A lightweight top like monitor for linux CGroups
A command line / text based Linux Containers monitoring tool that works just like you expect.
In a hurry?
curl -sSl https://raw.githubusercontent.com/yadutaf/ctop/master/cgroup_top.py > /opt/ctop && python /opt/ctop
ctop will help you see what’s going on at the container level. Basically, containers are a logical group of processes isolated using kernel’s cgroups and namespaces. Recently, they have been made popular by Docker and they are also heavily used under the hood by systemd and a load of container tools like lxc, rocket, lmctfy and many others.
Under the hood, ctop will collect all metrics it can from cgroups in realtime and render them to instantly give you an overview of the global system health.
It currently collects metrics related to cpu, memory and block IO usage as well as metadata such as owning user (mostly for systemd based containers), uptime and attempts to guess the container managing technology behind.
When the container technology has been successfully guessed, additional features are exposed like attaching to container (basically, it opens a shell in the container context) and stopping it.
ctop author uses it on production system to quicky detect biggest memory users in low memory situations.
As a monitoring tool, ctop tries to be as dicrete as possible. Nonetheless it still has some expectations. It will need at least Python 2.6 with builtin curses support to run. This is usually found with Debian 6 and newer.
This said, the recommended installation method relies on pip
pip install ctop ctop
If using pip is not an option, which is often the case on production systems, you may also directly grab the self-contained source file directly from github and run it in place. All you’ll need is Python 2.6 (Debian Squeeze):
wget https://raw.githubusercontent.com/yadutaf/ctop/master/cgroup_top.py -O ctop chmod +x ctop ./ctop
Alternatively, if you are a Boot2docker user, you may install a Dockerized version of ctop instead. Please note that this is experimental. You have to have a docker binary inside your container to control / attach to your containers from ctop using this method:
docker pull yadutaf/ctop docker run --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro --volume=/var/run/docker.sock:/var/run/docker.sock -it --rm yadutaf/ctop # Optionally, to resolve uids to usernames, add '--volume /etc/passwd:/etc/passwd:ro'
Monitor local cgroups as used by Docker, LXC, SystemD, ... Usage: ctop [--tree] [--refresh=<seconds>] [--columns=<columns>] [--sort-col=<sort-col>] [--follow=<name>] [--fold=<cgroup>, ...] [--type=<container type>, ...] ctop (-h | --help) Options: --tree Show tree view by default. --fold=<name> Start with <name> cgroup path folded --follow=<name> Follow/highlight cgroup at path. --type=TYPE Only show containers of this type --refresh=<seconds> Refresh display every <seconds> [default: 1]. --columns=<columns> List of optional columns to display. Always includes 'name'. [default: owner,processes,memory,cpu-sys,cpu-user,blkio,cpu-time]. --sort-col=<sort-col> Select column to sort by initially. Can be changed dynamically. [default: cpu-user] -h --help Show this screen.
Additionally, for supported container types (Currently Docker, LXC and OpenVZ):