Capture upstart failures to start.

[trestletech]

No description provided.

[aronatkins]

The goal is to prevent respawn on startup failures, correct? Could we use a separate exit code for situations where we are unable to properly initialize the web and admin interfaces? If so, we could configure normal exit with those codes.

A bit of help found here: http://askubuntu.com/questions/62434/why-does-upstart-keep-respawning-my-process

and the upstart docs: http://upstart.ubuntu.com/wiki/Stanzas#normal_exit

[aronatkins]

Maybe what I've proposed is an abuse of normal exit. The exit in your post-stop means a startup failure takes how long to resolve compared to before this PR?

[trestletech]

Looks like a custom exit code form the pgrep and a normal exit didn't change anything. I think the main process (shiny server) would need to exit with a particular code to avoid being respawned.

I think this is as good as we can do right now.