Comment 2 for bug 1803182

In response to my last question, systemd can also manage the signals for us pretty easily:

$ sudo systemctl kill -s USR1 websocketd-osrf

This sends SIGUSR1 to all websocket-osrf processes (not just the parent), putting the back-ends in shutdown mode and leaving the main process alive.

Since we have 2 reasonably simple ways to signal a graceful shutdown, I'm adding a pullrequest for 3.1. Suggestions on how/where best to document this appreciated.