[docker-compose] start a subset of services, aka, service "profile"

[AndMaz]

Hi

Recent versions of docker-compose support “profile” attribute that allows to selectively start a subset of services declared in the docker-compose file.
More info here: https://docs.docker.com/compose/profiles/

From the docs (docker-compose.yml fields - Balena Documentation) it seems that balena does not support the “profile”.

My question is: From balena perspective, what’s the cleanest way of conditionally starting a subset of services declared in a docker-compose?

Scenario: Depending on the hardware attached to my RPi I want to start all or some of the services defined in the docker-compose

After some investigation I see that I’m not the only one who want this feature:

Selectively running containers on a device

Hi @craigson , the restart: no will not instantiate the container in “stopped”. That field just means the container won’t be restarted in the case that its PID 1 process exits. So it will always start. You can also probably use restart: on-failure which would only restart the container if your process exited for some failed reason, but if it was exit 0 then it would just stop.

Selective Docker Compose

We’ve got a use case EXTREMELY similar to the following thread where we have one version of our application that runs an integrated app/api with an attached screen and then one that runs with only the api and communicates over TCP/IP. The difference here is that the integrated device with a screen is a Pi 3B+ and the standalone api is run on a Pi Zero W. They will share 2 of 3 services with the same exact code base. That means I’m forced to do two difference applications, which seems like the…

[mpous]

Hello @AndMaz first of all welcome to the balena community and apologizes to reply you so late!

You are right, other members from the community requested this feature lately as well. I want to thank you for collecting these forums messages. I added all of this information internally for this feature request.

First of all, we still do not support the profile attribute as it belongs to docker-compose v3. At the moment we support most of the v2.1-2.2 and working on the v2.4 currently. Internally some people see this interesting but sadly this is not implemented yet.

Some ideas or workarounds that you can use today are:

• comment your services and push different releases (A / B) on balenaCloud and then pin the releases to the devices (tag the image to maintain the image data).
• use an envvar and then exit services if the envvar is set to a specific value.

Let me know if that works!