Update runner process wrapper
What does this MR do?
Updates the wrapper feature by:
- creating a dedicated API Go module (so that anyone can import it in their projects, like Initial Deployer implementation (gitlab-org/ci-cd/runner-tools/grit!182 - merged) • Tomasz Maczukin • 17.10 does)
- adding support for forceful shutdown
It also fixes parsing of --grpc-listen flag, as the method was added in the original MR, but was not called where it should be
Once the change is merged and we decide that the helpers/runner_wrapper/api package's state is what we want, we should make a tag like helpers/runner_wrapper/api/v0.1.0 to give a proper versioning for the Go module it provides.
We may also consider moving that out from the helpers/ tree - for example storing that at ./wrapper in the project root, to make the package name simpler and less confusing (which the helpers part in the package path may cause).
Why was this MR needed?
To better support external integrations like Initial Deployer implementation (gitlab-org/ci-cd/runner-tools/grit!182 - merged) • Tomasz Maczukin • 17.10