Puppet Server: Using Ruby Gems
If you have server-side Ruby code in your modules, Puppet Server will run it via JRuby. Generally speaking, this only affects custom parser functions, types, and report processors. For the vast majority of cases this shouldn’t pose any problems because JRuby is highly compatible with vanilla Ruby.
Puppet Server will not load gems from user specified
environment variables because
GEM_PATH and manages
Note: Starting with Puppet Server 2.7.1, you can set custom Java arguments for the
puppetserver gemcommand via the
JAVA_ARGS_CLIenvironment variable, either temporarily on the command line or persistently by adding it to the sysconfig/default file. The
JAVA_ARGS_CLIenvironment variable also controls the arguments used when running the
puppetserver irbsubcommands. See the Server 2.7.1 release notes for details.
Gems with packaged versions of Puppet Server
The value of
GEM_HOME when starting the puppetserver process as root using
a packaged version of
This directory does not exist by default.
Gems when running Puppet Server from source
The value of
GEM_HOME when starting the puppetserver process from the
project root is:
Gems when running Puppet Server spec tests
The value of
GEM_HOME when starting the puppetserver JRuby spec tests
rake spec from the project root is:
This directory is automatically populated by the
rake spec task if it does
not already exist. The directory may be safely removed and it will be
re-populated the next time
rake spec is run in your working copy.
Installing and removing gems
We isolate the Ruby load paths that are accessible to Puppet Server’s
JRuby interpreter, so that it doesn’t load any gems or other code that
you have installed on your system Ruby. If you want Puppet Server to load
additional gems, use the Puppet Server-specific
gem command to install them.
For example, to install the foobar gem, use:
$ sudo puppetserver gem install foobar --no-ri --no-rdoc
puppetserver gem command is simply a wrapper around the usual Ruby
command, so all of the usual arguments and flags should work as expected.
For example, to show your locally installed gems, run:
$ puppetserver gem list
Or, if you’re running from source:
$ lein gem -c ~/.puppetserver/puppetserver.conf list
puppetserver gem command also respects the running user’s
which you can use to configure upstream sources or proxy settings. For example,
.gemrc file containing:
--- :sources: [ 'https://rubygems-mirror.megacorp.com', 'https://rubygems.org' ] http_proxy: "http://proxy.megacorp.com:8888"
This configures the listed
:sources as the
puppetserver gem command’s
upstream sources, and uses the listed
http_proxy, which you can confirm:
$ puppetserver gem environment | grep proxy - "http_proxy" => "http://proxy.megacorp.com:8888"
As with the rest of Puppet Server’s configuration, we recommend managing these
settings with Puppet. You can manage Puppet Server’s gem dependencies with the
package provider shipped in
Note: If you try to load a gem before it’s been installed, the agent run will fail with a
LoadError. If this happens, reload the server after installing the gem to resolve the issue.
Installing gems for use with development:
When running from source, JRuby uses a
relative to the current working directory of the process.
lein gem should be
used to install gems into this location using jruby.
./target/jruby-gems is not used when running the JRuby spec tests, gems
are instead automatically installed into and loaded from
If you need to install a gem for use both during development and testing make
sure the gem is available in both directories.
As an example, the following command installs
pry locally in the project.
Note the use of
-- to pass the following command line arguments to the gem
$ lein gem --config ~/.puppetserver/puppetserver.conf -- install pry \ --no-ri --no-rdoc Fetching: coderay-1.1.0.gem (100%) Successfully installed coderay-1.1.0 Fetching: slop-3.6.0.gem (100%) Successfully installed slop-3.6.0 Fetching: method_source-0.8.2.gem (100%) Successfully installed method_source-0.8.2 Fetching: spoon-0.0.4.gem (100%) Successfully installed spoon-0.0.4 Fetching: pry-0.10.1-java.gem (100%) Successfully installed pry-0.10.1-java 5 gems installed
With the gem installed into the project tree
pry can be invoked from inside
Ruby code. For more detailed information on
Puppet Server: Debugging.
Gems with Native (C) Extensions
If, in your custom parser functions or report processors, you’re using Ruby
gems that require native (C) extensions, you won’t be able to install these gems
under JRuby. In many cases, however, there are drop-in replacements implemented
in Java. For example, the popular Nokogiri gem for
processing XML provides a completely compatible Java implementation that’s
automatically installed if you run
gem install via JRuby or Puppet Server,
so you shouldn’t need to change your code at all.
In other cases, there may be a replacement gem available with a slightly
different name; e.g.,
jdbc-mysql instead of
mysql. The JRuby wiki
C Extension Alternatives
page discusses this issue further.
If you’re using a gem that won’t run on JRuby and you can’t find a suitable replacement, please open a ticket on our Issue Tracker; we’re definitely interested in helping provide solutions if there are common gems that are causing trouble for users!