Avoid potential dependency cycles when used with other modules (DataDog#463)

* Use native pgp key support of the apt module

* apt::source notify apt_update by default

* require Class['apt::update'] as the documentation suggests: https://github.com/puppetlabs/puppetlabs-apt\#adding-new-sources-or-ppas

* Use 'exec' instead of 'ensure_packages' to break a dependencies cycle with some other modules

* Fix spec tests

* Set $key to empty dict if skipping apt key trusting

Author: remicalixte

manifests/ubuntu/agent5.pp

@@ -25,13 +25,17 @@
   Optional[String] $apt_keyserver = undef,
 ) inherits datadog_agent::params{
 
-  ensure_packages(['apt-transport-https'])
+  exec { 'apt-transport-https':
+    command => '/usr/bin/apt-get install -y -q apt-transport-https'
+  }
 
   if !$skip_apt_key_trusting {
-    ::datadog_agent::ubuntu::install_key { [$apt_key]:
-      server => $apt_keyserver,
-      before => Apt::Source['datadog'],
+    $key = {
+      'id' => $apt_key,
+      'server' => $apt_keyserver
     }
+  } else {
+    $key = {}
   }
 
   # This is a hack - I'm not happy about it, but we should rarely
@@ -67,8 +71,9 @@
     location => $location,
     release  => $release,
     repos    => $repos,
-    require  => Package['apt-transport-https'],
-    notify   => [Exec['datadog_apt-get_remove_agent6'],Exec['apt_update']],
+    key      => $key,
+    require  => Exec['apt-transport-https'],
+    notify   => Exec['datadog_apt-get_remove_agent6'],
   }
 
   package { 'datadog-agent-base':
@@ -79,7 +84,7 @@
   package { $datadog_agent::params::package_name:
     ensure  => $agent_version,
     require => [Apt::Source['datadog'],
-                Exec['apt_update']],
+                Class['apt::update']],
   }
 
   if $service_provider {

manifests/ubuntu/agent6.pp

@@ -16,12 +16,17 @@
   Optional[String] $apt_keyserver = undef,
 ) inherits datadog_agent::params {
 
-  ensure_packages(['apt-transport-https'])
+  exec { 'apt-transport-https':
+    command => '/usr/bin/apt-get install -y -q apt-transport-https'
+  }
+
   if !$skip_apt_key_trusting {
-    ::datadog_agent::ubuntu::install_key { [$apt_key]:
-      server => $apt_keyserver,
-      before => Apt::Source['datadog6'],
+    $key = {
+      'id' => $apt_key,
+      'server' => $apt_keyserver
     }
+  } else {
+    $key = {}
   }
 
   apt::source { 'datadog':
@@ -33,8 +38,8 @@
     location => $location,
     release  => $release,
     repos    => $repos,
-    require  => Package['apt-transport-https'],
-    notify   =>  Exec['apt_update'],
+    key      => $key,
+    require  => Exec['apt-transport-https'],
   }
 
   package { 'datadog-agent-base':
@@ -45,7 +50,7 @@
   package { $datadog_agent::params::package_name:
     ensure  => $agent_version,
     require => [Apt::Source['datadog6'],
-                Exec['apt_update']],
+                Class['apt::update']],
   }
 
   if $service_provider {

manifests/ubuntu/install_key.pp

@@ -16,16 +16,16 @@
   end
 
   # it should install the mirror
-  it { should_not contain_datadog_agent__ubuntu__install_key('935F5A436A5A6E8788F0765B226AE980C7A7DA52') }
+  it { should_not contain_apt__key('Add key: 935F5A436A5A6E8788F0765B226AE980C7A7DA52 from Apt::Source datadog') }
   it do
-    should contain_datadog_agent__ubuntu__install_key('A2923DFF56EDA6E76E55E492D3A80E30382E94DE')\
+    should contain_apt__key('Add key: A2923DFF56EDA6E76E55E492D3A80E30382E94DE from Apt::Source datadog')
   end
   context 'overriding keyserver' do
     let(:params) {{
       apt_keyserver: 'hkp://pool.sks-keyservers.net:80',
     }}
     it do
-      should contain_datadog_agent__ubuntu__install_key('A2923DFF56EDA6E76E55E492D3A80E30382E94DE')\
+      should contain_apt__key('Add key: A2923DFF56EDA6E76E55E492D3A80E30382E94DE from Apt::Source datadog')\
         .with_server('hkp://pool.sks-keyservers.net:80')
     end
   end
@@ -38,7 +38,7 @@
 
   # it should install the packages
   it do
-    should contain_package('apt-transport-https')\
+    should contain_exec('apt-transport-https')\
       .that_comes_before('file[/etc/apt/sources.list.d/datadog.list]')
   end
   it do
@@ -91,8 +91,7 @@
   end
 
   # it should install the mirror
-  it { should_not contain_datadog_agent__ubuntu__install_key('935F5A436A5A6E8788F0765B226AE980C7A7DA52') }
-  it { should contain_datadog_agent__ubuntu__install_key('A2923DFF56EDA6E76E55E492D3A80E30382E94DE') }
+  it { should contain_apt__key('Add key: A2923DFF56EDA6E76E55E492D3A80E30382E94DE from Apt::Source datadog6') }
 
   it do
     should contain_file('/etc/apt/sources.list.d/datadog6.list')\
@@ -102,7 +101,7 @@
 
   # it should install the packages
   it do
-    should contain_package('apt-transport-https')\
+    should contain_exec('apt-transport-https')\
       .that_comes_before('file[/etc/apt/sources.list.d/datadog6.list]')
   end
   it do