This article walks you through how to configure images for use with CVMs, as well as how to access images located in private registries.
The following sections show how you can configure your image to include systemd and Docker for use in CVMs.
If your image's OS distribution doesn't link the
systemd init to
you'll need to do this manually in your Dockerfile.
The following snippet shows how you can specify
systemd as the init in your
FROM ubuntu:20.04 RUN apt-get update && apt-get install -y \ build-essential \ systemd # use systemd as the init RUN ln -s /lib/systemd/systemd /sbin/init
When you start up a workspace, Coder checks for the presence of
your image. If it exists, then Coder uses it as the container entrypoint with a
PID of 1.
To add Docker, install the
docker packages into your image. For a seamless
experience, use systemd and register the
docker service so
dockerd runs automatically during initialization.
The following snippet shows how your image can register the
docker services in
its Dockerfile. For a full example, see our
enterprise-base image for a full example.
FROM ubuntu:20.04 RUN apt-get update && apt-get install -y \ build-essential \ git \ bash \ docker.io \ curl \ sudo \ systemd # Enables Docker starting with systemd RUN systemctl enable docker # use systemd as the init RUN ln -s /lib/systemd/systemd /sbin/init # Add docker-compose RUN curl -L "https://github.com/docker/compose/releases/download/2.4.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose \ && chmod +x /usr/local/bin/docker-compose # Add a user `coder` so that you're not developing as the `root` user RUN useradd coder \ --create-home \ --shell=/bin/bash \ --groups=docker \ --uid=1000 \ --user-group && \ echo "coder ALL=(ALL) NOPASSWD:ALL" >>/etc/sudoers.d/nopasswd USER coder
To use CVM workspaces with private images, you must create a registry with authentication credentials. Private images that can be pulled directly by the node will not work with CVMs.
This restriction does not apply if you enable cached CVMs.