Specifically, on startup mount.s3ql must be run (as the desired user as this is a FUSE filesystem), and on shutdown umount.s3ql must be run. In addition, what if we want to fsck.s3ql the filesystem before mounting, or run a Unison synchronization step after startup and before shutdown (all modifications I have made on my own personal upstart).
At first glance I would think I would want to setup a mount unit on systemd, but it appears that the service unit actually fits better with pre and post exec startup commands. (All the man pages are available here.)
And what .target do I depend on to encode the dependency on a network connection?