Upgrade to td-agent v4 on older Puppet installs

The fluentd_gem provider for installing fluentd plugins uses
Puppet's built-in gem provider. Unfortunately, that gem provider
on our Puppet version is not compatible with td-agent's new embedded
Ruby since it includes the no-rdoc and no-ri flags deprecated and
replaced by the no-document flag. This install function override
replaces the flags and might be removable after a Puppet upgrade.

lib/puppet/provider/package/fluentd-gem.rb

@@ -8,11 +8,20 @@ Puppet::Type.type(:package).provide :fluentd_gem, :parent => :gem do
     not a valid URL, it will be interpreted as the path to a local gem file.  If
     source is not present at all, the gem will be installed from the default gem
     repositories."
-  confine :exists => "/opt/td-agent/embedded/bin/gem"
+  confine :exists => "/opt/td-agent/bin/gem"
 
   has_feature :versionable, :install_options
 
-  commands :gemcmd => "/opt/td-agent/embedded/bin/gem"
+  commands :gemcmd => "/opt/td-agent/bin/gem"
+
+  def install(useversion = true)
+    command = [command(:gemcmd), "install"]
+    command << "--no-document" << resource[:name]
+    output = execute(command)
+
+    # Apparently some stupid gem versions don't exit non-0 on failure
+    self.fail "Could not install: #{output.chomp}" if output.include?("ERROR")
+  end
 
   def uninstall
     command = [command(:gemcmd), "uninstall"]

manifests/params.pp

@@ -19,7 +19,7 @@ class fluentd::params {
   $user_group  = 'td-agent'
   $user_groups = ['adm']
   # repo params
-  $repo_version = 3
+  $repo_version = 4
 
   case $::osfamily {
     'Debian': {