Handle if the socket exists when a service tries to start tkey-ssh-agent

[dehanj]

Today tkey-ssh-agent creates a unix socket which is used to communicate with the ssh client.

If the tkey-ssh-agent is run in a service, and is not exited gracefully - the socket might not be removed properly. This prevents the service from starting again, since tkey-ssh-agent automatically fails if a socket already exists with the same path. This forces the user to manually remove the existing socket, before the service will start again.

[cobratbq]

The title hints at a mitigation rather than tackling the problem in full. (Though the mitigation would work.) See Go docs.

This can be set to ensure that the socket gets removed on close. The problem, however, is caused by the fact that exiting the program with CTRL+C (break, interrupt) does not gracefully tear down the socket in favor of exiting the runtime entirely. You'll need to install a signal handler and act upon receiving SIGINT then close the socket to give it an opportunity to unlink the socket.

[dehanj]

Thanks for the input! Looks promising, seems like this would solve the problem!
Will look it through more in the upcoming weeks.