Docker compose is a tool for running a set of container images — think an application and its database layer — at once and in order. It provides docker compose up — a single command to boot all containers.

One of its benefits is the configuration of what ports to expose to your host operating system, what folders to mount where within the image, what environment variables to set, and how to network the containers together in a yaml configuration file named docker-compose.yml.

But what about the ad-hoc commands you need to run when building an application? Your database migrations, linters, security scanners, and deployment tools?

Keeping tools separate with docker compose run

Another tool in the compose toolbox is docker compose run. You might have used run to open a command line within your application’s docker image to debug something or connecting to a database terminal within a postgres image.

Another useful way to use docker compose run is with small, single-purpose docker images that expose a single command or tool — like aws, terraform, or zap. It’s especially handy to have the versions of these tools and their dependencies locked down across your team.

Adding these tools to your docker-compose.yml file as services allows you to run them directly from docker compose — for example, docker compose run aws s3 sync or docker compose terraform plan — and you’ll always have the correct version installed and running. Great! No more fighting over terraform state versions.

However, now when you run docker compose up, you’ve got a bunch of extra images booting…

Using profiles to limit which containers start

Docker compose has a less-known feature called profiles that allows you to configure groups of services to boot under different conditions. If we group all of our one-off commands into a profile that we never boot, we can get our desired behavior with a slick command line interface.

For your application services, like your app code and database layer, leave no profile configured. They’ll always start when running docker compose up.

For your one-off commands or utilities, add them to a profile (any name will do, since you don’t intend to use it by name). This prevents them from starting when running docker compose up, but still allows you to access the images with docker compose run:

services:
  aws:
    profiles: ["utilities"]

Hope this helps keep your tooling versioned, within reach, and improves your experience using docker compose!