Add validate_cmd function

1 files changed, 41 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/validate_cmd.rb b/lib/puppet/parser/functions/validate_cmd.rb
new file mode 100644
index 0000000..e7793c3
--- /dev/null
+++ b/lib/puppet/parser/functions/validate_cmd.rb
@@ -0,0 +1,41 @@
+module Puppet::Parser::Functions
+  newfunction(:validate_cmd, :doc => <<-'ENDHEREDOC') do |args|
+    Perform validation of a string with an external command.
+    The first argument of this function should be a string to
+    test, and the second argument should be a path to a test command
+    taking a file as last argument. If the command, launched against
+    a tempfile containing the passed string, returns a non-null value,
+    compilation will abort with a parse error.
+
+    If a third argument is specified, this will be the error message raised and
+    seen by the user.
+
+    A helpful error message can be returned like this:
+
+    Example:
+
+        validate_cmd($sudoerscontent, '/usr/sbin/visudo -c -f', 'Visudo failed to validate sudoers content')
+
+    ENDHEREDOC
+    if (args.length < 2) or (args.length > 3) then
+      raise Puppet::ParseError, ("validate_cmd(): wrong number of arguments (#{args.length}; must be 2 or 3)")
+    end
+
+    msg = args[2] || "validate_cmd(): failed to validate content with command #{args[1].inspect}"
+
+    content = args[0]
+    checkscript = args[1]
+
+    # Test content in a temporary file
+    tmpfile = Tempfile.new("validate_cmd")
+    tmpfile.write(content)
+    tmpfile.close
+    output = `#{checkscript} #{tmpfile.path} 2>&1 1>/dev/null`
+    r = $?
+    File.delete(tmpfile.path)
+    if output
+      msg += "\nOutput is:\n#{output}"
+    end
+    raise Puppet::ParseError, (msg) unless r == 0
+  end
+end