Add augeas() function

1 files changed, 68 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/augeas.rb b/lib/puppet/parser/functions/augeas.rb
new file mode 100644
index 0000000..08026f7
--- /dev/null
+++ b/lib/puppet/parser/functions/augeas.rb
@@ -0,0 +1,68 @@
+#
+# augeas.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:augeas, :type => :rvalue, :doc => <<-EOS
+Modifies a string using Augeas.
+
+*Example:*
+
+    augeas("proc        /proc   proc    nodev,noexec,nosuid     0       0\n", 'Fstab.lns', ['rm ./1/opt[3]'])
+
+Would result in:
+
+    "proc        /proc   proc    nodev,noexec     0       0\n"
+    EOS
+  ) do |arguments|
+    unless Puppet.features.augeas?
+      raise Puppet::ParseError, ('augeas(): this function requires the augeas feature. See http://projects.puppetlabs.com/projects/puppet/wiki/Puppet_Augeas#Pre-requisites for how to activate it.')
+    end
+
+    # Check that 2 arguments have been given ...
+    raise(Puppet::ParseError, 'augeas(): Wrong number of arguments ' +
+      "given (#{arguments.size} for 3)") if arguments.size != 3
+
+    content = arguments[0]
+    lens = arguments[1]
+    changes = arguments[2]
+
+    # Check arguments
+    raise(Puppet::ParseError, 'augeas(): content must be a string') unless content.is_a?(String)
+    raise(Puppet::ParseError, 'augeas(): lens must be a string') unless lens.is_a?(String)
+    raise(Puppet::ParseError, 'augeas(): changes must be an array') unless changes.is_a?(Array)
+
+    require 'augeas'
+    aug = Augeas::open(nil, nil, Augeas::NO_MODL_AUTOLOAD)
+    augeas_version = aug.get('/augeas/version')
+    raise(Puppet::ParseError, 'augeas(): requires Augeas 1.0.0 or greater') unless Puppet::Util::Package.versioncmp(augeas_version, '1.0.0') >= 0
+    raise(Puppet::ParseError, 'augeas(): requires ruby-augeas 0.5.0 or greater') unless aug.methods.include?('text_store')
+
+    result = nil
+    begin
+      aug.set('/input', content)
+      aug.text_store(lens, '/input', '/store')
+      unless aug.match("/augeas/text/store//error").empty?
+          error = aug.get("/augeas/text/store//error/message")
+          raise Puppet::ParseError, "augeas(): Failed to parse string with lens #{lens}: #{error}"
+      end
+
+      # Apply changes
+      aug.context = '/store'
+      changes.each do |c|
+        r = aug.srun(c)
+        raise Puppet::ParseError, "augeas(): Failed to apply change to tree" unless r and r[0] >= 0
+      end
+      unless aug.text_retrieve(lens, '/input', '/store', '/output')
+        error = aug.get("/augeas/text/store//error/message")
+        raise Puppet::ParseError, "augeas(): Failed to apply changes with lens #{lens}: #{error}"
+      end
+      result = aug.get("/output")
+    ensure
+      aug.close
+    end
+    return result
+  end
+end
+
+# vim: set ts=2 sw=2 et :