cruise

rusty container manager

See the write-up about the project here.

Running it

This project uses runc so it needs to be run on a Linux machine, which I do in a Vagrant box. If you need to, install Vagrant. My simple configuration is a Vagrantfile with the following contents:

Vagrant.configure("2") do |config|
  config.vm.box = "hashicorp/bionic64"
end

Then, to setup your environment:

# in the directory with your Vagrantfile, setup Vagrant box
vagrant up

# login
vagrant ssh

# install gcc
sudo apt-get update
sudo apt install -y gcc

# install rust, this takes a moment
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# add cargo to your PATH environment variable
source $HOME/.cargo/env

# install docker (used to create container root filesystem)
sudo curl -sSL https://get.docker.com/ | sh

# add the vagrant user to the docker group so we don't need to run docker commands as root
sudo usermod -aG docker vagrant

# logout and back in for the group change to take effect
logout
vagrant ssh

Now to run the container manager daemon in the Vagrant box:

# clone the project
git clone https://github.com/willdeuschle/cruise
cd cruise

# build the project (daemon and client)
cargo build

# start the daemon, specifying its root directory and the path to runc
target/debug/daemon run --lib_root=./tmp/lib_root --runtime_path=/usr/bin/runc

Now let's interact with the running daemon. In a new shell:

# in the directory with your Vagrantfile, login to your Vagrant box
vagrant ssh

# create rootfs for container
cd cruise && mkdir -p tmp/rootfs
docker export $(docker create busybox) | tar -C tmp/rootfs -xf -

# create container
target/debug/client container create my_container --rootfs=tmp/rootfs/ sh -- -c "echo hi; sleep 60; echo bye"

# the last command should output: "created: CONTAINER_ID". let's start CONTAINER_ID
target/debug/client container start CONTAINER_ID

At this point, if we switch back to the daemon shell, we should see hi output over there. If we switch back to our client shell, we can interact some more with our container.

# get container status
target/debug/client container get CONTAINER_ID

For the next minute, we will find that our container is in a Running state. After a minute, in our daemon shell, we will see bye, and our container will transition into a Stopped state. We can now clean up the container:

# delete container
target/debug/client container delete CONTAINER_ID

And if we list our containers, we will see our container no longer exists:

# list containers
target/debug/client container list