[systemd-devel] Shell expressions in EnvironmentFile

[Jon Stanley]

Since EnvironmentFile in a service isn't sourced by any shell, shell
expressions in it will obviously not work the way that they did in a
SysV style script.

Nor does it seems that the environment gets preserved between
ExecStartPre (where one could run a script that sets environment
variables to be later used in the starting of the service) and
ExecStart, so something like the following won't work:

[Service]
ExecStartPre=/something/that/sets/var
ExecStart=/some/file $var

Is there some way to get dynamically determined data into the
environment such that it can be passed to the daemon at start?