Execution API Priorities

[Josh Cooper]

Jesse contributed a PR so that puppet can specify the priority for processes it starts.[1] This is important when the puppet daemon is running at a lower priority but needs to start process and services running at normal priority.[2]

Adding a `priority` argument to `Puppet::Util::Execute.execute` is easy enough for *nix. However, the `execute` method is an API with different implementations for *nix, Windows and JRuby, and each of those have different ways of expressing priority.

Puppet has a priority setting[3] and it accepts, "‘high’, ‘normal’, ‘low’, or ‘idle’, which are mapped to platform-specific values. The priority can also be specified as an integer value and will be passed as is, e.g. -5."

I'd like to propose that the Execution API follow this convention as well. Comments/Suggestions?

Josh

[1] https://github.com/puppetlabs/puppet/pull/7520
[2] https://tickets.puppetlabs.com/browse/PUP-1353
[3] https://puppet.com/docs/puppet/6.4/configuration.html#priority