(#10802) add new function get_module_path

This commit adds a new function called get_module_path.

get_module_path returns the absolute path of a specified module. The
code and functionality is very similar to how templates and files
are detected inside of modules.

the function has been tested against puppet 2.6.10 and 2.7.x

2 files changed, 59 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/get_module_path.rb b/lib/puppet/parser/functions/get_module_path.rb
new file mode 100644
index 0000000..4d2b50b
--- /dev/null
+++ b/lib/puppet/parser/functions/get_module_path.rb
@@ -0,0 +1,17 @@
+module Puppet::Parser::Functions
+  newfunction(:get_module_path, :type =>:rvalue, :doc => <<-EOT
+    Returns the absolute path of the specified module for the current
+    environment.
+
+    Example:
+      $module_path = get_module_path('stdlib')
+  EOT
+  ) do |args|
+    raise(Puppet::ParseError, "get_module_name(): Wrong number of arguments, expects one") unless args.size == 1
+    if module_path = Puppet::Module.find(args[0], compiler.environment.to_s)
+      module_path.path
+    else
+      raise(Puppet::ParseError, "Could not find module #{args[0]} in environment #{compiler.environment}")
+    end
+  end
+end
diff --git a/spec/unit/puppet/parser/functions/get_module_path_spec.rb b/spec/unit/puppet/parser/functions/get_module_path_spec.rb
new file mode 100644
index 0000000..d8340f4
--- /dev/null
+++ b/spec/unit/puppet/parser/functions/get_module_path_spec.rb
@@ -0,0 +1,42 @@
+#!/usr/bin/env rspec
+require 'puppet'
+require 'fileutils'
+require 'spec_helper'
+describe Puppet::Parser::Functions.function(:get_module_path) do
+  include PuppetSpec::Files
+
+  def get_scope(environment = 'production')
+    scope = Puppet::Parser::Scope.new
+    scope.compiler = Puppet::Parser::Compiler.new(Puppet::Node.new("floppy", :environment => environment))
+    scope
+  end
+  it 'should only allow one argument' do
+    expect { get_scope.function_get_module_path([]) }.should raise_error(Puppet::ParseError, /Wrong number of arguments, expects one/)
+    expect { get_scope.function_get_module_path(['1','2','3']) }.should raise_error(Puppet::ParseError, /Wrong number of arguments, expects one/)
+  end
+  it 'should raise an exception when the module cannot be found' do
+    expect { get_scope.function_get_module_path(['foo']) }.should raise_error(Puppet::ParseError, /Could not find module/)
+  end
+  describe 'when locating a module' do
+    let(:modulepath) { tmpdir('modulepath') }
+    let(:foo_path) { File.join(modulepath, 'foo') }
+    before(:each) { FileUtils.mkdir(foo_path) }
+    it 'should be able to find module paths from the modulepath setting' do
+      Puppet[:modulepath] = modulepath
+      get_scope.function_get_module_path(['foo']).should == foo_path
+    end
+    it 'should be able to find module paths when the modulepath is a list' do
+      Puppet[:modulepath] = modulepath + ":/tmp"
+      get_scope.function_get_module_path(['foo']).should == foo_path
+    end
+    it 'should be able to find module paths from the environment' do
+      conf_file = tmpfile('conffile')
+      File.open(conf_file, 'w') do |fh|
+        fh.write("[dansenvironment]\nmodulepath = #{modulepath}")
+      end
+      Puppet[:config] = conf_file
+      Puppet.parse_config
+      get_scope('dansenvironment').function_get_module_path(['foo']).should ==foo_path
+    end
+  end
+end