(maint) Add basic acceptance test for mod_md

manifests/mod/md.pp

@@ -89,6 +89,8 @@
 #  certificate.
 #
 # @see https://httpd.apache.org/docs/current/mod/mod_md.html for additional documentation.
+#
+# @note Unsupported platforms: CentOS: 6, 7; Debian: 8, 9; OracleLinux: all; RedHat: 6, 7; Scientific: all; SLES: all; Ubuntu: 14, 16, 18
 class apache::mod::md (
   Optional[String]                                          $md_activation_delay       = undef,
   Optional[Enum['on', 'off']]                               $md_base_server            = undef,

manifests/params.pp

@@ -231,6 +231,7 @@
         default => 'mod_ldap',
       },
       'lookup_identity'       => 'mod_lookup_identity',
+      'md'                    => 'mod_md',
       'pagespeed'             => 'mod-pagespeed-stable',
       # NOTE: The passenger module isn't available on RH/CentOS without
       # providing dependency packages provided by EPEL and passenger

spec/acceptance/mod_md_spec.rb

@@ -0,0 +1,12 @@
+require 'spec_helper_acceptance'
+
+describe 'apache::mod::md', if: mod_supported_on_platform?('apache::mod::md') do
+  pp = <<-MANIFEST
+    class { 'apache' : }
+    class { 'apache::mod::md': }
+  MANIFEST
+
+  it 'succeeds in installing the mod_md module' do
+    apply_manifest(pp, catch_failures: true)
+  end
+end