Proxy configuration for runner should not be forwarded to service containers

[larsnystrom-client]

Describe the bug When setting proxy variables for self-hosted runners, those proxy vars are forwarded to service containers. This behavior is impossible to override, as both lowercase and uppercase versions of the proxy variables are added as environment vars to the service container, but setting both http_proxy and HTTP_PROXY in jobs.<job>.services.<service>.env is disallowed (they are considered duplicates).

Generally speaking, I think the proxy configuration for self-hosted runners should not be forwarded to service containers or jobs at all. If jobs/service containers need proxy configuration, that can easily be added in the workflows yaml file. The proxy for the self-hosted runner is only there for the runner to connect to github.com.

To Reproduce Steps to reproduce the behavior:

1. Setup a self-hosted runner and add http_proxy, https_proxy and no_proxy to .env.
2. Start runner.
3. Trigger a workflow with a service container.
4. Notice that the service container is started with -e http_proxy=... etc, even though those variables are not specified in the workflow yaml file.
5. Try in vain to override both http_proxy and HTTP_PROXY for the service container by editing jobs.<job>.services.<service>.env in your workflows yaml.

Expected behavior Proxy configuration for a self-hosted runner should be only for the self-hosted runner. It is needed for the runner to connect to github.com. The proxy configuration should not be assumed to work for jobs and service containers spawned by the runner.

Runner Version and Platform

Version: 2.299.1 OS: Linux

What's not working?

It is impossible to use a self hosted runner behind a proxy, and run service containers without proxy on that runner.

Job Log Output

N/A

Runner and Worker's Diagnostic Logs

N/A