Embed additional service/package files

[ChrisRx]

Files, such as the kubelet drop-in file 20-crit.conf, can be embedded and templated so that they can be included in the binary and used on systems that do not install from the deb/rpm package (which includes it). This drop-in is a requirement to ensure that the kubelet dynamic configuration (created here) that crit writes out will be loaded by the kubelet systemd service.

For the kubelet drop-in file, crit could potentially check if the file is present when running crit up and copy it in when:

1. It detects that the kubelet service is installed
2. The drop-in does not already exist

I imagine this will be complicated slightly by differences in linux distros with varying standard locations for systemd service files, so this will have to be taken into account.

It is also possible that crit should be able to install other files related to the service, such as the service unit file itself. Any ideas on files that can be included that will help provide a better user experience are extremely welcome.

Files can be added to the templates/ directory and then will be built-in with the crit binary.