Check System and GitLab running processes Max Open Files (ulimit -n)

gitlab-check-open-files.sh

#!/bin/bash
# 
# description: Check System and GitLab running processes Max Open Files (ulimit -n)
# author: Hugo Monteiro (08-05-2025)
#
# System
echo "# System processes limit ---"
echo ""
echo "# System runtime configured Max Open File:"
echo "# allocated: the number of allocated file handles"
echo "# unused: the number of allocated but unused file handles"
echo "# maximum: the maximum number of file handles that the Linux kernel will allocate"
echo ""
echo "allocated      unused     maximum"
cat /proc/sys/fs/file-nr
echo ""
echo ""
# GitLab Processes
echo "# GitLab processes limit ---"
echo ""
echo "Process        User        Limit                     Soft Limit           Hard Limit           Units"
old_max_open_files=""
for user in $(grep '^gitlab' /etc/passwd | cut -d: -f1); do
    for pid in $(ps -u $user -o pid=); do
        max_open_files="$(cat /proc/$pid/limits | grep 'Max open files')"
        if [ "$old_max_open_files" != "max_open_files" ]; then
            old_max_open_files=$max_open_files
            echo -e "$pid         $user       $max_open_files"
        fi
    done
done

echo "Hint: Check if shown open files values are different from what is supposed to be configured under '/etc/sysctl.d' and '/etc/security/limits.d' directories."