write_files: fix decompression of content

When provided with gzipped data, an exception would be raised
because of a conversion to string.

This fixes the issue and adds a test for write_files.

LP: #1565638

3 files changed, 118 insertions, 3 deletions

diff --git a/cloudinit/config/cc_write_files.py b/cloudinit/config/cc_write_files.py
index 4b03ea91..351cfc8c 100644
--- a/cloudinit/config/cc_write_files.py
+++ b/cloudinit/config/cc_write_files.py
@@ -92,10 +92,10 @@ def decode_perms(perm, default, log):
 
 
 def extract_contents(contents, extraction_types):
-    result = str(contents)
+    result = contents
     for t in extraction_types:
         if t == 'application/x-gzip':
-            result = util.decomp_gzip(result, quiet=False)
+            result = util.decomp_gzip(result, quiet=False, decode=False)
         elif t == 'application/base64':
             result = base64.b64decode(result)
         elif t == UNKNOWN_ENC:
diff --git a/cloudinit/distros/__init__.py b/cloudinit/distros/__init__.py
index 418421b9..12983c0a 100644
--- a/cloudinit/distros/__init__.py
+++ b/cloudinit/distros/__init__.py
@@ -933,7 +933,10 @@ def set_etc_timezone(tz, tz_file=None, tz_conf="/etc/timezone",
     # This ensures that the correct tz will be used for the system
     if tz_local and tz_file:
         # use a symlink if there exists a symlink or tz_local is not present
-        if os.path.islink(tz_local) or not os.path.exists(tz_local):
+        islink = os.path.islink(tz_local)
+        if islink or not os.path.exists(tz_local):
+            if islink:
+                util.del_file(tz_local)
             os.symlink(tz_file, tz_local)
         else:
             util.copy(tz_file, tz_local)
diff --git a/tests/unittests/test_handler/test_handler_write_files.py b/tests/unittests/test_handler/test_handler_write_files.py
new file mode 100644
index 00000000..f1c7f7b4
--- /dev/null
+++ b/tests/unittests/test_handler/test_handler_write_files.py
@@ -0,0 +1,112 @@
+from cloudinit import util
+from cloudinit import log as logging
+from cloudinit.config.cc_write_files import write_files
+
+from ..helpers import FilesystemMockingTestCase
+
+import base64
+import gzip
+import shutil
+import six
+import tempfile
+
+LOG = logging.getLogger(__name__)
+
+YAML_TEXT = """
+write_files:
+ - encoding: gzip
+   content: !!binary |
+     H4sIAIDb/U8C/1NW1E/KzNMvzuBKTc7IV8hIzcnJVyjPL8pJ4QIA6N+MVxsAAAA=
+   path: /usr/bin/hello
+   permissions: '0755'
+ - content: !!binary |
+     Zm9vYmFyCg==
+   path: /wark
+   permissions: '0755'
+ - content: |
+    hi mom line 1
+    hi mom line 2
+   path: /tmp/message
+"""
+
+YAML_CONTENT_EXPECTED = {
+    '/usr/bin/hello': "#!/bin/sh\necho hello world\n",
+    '/wark': "foobar\n",
+    '/tmp/message': "hi mom line 1\nhi mom line 2\n",
+}
+
+
+class TestWriteFiles(FilesystemMockingTestCase):
+    def setUp(self):
+        super(TestWriteFiles, self).setUp()
+        self.tmp = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, self.tmp)
+
+    def test_simple(self):
+        self.patchUtils(self.tmp)
+        expected = "hello world\n"
+        filename = "/tmp/my.file"
+        write_files(
+            "test_simple", [{"content": expected, "path": filename}], LOG)
+        self.assertEqual(util.load_file(filename), expected)
+
+    def test_yaml_binary(self):
+        self.patchUtils(self.tmp)
+        data = util.load_yaml(YAML_TEXT)
+        write_files("testname", data['write_files'], LOG)
+        for path, content in YAML_CONTENT_EXPECTED.items():
+            self.assertEqual(util.load_file(path), content)
+
+    def test_all_decodings(self):
+        self.patchUtils(self.tmp)
+
+        # build a 'files' array that has a dictionary of encodings
+        # for 'gz', 'gzip', 'gz+base64' ...
+        data = b"foobzr"
+        utf8_valid = b"foobzr"
+        utf8_invalid = b'ab\xaadef'
+        files = []
+        expected = []
+
+        gz_aliases = ('gz', 'gzip')
+        gz_b64_aliases = ('gz+base64', 'gzip+base64', 'gz+b64', 'gzip+b64')
+        b64_aliases = ('base64', 'b64')
+
+        datum = (("utf8", utf8_valid), ("no-utf8", utf8_invalid))
+        for name, data in datum:
+            gz = (_gzip_bytes(data), gz_aliases)
+            gz_b64 = (base64.b64encode(_gzip_bytes(data)), gz_b64_aliases)
+            b64 = (base64.b64encode(data), b64_aliases)
+            for content, aliases in (gz, gz_b64, b64):
+                for enc in aliases:
+                    cur = {'content': content,
+                           'path': '/tmp/file-%s-%s' % (name, enc),
+                           'encoding': enc}
+                    files.append(cur)
+                    expected.append((cur['path'], data))
+
+        write_files("test_decoding", files, LOG)
+
+        for path, content in expected:
+            self.assertEqual(util.load_file(path, decode=False), content)
+
+        # make sure we actually wrote *some* files.
+        flen_expected = (
+            len(gz_aliases + gz_b64_aliases + b64_aliases) * len(datum))
+        self.assertEqual(len(expected), flen_expected)
+
+
+def _gzip_bytes(data):
+    buf = six.BytesIO()
+    fp = None
+    try:
+        fp = gzip.GzipFile(fileobj=buf, mode="wb")
+        fp.write(data)
+        fp.close()
+        return buf.getvalue()
+    finally:
+        if fp:
+            fp.close()
+
+
+# vi: ts=4 expandtab