From 5fc3f458f9e18e6a8a7b4b0bb15a9fb4be39a6e3 Mon Sep 17 00:00:00 2001
From: David Zuelke <dzuelke@salesforce.com>
Date: Tue, 25 Jun 2024 19:00:31 +0200
Subject: [PATCH] Read container memory limit from cgroup (v1 and v2)

Uses memory.high if available (recommended way of setting a functioning soft limit), then first falls back to memory.max (e.g. from 'docker run -m'), then to memory.low (e.g. from 'docker run --memory-reservation'), and finally to memory.min.

Falls back to direct reading of '/sys/fs/cgroup/memory/memory.limit_in_bytes' for cases where that exists, but no full cgroupfs is mounted (e.g. on Heroku).

Limit enforcement (now to 8 TB) is still in place this way - a Docker v1 value will be read, and run into the limit for unrestricted containers, without hitting the fallback and getting returned.

GUS-W-16052317
---
 lib/environment.sh         |  7 ++++++-
 profile/WEB_CONCURRENCY.sh | 19 +++++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)
 mode change 100644 => 100755 lib/environment.sh

diff --git a/lib/environment.sh b/lib/environment.sh
old mode 100644
new mode 100755
index 2be01abfb..3fd41834a
--- a/lib/environment.sh
+++ b/lib/environment.sh
@@ -86,7 +86,12 @@ write_profile() {
   local bp_dir="$1"
   local build_dir="$2"
   mkdir -p "$build_dir/.profile.d"
-  cp "$bp_dir"/profile/* "$build_dir/.profile.d/"
+  local restore_extglob
+  restore_extglob=$(shopt -p extglob) # will return "shopt -u extglob" (or "-s")
+  cp "$bp_dir"/profile/!(WEB_CONCURRENCY.sh) "$build_dir/.profile.d/"
+  $restore_extglob
+  # concatenate these two together
+  cat "$bp_dir"/etc/cgroups.sh "$bp_dir"/profile/WEB_CONCURRENCY.sh > "$build_dir/.profile.d/WEB_CONCURRENCY.sh"
 }
 
 write_ci_profile() {
diff --git a/profile/WEB_CONCURRENCY.sh b/profile/WEB_CONCURRENCY.sh
index 9e7d7eddf..a541dbd75 100755
--- a/profile/WEB_CONCURRENCY.sh
+++ b/profile/WEB_CONCURRENCY.sh
@@ -31,17 +31,28 @@ log_concurrency() {
 detect_memory() {
   local default=$1
 
-  if [ -e /sys/fs/cgroup/memory/memory.limit_in_bytes ]; then
-    echo $(($(cat /sys/fs/cgroup/memory/memory.limit_in_bytes) / 1048576))
+  local memory_limit
+  memory_limit=$(cgroup_util_read_cgroup_memory_limit_with_fallback) && {
+    echo $(( memory_limit / 1024 / 1024 ))
+    return
+  }
+
+  if (($? == 99)); then
+    dne_memory
   else
     echo "$default"
-  fi
+	fi
+}
+
+dne_memory() {
+	echo "129024"
 }
 
 bound_memory() {
   local detected=$1
   # Memory is bound to the maximum memory of known dyno types: ~126 GB
-  local max_detected_memory=129024
+  local max_detected_memory
+  max_detected_memory=$(dne_memory)
   if (( detected > max_detected_memory )); then
     echo "$max_detected_memory"
   else