add nginx_conf accessors for http, servers, and locations

[arlimus]

Resolves #1979

[adamleff]

This is great step in a better direction, @arlimus - thank you!

We need to do some better defense against a user passing in a path that is not readable or doesn't exist lest we try to call methods on nil

Also, I'm curious as to your use of FilterTable in the classes where the table really only has two columns: the key and the contents. While it's elegant for us as developers, it's not elegant for our users that are going to be calling #flatten and #first a lot to get at the actual content (because of the nested arrays). I wonder if there's a better way to handle this.

[adamleff]

Style-wise, the nginx project refers to the program as nginx (all lowercase) or NGINX (all uppercase) but never mixed case. We should probably respect their style and use nginx

[arlimus]

great catch!

[adamleff]

Unless there's a real specific need to do this, I'd rather leave inspect alone as it can prove useful when debugging.

[arlimus]

we should decide if we want the inspec shell to have the pretty-printed resources or their inspect equivalent. for example: nginx_conf right now in the inspec shell will pretty-print to => nginx_conf /etc/nginx/nginx.conf. without this change it would print the entire page full of param debug. I aimed for consistency and for less printing, especially on http, but i also get the argument for the counterpoint (not to forget fewer changes).

[adamleff]

If I initialize nginx_conf with a path to a file that doesn't exist or has no content, params will be nil and you'll try to call #map on NilClass, which will not be fun :)

[arlimus]

good point, also happens when the file has non NGINX content! fixed for now by preventing params from being nil

[adamleff]

I think we can be even more transparent with users, especially when they're debugging / exploring in InSpec shell. Otherwise you get output like this:

inspec> a.http.servers.entries
=> [nginx_conf /Users/aleff/projects/inspec/test/unit/mock/files/nginx.conf, server entry,
 nginx_conf /Users/aleff/projects/inspec/test/unit/mock/files/nginx.conf, server entry]

Can we do something like this instead?

def to_s
  server_name = ''
  unless params['server_name'].flatten.nil?
    server_name = params['server_name'].flatten.first
    server_name += ":#{params['listen'].flatten} unless params['listen'].flatten.nil?
  end
  @parent.parent.to_s + ", #{server_name} server entry"
end

^^^ not perfectly tested, but hopefully you get the gist of what I'm trying to describe.

[arlimus]

Yeah, totally! I wanted to leave it out of this PR to figure out pretty-printing for all 3 new nginx portions in a follow-up PR. Are you ok if we issue this in a follow-up?

[arlimus]

Added both of these to this PR, thank you for the discussion!

[adamleff]

Thanks for the params-nil cleanup :)

[adamleff]

Looks great! Thanks @arlimus - let's get this out there.