Can't start a fabric at boot time using systemd

There is no documented, supported way to start a bunch of fabric containers at boot time, on a Linux system that only supports systemd for service management.

A typical situation is that a particular Linux server hosts a couple of top-level containers and a bunch of child containers. We want the whole lot to start at boot time, and the whole lot to shut down cleanly when the system shuts down.

We have been able to get around this problem until now, to some extent, by using ugly scripting methods tied to SysV-style init scripts. The good thing about init scripts is that they are "hands off" for the operating system – once the script has been launched it is up to the sysadmin to make everything work. But systemd does not provide this kind of hands-off management – it expects the processes it launches to keep running, and to behave in predictable ways that match its own service model. It is almost impossible to make a fabric installation fit that model.

SysV init scripts have been regarded as legacy features since RHEL 7.0, and as of 7.1 are no longer supported.