Support system core integration (DataDog#359)

* Add support for system_core integration

* fix build for ruby 2.0.0

* Revert "fix build for ruby 2.0.0"

This reverts commit 6099ca9

Author: Dan70402

manifests/integrations/system_core.pp

@@ -0,0 +1,22 @@
+# Class: datadog_agent::integrations::system_core
+#
+# This class will install the necessary configuration for the system_core integration
+#
+# Sample Usage:
+#   include 'datadog_agent::integrations::system_core'
+#
+#
+class datadog_agent::integrations::system_core inherits datadog_agent::params {
+  include datadog_agent
+
+  file {
+    "${datadog_agent::params::conf_dir}/system_core.yaml":
+      ensure  => file,
+      owner   => $datadog_agent::params::dd_user,
+      group   => $datadog_agent::params::dd_group,
+      mode    => '0644',
+      content => template('datadog_agent/agent-conf.d/system_core.yaml.erb'),
+      require => Package[$datadog_agent::params::package_name],
+      notify  => Service[$datadog_agent::params::service_name]
+  }
+}

spec/classes/datadog_agent_integrations_system_core_spec.rb

@@ -0,0 +1,27 @@
+require 'spec_helper'
+
+describe 'datadog_agent::integrations::system_core' do
+  let(:facts) {{
+    operatingsystem: 'Ubuntu',
+  }}
+  let(:conf_dir) { '/etc/dd-agent/conf.d' }
+  let(:dd_user) { 'dd-agent' }
+  let(:dd_group) { 'root' }
+  let(:dd_package) { 'datadog-agent' }
+  let(:dd_service) { 'datadog-agent' }
+  let(:conf_file) { "#{conf_dir}/system_core.yaml" }
+
+  it { should compile.with_all_deps }
+  it { should contain_file(conf_file).with(
+    owner: dd_user,
+    group: dd_group,
+    mode: '0644',
+  )}
+  it { should contain_file(conf_file).that_requires("Package[#{dd_package}]") }
+  it { should contain_file(conf_file).that_notifies("Service[#{dd_service}]") }
+
+  context 'with default parameters' do
+    it { should contain_file(conf_file).with_content(%r{instances:}) }
+    it { should contain_file(conf_file).with_content(%r{  - foo: bar}) }
+  end
+end

templates/agent-conf.d/system_core.yaml.erb

@@ -0,0 +1,10 @@
+#
+# MANAGED BY PUPPET
+#
+
+init_config:
+
+instances:
+  # No configuration is needed for this check.
+  # A single instance needs to be defined with any value.
+  - foo: bar