Foreman » Installer

add support for flatcar

this PR adds support for flatcar linux on the omaha smart proxy:
https://github.com/theforeman/smart_proxy_omaha/pull/21
We need to add this as an option to the puppet module too.

Move feature and module definitions to f_p::module

This moves the definition of foreman_proxy::feature from
foreman_proxy::settings_file to foreman_proxy::module. It also
simplified it by only passing a $module_enabled variable. This is still
needed because it needs to be in context for template().

Introduce foreman_proxy::plugin::provider

This additional abstraction makes it easier to configure plugins that
are providers when they follow conventions.

Introduce foreman_proxy::plugin::module

This introduces a define for plugins that have a package and a config
file, which is most of them.

Introduce foreman_proxy::provider

This is an abstraction to clearly indicate a provider is being
configured. All built in providers are converted to use this.

Introduce foreman_proxy::module

This define introduced an abstraction for Foreman Proxy modules slightly
more explicit than just the settings_file.

Declare features on SSH and Pulp modules

Use $f_p::plugin::dynflow::external_core

Since 5bde9c79ca05a7d30fd7ec7a85a109220b4950df there is a variable that
explicitly sets the external core. Rather than copying the logic, this
reuses the variable.

Move Ruby package prefix to params

Rather than redefining the package prefix, this introduces the variable
in params.pp.

Drop group parameter on plugins

Setting the group can be useful if other processes need to read the
file, but for foreman-proxy this is not the case.