Install haveged from EPEL for CentOS

haveged is only available from EPEL for CentOS.  haveged is quite
baked into various CI bits and it doesn't seem worth adding complexity
to diverge from Ubuntu.  This allows us to switch EPEL repo to default
disabled to prevent us picking up package dependencies from there
during CI.

Change-Id: Idad4d68c1f26070660357e559d09859e4a4db4cd
Depends-On: Ic4c0d9483cda08a38ce49ce9d7fc984dc90a17f9

manifests/params.pp

@@ -34,6 +34,13 @@ class jenkins::params {
       # Don't use ccache; not available on centos without EPEL and we
       # have wheel caches on fedora.
       $ccache_package = undef
+
+      # Need to install haveged from EPEL on CentOS.
+      if ($::operatingsystem == 'CentOS') {
+        $haveged_install_options = ['--enablerepo', 'epel']
+      } else {
+        $haveged_install_options = []
+      }
     }
     'Debian': {
       # common packages
@@ -66,6 +73,7 @@ class jenkins::params {
         $ruby_package = 'ruby1.9.1'
         $ruby_dev_package = 'ruby1.9.1-dev'
       }
+      $haveged_install_options = []
     }
     default: {
       fail("Unsupported osfamily: ${::osfamily} The 'jenkins' module only supports osfamily Debian or RedHat (slaves only).")

manifests/slave.pp

@@ -8,7 +8,6 @@ class jenkins::slave(
   $gerrituser = 'jenkins',
 ) {
 
-  include ::haveged
   include ::pip
   include ::jenkins::params
 
@@ -22,6 +21,10 @@ class jenkins::slave(
     }
   }
 
+  class { '::haveged':
+    haveged_install_options => $::jenkins::params::haveged_install_options,
+  }
+
   anchor { 'jenkins::slave::update-java-alternatives': }
 
   # Packages that all jenkins slaves need