Forward SIGTERM to child process

What

We have a .NET app which is wrapped in the codecoverage tool in our local development stack, like this:

exec /app/tools/dotnet-coverage collect --session-id "coverage-session" -f cobertura -o "/tmp/coverage/coverage-$(basename "${DLL_NAME}").xml" -- dotnet "$DLL_NAME" "$@"

Inside this application we have a service which hooks into the IHostApplicationLifetime interface to register an action on ApplicationStopping:

// Register shutdown
_hostApplicationLifetime.ApplicationStopping.Register(OnStopping);

However, when running the app wrapped in codecoverage, our OnStopping doesn't fire. That's because codecoverage itself ends up being PID 1 inside the container, and it doesn't pass the SIGTERM signal on to our own application:

$ ps -aux
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
app            1  0.3  0.3 6180692 218940 ?      Ssl  14:30   0:03 /app/tools/dotnet-coverage collect --session-id coverage-session -f cobertura -o /tmp/coverage/coverage-app.dll.xml -- dotnet /app/app.dll
app           17  0.4  0.3 8401572 242552 ?      Sl   14:30   0:03 dotnet /app/app.dll

Proposed solution

codecoverage should pass on any kill signals it gets to the process that it's wrapping, and wait for the child process to terminate before terminating itself.

Start by locating the codecoverage command entry point and the process-launching path that runs the wrapped dotnet child; no source file or test is named in the issue. Done means the child receives termination signals and the wrapper waits for it to terminate.