(GH-2285) Add support for all proxy schemes, not just https://

This commit fixes GH-2285 by supporting all mod_proxy schemes according to the documentation here:

https://httpd.apache.org/docs/2.4/mod/mod_proxy.html

Type alias `modproxyprotocol` created in order to keep the code neat.

Author: canth1

manifests/balancermember.pp

@@ -40,7 +40,7 @@
 #
 define apache::balancermember (
   String $balancer_cluster,
-  Stdlib::HTTPUrl $url = "http://${$facts['networking']['fqdn']}/",
+  Apache::ModProxyProtocol $url = "http://${$facts['networking']['fqdn']}/",
   Array $options       = [],
 ) {
   concat::fragment { "BalancerMember ${name}":

spec/type_aliases/modproxy_spec.rb

@@ -0,0 +1,20 @@
+require 'spec_helper'
+
+describe 'Apache::ModProxyProtocol' do
+  [
+    'ajp://www.example.com',
+    'fcgi://www.example.com',
+    'ftp://www.example.com',
+    'h2://www.example.com',
+    'h2c://www.example.com',
+    'http://www.example.com',
+    'https://www.example.com',
+    'scgi://www.example.com',
+    'uwsgi://www.example.com',
+    'ws://www.example.com',
+    'wss://www.example.com',
+    'unix:/path/to/unix.socket',
+  ].each do |allowed_value|
+    it { is_expected.to allow_value(allowed_value) }
+  end
+end

types/modproxyprotocol.pp

@@ -0,0 +1,3 @@
+# @summary Supported protocols / schemes by mod_proxy
+# @see https://httpd.apache.org/docs/2.4/mod/mod_proxy.html
+type Apache::ModProxyProtocol = Pattern[/(\A(ajp|fcgi|ftp|h2c?|https?|scgi|uwsgi|wss?):\/\/.+\z)/, /(\Aunix:\/([^\n\/\0]+\/*)*\z)/]