Allow to specify pre/post commands from other modules

[baurmatt]

I need a way to specifify pre/post commands from other modules to e.g. be able to trigger database backups/cleanups before/after the backup. My suggestion would be:

• Use the target parameter instead of content for systemd::unit_file["${title}.service"]. This allows us to define the location of the unit file ourself.
• The unit file will be generated by a concat file with the following fragments:
  • Base configuration (order=10)

    [Service]
    User=<%= $user %>
    Group=<%= $group %>
    Type=oneshot
    EnvironmentFile=<%= $config %>

  • Restic Command (order=25)

    <% $commands.each |$command| { -%>
    ExecStart=<%= $command %>
    <% } -%>

• Users can define pre/post commands by creating concat fragments. They can specify the order to get them sorted.
• This keeps the existing API intact and introduces a new hook-in mechanism that works for the described problem.

What do you think?

[baurmatt]

I will provide an implementation