(cat "${CGROUP_CPU_BASE_PATH}/cpu.rt_period_us")
 	root_runtime=$(cat "${CGROUP_CPU_BASE_PATH}/cpu.rt_runtime_us")
 	# the following IFS magic sets dirs=("runc-cgroups-integration-test" "test-cgroup")
-	IFS='/' read -r -a dirs <<<"${CGROUP_CPU//${CGROUP_CPU_BASE_PATH}/}"
+	IFS='/' read -r -a dirs <<<"$REL_CGROUPS_PATH"
 	for ((i = 0; i < ${#dirs[@]}; i++)); do
 		local target="$CGROUP_CPU_BASE_PATH"
 		for ((j = 0; j <= i; j++)); do