(maint) Add support for mod_watchdog

This apache module defines programmatic hooks for other apache modules
to periodically run tasks.  It is a dependency for some apache modules
not yet supported by the puppet module:

  * mod_heartbeat
  * mod_heartmonitor
  * mod_md
  * mod_proxy_hcheck

Author: smortex

manifests/mod/watchdog.pp

@@ -0,0 +1,31 @@
+# @summary
+#   Installs and configures `mod_watchdog`.
+#
+# @param watchdog_interval
+#   Sets the interval at which the watchdog_step hook runs.
+#
+# @see https://httpd.apache.org/docs/current/mod/mod_watchdog.html for additional documentation.
+class apache::mod::watchdog (
+  Optional[Integer] $watchdog_interval = undef,
+) {
+  include apache
+
+  $module_builtin = $facts['os']['family'] in ['Debian']
+
+  unless $module_builtin {
+    apache::mod { 'watchdog':
+    }
+  }
+
+  if $watchdog_interval {
+    file { 'watchdog.conf':
+      ensure  => file,
+      path    => "${apache::mod_dir}/watchdog.conf",
+      mode    => $apache::file_mode,
+      content => "WatchdogInterval ${watchdog_interval}\n",
+      require => Exec["mkdir ${apache::mod_dir}"],
+      before  => File[$apache::mod_dir],
+      notify  => Class['apache::service'],
+    }
+  }
+}

spec/classes/mod/watchdog_spec.rb

@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+describe 'apache::mod::watchdog', type: :class do
+  it_behaves_like 'a mod class, without including apache'
+
+  on_supported_os.each do |os, os_facts|
+    context "On #{os}" do
+      let :facts do
+        os_facts
+      end
+
+      if os_facts[:os]['family'] == 'Debian'
+        it { is_expected.not_to contain_apache__mod('watchdog') }
+      else
+        it { is_expected.to contain_apache__mod('watchdog') }
+      end
+
+      context 'with default configuration' do
+        it { is_expected.not_to contain_file('watchdog.conf') }
+      end
+
+      context 'with custom configuration' do
+        let(:params) do
+          {
+            watchdog_interval: 5,
+          }
+        end
+
+        it { is_expected.to contain_file('watchdog.conf').with_content(%r{^WatchdogInterval 5$}) }
+      end
+    end
+  end
+end