Add assemble module

This adds a module that concatenates (ie. assembles) a file from
fragments in a directory in alphabetical order.  It chains the file
module afterward to fix up ownership and permission.  This also adds
tests for the assemble module with fragments in assemble.d.

test/TestRunner.py

@@ -231,5 +231,28 @@ class TestRunner(unittest.TestCase):
     def test_service(self):
         # TODO: tests for the service module
         pass
+    def test_assemble(self):
+        input = self._get_test_file('assemble.d')
+        metadata = self._get_test_file('metadata.json')
+        output = self._get_stage_file('sample.out')
+        result = self._run('assemble', [
+            "src=%s" % input,
+            "dest=%s" % output,
+            "metadata=%s" % metadata
+        ])
+        assert os.path.exists(output)
+        out = file(output).read()
+        assert out.find("first") != -1
+        assert out.find("second") != -1
+        assert out.find("third") != -1
+        assert result['changed'] == True
+        assert 'md5sum' in result
+        assert 'failed' not in result
+        result = self._run('assemble', [
+            "src=%s" % input,
+            "dest=%s" % output,
+            "metadata=%s" % metadata
+        ])
+        assert result['changed'] == False
 
 

test/assemble.d/00-source.txt

@@ -0,0 +1,2 @@
+# This is the first comment.
+[somegroup]

test/assemble.d/01-source.txt

@@ -0,0 +1,2 @@
+# This is the second comment.
+127.0.0.2

test/assemble.d/02.source.txt

@@ -0,0 +1,4 @@
+# This is the third comment.
+[somegroup:vars]
+foo=bar
+# 無 可 無 非 常 無