Constrain an applications resources using cgroups

heifer.sh

#!/usr/bin/env bash

## @author  Jay Goldberg
## @email  jaymgoldberg@gmail.com
## @license  Apache 2.0
## @description  constrains an execution to memory and cpu limits using cgroups
## @usage  heifer.sh <cpushares_limit> <mem_limit> <command -args>
## @require  cgcreate
## @require  cgexec
## @require  sudo
#=======================================================================

require=(cgcreate cgexec sudo)

# TODO check that all args present
# TODO check that first 2 args are integers

cpulimit=${1:-768} # 0-1024
memlimit=${2:-4096} # in MB

usage () {
  # TODO HEREDOC
	echo "incorrect usage"
	exit 1
}

# TODO not sure what this is, I wrote it a bit ago
processname="${3? $(usage)}"

shift
shift

u=$(id -un)
g=$(id -gn)

cleanup () {
	# delete the cgroup when script exits
	# this can also be handled by ????
	echo Calling cleanup
	sudo cgdelete memory,cpu:${processname}
}

trap cleanup EXIT

# create cgroup with -a (parameter owner) and -t (tasks file owner)
# if not exists, create
echo Opening sudo to create user-managed cgroup space
sudo cgcreate -a "$u:$g" -t "$u:$g" -g cpu,memory:${processname}

# can also use `cgset`
echo Setting CPU limit...
echo $cpulimit > /sys/fs/cgroup/cpu/${processname}/cpu.shares
echo Setting memory limit...
echo $(($memlimit*1024*1024)) > /sys/fs/cgroup/memory/${processname}/memory.limit_in_bytes

echo Executing the target binary \"${processname}\" using bash
cgexec -g cpu,memory:${processname} --sticky bash -c "$@"

# Bessie the heifer the queen of all cows
# She gave more milk than any law allows
# In the mornin' she gave pasteurized
# At nite she gave homogenized
# Bessie the heifer the queen of all the cows.