From 757b91ed4a4bf91edd4b9d21e7fb5dc1c7ec96c5 Mon Sep 17 00:00:00 2001
From: Sviatoslav Kokurin <funbiscuit@users.noreply.github.com>
Date: Sat, 30 Sep 2023 00:50:30 +0300
Subject: [PATCH] fix: Fix not reading limits when cgroup v2 used (#107)

Docker image was not picking up memory limits when cgroup v2 was used.
This lead to incorrect java heap memory limits that lead to crashes due
to OOMKilled as described in #106.

Add extra check for limits in cgroup v2 file for the image to correctly read
memory limits with both cgroup v1 and cgroup v2.

Resolves #106

---

Signed-off-by: funbiscuit <kokurinsv@gmail.com>
---
 src/main/scripts/start.sh | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/main/scripts/start.sh b/src/main/scripts/start.sh
index a9e97b98..c5fe44eb 100644
--- a/src/main/scripts/start.sh
+++ b/src/main/scripts/start.sh
@@ -309,11 +309,15 @@ fi
 echo $$ > ${ANCHOR_FILE}
 
 if [ "$MEM_LIMIT_MB" = "" ]; then
-	DOCKER_LIM_FILE="/sys/fs/cgroup/memory/memory.limit_in_bytes"
-
-	if [ -e "${DOCKER_LIM_FILE}" ]; then
-		MEM_LIMIT_MB=$(($(cat ${DOCKER_LIM_FILE})/1024/1024))
-		echo "Using process mem limit of ${MEM_LIMIT_MB}MiB from ${DOCKER_LIM_FILE}"
+	CGROUP_V1_LIM_FILE="/sys/fs/cgroup/memory/memory.limit_in_bytes"
+	CGROUP_V2_LIM_FILE="/sys/fs/cgroup/memory.max"
+
+	if [ -e "${CGROUP_V1_LIM_FILE}" ]; then
+		MEM_LIMIT_MB=$(($(cat ${CGROUP_V1_LIM_FILE})/1024/1024))
+		echo "Using process mem limit of ${MEM_LIMIT_MB}MiB from ${CGROUP_V1_LIM_FILE}"
+	elif [ -e "${CGROUP_V2_LIM_FILE}" ]; then
+		MEM_LIMIT_MB=$(($(cat ${CGROUP_V2_LIM_FILE})/1024/1024))
+		echo "Using process mem limit of ${MEM_LIMIT_MB}MiB from ${CGROUP_V2_LIM_FILE}"
 	else
     	MEM_LIMIT_MB="1536"
     	echo "No process mem limit provided or found, defaulting to ${MEM_LIMIT_MB}MiB"