plugin/java: handle OpenJDK as well (#880)

* plugin/java: handle OpenJDK as well

collectd-java requires:
* `libjvm.so()(64bit)`
* `libjvm.so(SUNWprivate_1.1)(64bit)`

On CentOS/RHEL 6.x/7.x these are provided by OpenJDK. OpenJDK stores the
JVM files in a bit of a different location: `amd64` has been removed
from the path. Thus, ATM the link does not get created properly on such
systems.

Fix this problem by adding two `exec` resources which both will try to
create the needed libjvm symbolic link. They are both smart and check if
that file exists before trying to execute. An assumption is added to the
code that both of the files cannot exist at the same time.

* plugin/java: add missing comma

* plugin/java: refactor into human-readable Exec resources

* spec/plugin_java: fix directory

* plugin/java: specify full paths

* plugin/java: ldconfig requires prior resources

* plugin/java: fix the order of ln arguments

* plugin/java: add missing comma

manifests/plugin/java.pp

@@ -19,13 +19,24 @@
       }
     }
     if $java_home {
-      file { '/usr/lib64/libjvm.so':
-        ensure => 'link',
-        target => "${java_home}/jre/lib/amd64/server/libjvm.so",
+      exec { 'Link libjvm.so on OpenJDK':
+        command => "/usr/bin/ln -s ${java_home}/jre/lib/server/libjvm.so /usr/lib64/libjvm.so",
+        creates => '/usr/lib64/libjvm.so',
+        onlyif  => "/usr/bin/test -e ${java_home}/jre/lib/server/libjvm.so",
+        notify  => Exec['/sbin/ldconfig'],
       }
+
+      exec { 'Link libjvm.so on Oracle':
+        command => "/usr/bin/ln -s ${java_home}/jre/lib/amd64/server/libjvm.so /usr/lib64/libjvm.so",
+        creates => '/usr/lib64/libjvm.so',
+        onlyif  => "/usr/bin/test -e ${java_home}/jre/lib/amd64/server/libjvm.so",
+        notify  => Exec['/sbin/ldconfig'],
+      }
+
       # Reload SO files so libjvm.so can be found
-      -> exec { '/sbin/ldconfig':
-        unless => '/sbin/ldconfig -p |grep libjvm.so >/dev/null 2>&1',
+      exec { '/sbin/ldconfig':
+        unless  => '/sbin/ldconfig -p |grep libjvm.so >/dev/null 2>&1',
+        require => [Exec['Link libjvm.so on OpenJDK'], Exec['Link libjvm.so on Oracle']],
       }
     }
   }

spec/classes/collectd_plugin_java_spec.rb

@@ -119,7 +119,8 @@
       when 'RedHat'
         context 'java_home option is empty' do
           it 'will not contain libjvm' do
-            is_expected.not_to contain_file('/usr/lib64/libjvm.so')
+            is_expected.not_to contain_exec('Link libjvm.so on OpenJDK').with_onlyif('/usr/bin/test -e /bla/jre/lib/server/libjvm.so')
+            is_expected.not_to contain_exec('Link libjvm.so on Oracle').with_onlyif('/usr/bin/test -e /bla/jre/lib/amd64/server/libjvm.so')
             is_expected.not_to contain_exec('/sbin/ldconfig')
           end
         end
@@ -132,7 +133,8 @@
           end
 
           it 'will contain libjvm' do
-            is_expected.to contain_file('/usr/lib64/libjvm.so')
+            is_expected.to contain_exec('Link libjvm.so on OpenJDK').with_onlyif('/usr/bin/test -e /bla/jre/lib/server/libjvm.so')
+            is_expected.to contain_exec('Link libjvm.so on Oracle').with_onlyif('/usr/bin/test -e /bla/jre/lib/amd64/server/libjvm.so')
             is_expected.to contain_exec('/sbin/ldconfig')
           end
         end