Specifying startup arguments for GHA service containers

[joecotton-wk]

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Hello,

I have a workflow that requires custom arguments to be passed to a service container when it starts up. Is this possible in GHA? Specifically, I'm looking for something that corresponds to the docker create [OPTIONS] IMAGE [COMMAND] [ARG...] form of docker create (see the docs).

I'd expect it to look something like this:

services:
  my-test-container:
    image: company/image:tag
    command: binary-name
    arguments: arg1 arg2

which would be equivalent to the following: docker create company/image:tag binary-name arg1 arg2

I've searched the internet, and all I've found are these two Stack Overflow posts:

• https://stackoverflow.com/questions/60849745/how-can-i-run-a-command-in-github-action-service-containers
• https://stackoverflow.com/questions/64031598/creating-a-minios3-container-inside-a-github-actions-yml-file

Both state that this isn't supported, but neither of them cite an official source. I'd like to know:

• Is this possible
• If not:
  • Would this feature be supported sometime in the future?
  • Are there any workarounds other than the ones mentioned in the SO posts linked above? None of those workarounds are desirable.

[dgholz]

It was answered in 2020 on https://github.com/orgs/community/discussions/26688#discussioncomment-3252877 by a engineer was was on the Code to Cloud team at the time, it's not possible.

@chrispat was tagged then, any updates in the meantime if this would be supported in the future?

If I understand it correctly, the workarounds on those SO posts are:

• start the Docker container inside a run step in your job, & get the networking right
• publish a new Docker image based on the original, with your arguments baked in, and use it to run the service in your job

I think those are the only reasonable possibilities.

We're getting around it with the service we want to use, because it can load startup options from a config file. So we:

• bake a VM image with the config file present on disk
• launch our own GitHub runners from that image
• configure our jobs to run on those custom runners
• and use the jobs.*.services.*.volumes option to mount the on-disk config into the service container

Which feels like a bit much.

[jshields]

This seems like a basic option that GitHub Actions needs to provide. As the author of the question stated, the arguments to the docker create command that GHA invokes normally includes "COMMAND" and its own arguments after the image name is specified.
https://docs.docker.com/reference/cli/docker/container/create/

CircleCI allows you to easily specify the command that goes after the image name with the command yaml key as the author expected. Both command and entrypoint can be configured in CircleCI:
https://circleci.com/docs/configuration-reference/#executor-job

It seems quite silly that end users are needing to build their own custom images still after years, because GitHub Actions workflow syntax does not support a command yaml key separate from the options and image that are each their own arguments to the docker create command being run. I guess this might be just an issue with services containers, but I still think this is a basic feature that needs to be provided.

[brbrowning21]

One use case: I want to be able to pass in --default-authentication-plugin=mysql_native_password when I run the mysql:8 service container.