diff --git a/manifests/init.pp b/manifests/init.pp
index 76afe8df6..b23c98f8f 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -156,6 +156,11 @@
     $real_download_url = pick($download_url,
       "${download_url_base}/download/v${version}/${package_name}-${version}.${os}-${arch}.${download_extension}")
   }
+  $notify_service = $restart_on_change ? {
+    true    => Service['prometheus'],
+    default => undef,
+  }
+
 
   $config_hash_real = assert_type(Hash, deep_merge($config_defaults, $config_hash))
 
diff --git a/spec/classes/prometheus_spec.rb b/spec/classes/prometheus_spec.rb
new file mode 100644
index 000000000..4449025ca
--- /dev/null
+++ b/spec/classes/prometheus_spec.rb
@@ -0,0 +1,197 @@
+require 'spec_helper'
+
+describe 'prometheus' do
+  on_supported_os.each do |os, facts|
+    context "on #{os}" do
+      let(:facts) do
+        facts
+      end
+
+      context 'without parameters' do
+        # prometheus::install
+        it {
+          is_expected.to contain_file('/var/lib/prometheus').with(
+            'ensure' => 'directory',
+            'owner'  => 'prometheus',
+            'group'  => 'prometheus',
+            'mode'   => '0755'
+          )
+        }
+
+        prom_version = '1.5.2'
+        prom_os = facts[:kernel].downcase
+        prom_arch = facts[:architecture] == 'i386' ? '386' : 'amd64'
+
+        it {
+          is_expected.to contain_archive("/tmp/prometheus-#{prom_version}.tar.gz").with(
+            'ensure' => 'present',
+            'extract' => true,
+            'extract_path' => '/opt',
+            'source' => "https://github.com/prometheus/prometheus/releases/download/v#{prom_version}/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}.tar.gz",
+            'checksum_verify' => false,
+            'creates' => "/opt/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}/prometheus",
+            'cleanup' => true
+          ).that_comes_before("File[/opt/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}/prometheus]")
+        }
+
+        it {
+          is_expected.to contain_file("/opt/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}/prometheus").with(
+            'owner'  => 'root',
+            'group'  => 0,
+            'mode'   => '0555'
+          )
+        }
+
+        it {
+          is_expected.to contain_file('/usr/local/bin/prometheus').with(
+            'ensure' => 'link',
+            'target' => "/opt/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}/prometheus"
+          ).that_notifies('Service[prometheus]')
+        }
+
+        it {
+          is_expected.to contain_file('/usr/local/share/prometheus').with(
+            'ensure'  => 'directory',
+            'owner'   => 'prometheus',
+            'group'   => 'prometheus',
+            'mode'    => '0755'
+          )
+        }
+
+        it {
+          is_expected.to contain_file('/usr/local/share/prometheus/consoles').with(
+            'ensure' => 'link',
+            'target' => "/opt/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}/consoles"
+          ).that_notifies('Service[prometheus]')
+        }
+
+        it {
+          is_expected.to contain_file('/usr/local/share/prometheus/console_libraries').with(
+            'ensure' => 'link',
+            'target' => "/opt/prometheus-#{prom_version}.#{prom_os}-#{prom_arch}/console_libraries"
+          ).that_notifies('Service[prometheus]')
+        }
+
+        it {
+          is_expected.to contain_user('prometheus').with(
+            'ensure' => 'present',
+            'system' => true,
+            'groups' => []
+          )
+        }
+
+        it {
+          is_expected.to contain_group('prometheus').with(
+            'ensure' => 'present',
+            'system' => true
+          )
+        }
+
+        # prometheus::config
+        if ['debian-7-x86_64'].include?(os) ||
+           ['centos-6-x86_64', 'redhat-6-x86_64'].include?(os)
+          # init_style = 'debian' or
+          # init_style = 'sysv'
+
+          it {
+            is_expected.to contain_file('/etc/init.d/prometheus').with(
+              'mode'   => '0555',
+              'owner'  => 'root',
+              'group'  => 'root',
+              # 'content' => ...
+            )
+          }
+        elsif ['centos-7-x86_64', 'debian-8-x86_64', 'redhat-7-x86_64', 'ubuntu-16.04-x86_64'].include?(os)
+          # init_style = 'systemd'
+
+          it {
+            is_expected.to contain_file('/etc/systemd/system/prometheus.service').with(
+              'mode'   => '0644',
+              'owner'  => 'root',
+              'group'  => 'root',
+              # 'content' => ...
+            ).that_notifies(['Exec[prometheus-systemd-reload]', 'Class[Prometheus::Run_service]'])
+          }
+
+          it {
+            is_expected.to contain_exec('prometheus-systemd-reload').with(
+              'command'     => 'systemctl daemon-reload',
+              'path'        => ['/usr/bin', '/bin', '/usr/sbin'],
+              'refreshonly' => true
+            )
+          }
+        elsif ['ubuntu-14.04-x86_64'].include?(os)
+          # init_style = 'upstart'
+
+          it {
+            is_expected.to contain_file('/etc/init/prometheus.conf').with(
+              'mode'  => '0444',
+              'owner' => 'root',
+              'group' => 'root',
+              # 'content' => ...
+            )
+          }
+
+          it {
+            is_expected.to contain_file('/etc/init.d/prometheus').with(
+              'ensure' => 'link',
+              'target' => '/lib/init/upstart-job',
+              'owner' => 'root',
+              'group' => 'root',
+              'mode'  => '0755'
+            )
+          }
+        else
+          it {
+            is_expected.to raise_error(Puppet::Error, %r{I don.t know how to create an init script for style})
+          }
+        end
+
+        it {
+          is_expected.to contain_file('/etc/prometheus').with(
+            'ensure'  => 'directory',
+            'owner'   => 'prometheus',
+            'group'   => 'prometheus',
+            'purge'   => true,
+            'recurse' => true
+          )
+        }
+
+        it {
+          is_expected.to contain_file('prometheus.yaml').with(
+            'ensure'  => 'present',
+            'path'    => '/etc/prometheus/prometheus.yaml',
+            'owner'   => 'prometheus',
+            'group'   => 'prometheus',
+            'mode'    => '0660',
+            # 'content' => ...,
+          ).that_notifies('Class[prometheus::service_reload]')
+        }
+
+        # prometheus::alerts
+        it {
+          is_expected.not_to contain_file('/etc/prometheus/alert.rules')
+        }
+
+        # prometheus::run_service
+        it {
+          is_expected.to contain_service('prometheus').with(
+            'ensure'     => 'running',
+            'name'       => 'prometheus',
+            'enable'     => true,
+            'hasrestart' => true
+          )
+        }
+
+        # prometheus::service_reload
+        it {
+          is_expected.to contain_exec('prometheus-reload').with(
+            # 'command'     => 'systemctl reload prometheus',
+            'path'        => ['/usr/bin', '/bin', '/usr/sbin'],
+            'refreshonly' => true
+          )
+        }
+      end
+    end
+  end
+end