This script can be used to feed collectd with cpu and memory usage statistics for running docker containers using the collectd exec plugin.
This script will report the used and cached memory as well as the user and system cpu usage by inspecting the appropriate cgroup stat file for each running container.
This script is intented to be executed by collectd on a host with running docker containers. To use, simply configure the exec plugin in collectd to execute the collectd-docker.sh script. You may need to adjust the script to match your particulars, such as the mount location for cgroup.