Developing with Docker

The Dockerfile in this repo builds a Docker image that has current versions of our Rust development tools. This can be the lowest-effort way of setting up a Rust environment for those that don’t have one already.

Development cycle

The developer loop when using Docker is substantially the same as if the tools had been installed directly.

All the source files live in the prql directory on the host. As the source changes, the tools (running in the Docker container) can watch those directories and re-run so results are instantly visible.

When the Docker container exits (say, at the end of the development session), the prql directory on the local machine contains the latest files. Use git to pull or to push the prql repo from the host as normal.

To do all this, build the Docker image and start a container as described in the Installation section.


Once Docker is installed, build the Docker image with the following commands.

Note: It will take some time while Docker pulls in all the necessary developer tools.

cd <top-level-PRQL-directory>
docker build -t prql .

Optional: Install pre-commit on the machine that hosts Docker. It runs several Static Checks to ensure code consistency. You can also configure git to run pre-commit automatically for each commit with the second (one-time) command below.

pre-commit run -a   # Run checks manually
pre-commit install  # (one time) install the git hooks

Finally, start up the Docker container with:

cd <top-level-PRQL-directory>
docker run --rm -it -v $(pwd)/:/src -p 3000:3000 prql
  • There’ll be a root@xxxxxxxxx:/src/# prompt
  • Enter a command to run or test code; for example cargo test
  • Enter exit to stop the container

Running code with Docker

Currently our Docker image only supports running Rust dependencies. (adding hugo & nodejs so that the playground can run would be a welcome contribution.)

Use the docker run... command above, then enter the relevant commands; for example cargo insta test --accept or task run book — more details of the commands are in each component’s file or our Development docs.

Note: The first time you run a component, it may take some time to install additional files. Once they’re built, start up is quick.

Developing the Dockerfile

When making updates to the Dockerfile, we have automated testing that the Dockerfile builds on each merge in test-all.yaml, and automated testing that the confirms all Rust tests pass, in nightly.yaml.

Add a label to the PR pr-test-all or pr-cron to run these tests on a PR.