Add pry() function from hunner-pry

Author: hunner

README.markdown

@@ -851,6 +851,20 @@ For example:
 
 *Type*: rvalue.
 
+#### `pry`
+
+This function invokes a pry debugging session in the current scope object. This is useful for debugging manifest code at specific points during a compilation. Should only be used when running `puppet apply` or running a puppet master in the foreground. This requires the `pry` gem to be installed in puppet's rubygems.
+
+*Examples:*
+```puppet
+pry()
+```
+Once in a pry session, some interesting commands:
+
+* Run `catalog` to see the contents currently compiling catalog
+* Run `cd catalog` and `ls` to see catalog methods and instance variables
+* Run `@resource_table` to see the current catalog resource table
+
 #### `assert_private`
 
 Sets the current class or definition as private. Calling the class or definition from outside the current module will fail.

lib/puppet/parser/functions/pry.rb

@@ -0,0 +1,30 @@
+#
+# pry.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:pry, :type => :statement, :doc => <<-EOS
+This function invokes a pry debugging session in the current scope object. This is useful for debugging manifest code at specific points during a compilation.
+
+*Examples:*
+
+    pry()
+    EOS
+  ) do |arguments|
+    begin
+      require 'pry'
+    rescue LoadError
+      raise(Puppet::Error, "pry(): Requires the 'pry' rubygem to use, but it was not found")
+    end
+    #
+    ## Run `catalog` to see the contents currently compiling catalog
+    ## Run `cd catalog` and `ls` to see catalog methods and instance variables
+    ## Run `@resource_table` to see the current catalog resource table
+    #
+    if $stdout.isatty
+      binding.pry # rubocop:disable Lint/Debugger
+    else
+      Puppet.warning 'pry(): cowardly refusing to start the debugger on a daemonized master'
+    end
+  end
+end