kata-containers/install/docker/debian-docker-install.md

Install Docker for Kata Containers on Debian

Note:

• This guide assumes you have already installed the Kata Containers packages.
• this guide allows for installation with systemd or sysVinit init systems

1. Install Docker with the following commands:

   Notes:

   • This step is only required if Docker is not installed on the system.
   • Newer versions of Docker have removed devicemapper support so the following commands install the latest version, which includes devicemapper support.
   • To remove the lock on the docker package to allow it to be updated:

     $ sudo apt-mark unhold docker-ce
     

   $ sudo apt-get -y install apt-transport-https ca-certificates curl gnupg2 software-properties-common  
   $ curl -fsSL https://download.docker.com/linux/$(. /etc/os-release; echo "$ID")/gpg | sudo apt-key add -
   $ sudo add-apt-repository "deb https://download.docker.com/linux/$(. /etc/os-release; echo "$ID") $(lsb_release -cs) stable"
   $ sudo apt-get update
   $ sudo -E apt-get -y install --allow-downgrades docker-ce='18.06.2~ce~3-0~debian'
   $ sudo apt-mark hold docker-ce
   

   For more information on installing Docker please refer to the Docker Guide.

2. Configure Docker to use Kata Containers by default with ONE of the following methods:

a. sysVinit

- with sysVinit,  docker config is stored in `/etc/default/docker`, edit the options similar to the following: 
   
```
$ sudo sh -c "echo '# specify docker runtime for kata-containers
DOCKER_OPTS=\"-D --add-runtime kata-runtime=/usr/bin/kata-runtime --default-runtime=kata-runtime\"' >> /etc/default/docker"
```

b. systemd

```bash
$ sudo mkdir -p /etc/systemd/system/docker.service.d/
$ cat <<EOF | sudo tee /etc/systemd/system/docker.service.d/kata-containers.conf
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -D --add-runtime kata-runtime=/usr/bin/kata-runtime --default-runtime=kata-runtime
EOF
```

c. systemd Docker daemon.json

Add the following definitions to `/etc/docker/daemon.json`:

```bash
$ sudo sh -c "echo '{
  \"default-runtime\": \"kata-runtime\",
  \"runtimes\": {
    \"kata-runtime\": {
      \"path\": \"/usr/bin/kata-runtime\"
    }
  }
}' >> /etc/docker/daemon.json"
```

3. Restart the Docker systemd service with one of the following (depending on init choice):

   a. sysVinit

   $ sudo /etc/init.d/docker stop
   $ sudo /etc/init.d/docker start
   

   to watch for errors:

   tail -f /var/log/docker.log
   

   b. systemd

   $ sudo systemctl daemon-reload
   $ sudo systemctl restart docker
   

4. Run Kata Containers

   You are now ready to run Kata Containers:

   $ sudo docker run busybox uname -a
   

   The previous command shows details of the kernel version running inside the container, which is different to the host kernel version.