Add the ability to configure the cache directory

[lollipopman]

At present the cache directory is hard coded:

def self.setup_default_cache_dir
  windows_dir = windows_data_dir
  @facts_cache_dir = if windows_dir
			 File.join(windows_dir, 'PuppetLabs', 'facter', 'cache', 'cached_facts')
		       else
			 '/opt/puppetlabs/facter/cache/cached_facts'
		       end
end

It would nice to be able to set the cache directory in facter.conf

[joshcooper]

It would nice to be able to set the cache directory in facter.conf

Could you expand on why it would be nice to have?

[scrill]

I think it will be useful in the OSS version that can be installed anywhere:

$ gem install facter
Successfully installed facter-4.9.0
Parsing documentation for facter-4.9.0
Done installing documentation for facter after 1 seconds
1 gem installed

$ which facter
/Users/example/.rbenv/shims/facter

[lollipopman]

It would nice to be able to set the cache directory in facter.conf

Could you expand on why it would be nice to have?

My apologies for not being more descriptive. @scrill hinted at the reason for the original request. We use the facter gem in combination with the puppet gem as part of our testing process. When running tests we get this output:

Warning: Facter: Could not write cache: Permission denied @ dir_s_mkdir - /opt/puppetlabs/facter/cache/cached_facts
Warning: Facter: Could not write cache: Permission denied @ dir_s_mkdir - /opt/puppetlabs/facter/cache/cached_facts

I looked for a way to silence this warning, or move the directory somewhere where the non-root testing user could write. This is when I discovered that the path is hard coded, which was the genesis of this feature request. Thanks!