Add the ability to decompress MIME gzip.

Instead of being restricted to only gzip
compressing the overall mime segment or 
individual included segments, allow for
each mime segment to be gzip compressed.

LP: #1203203

1 files changed, 33 insertions, 8 deletions

diff --git a/cloudinit/user_data.py b/cloudinit/user_data.py
index df069ff8..23c31fde 100644
--- a/cloudinit/user_data.py
+++ b/cloudinit/user_data.py
@@ -48,6 +48,18 @@ ARCHIVE_TYPES = ["text/cloud-config-archive"]
 UNDEF_TYPE = "text/plain"
 ARCHIVE_UNDEF_TYPE = "text/cloud-config"
 
+# This seems to hit most of the gzip possible content types.
+DECOMP_TYPES = [
+    'application/gzip',
+    'application/gzip-compressed',
+    'application/gzipped',
+    'application/x-compress',
+    'application/x-compressed',
+    'application/x-gunzip',
+    'application/x-gzip',
+    'application/x-gzip-compressed',
+]
+
 # Msg header used to track attachments
 ATTACHMENT_FIELD = 'Number-Attachments'
 
@@ -67,6 +79,13 @@ class UserDataProcessor(object):
         return accumulating_msg
 
     def _process_msg(self, base_msg, append_msg):
+
+        def replace_header(part, key, value):
+            if key in part:
+                part.replace_header(key, value)
+            else:
+                part[key] = value
+
         for part in base_msg.walk():
             if is_skippable(part):
                 continue
@@ -75,6 +94,18 @@ class UserDataProcessor(object):
             ctype_orig = part.get_content_type()
             payload = part.get_payload(decode=True)
 
+            # When the message states it is of a gzipped content type ensure
+            # that we attempt to decode said payload so that the decompressed
+            # data can be examined (instead of the compressed data).
+            if ctype_orig in DECOMP_TYPES:
+                try:
+                    payload = util.decomp_gzip(payload, quiet=False)
+                    ctype_orig = UNDEF_TYPE
+                    # TODO(harlowja): should we also set the payload to the
+                    # decompressed value??
+                except util.DecompressionError:
+                    pass
+
             if not ctype_orig:
                 ctype_orig = UNDEF_TYPE
 
@@ -85,10 +116,7 @@ class UserDataProcessor(object):
                 ctype = ctype_orig
 
             if ctype != ctype_orig:
-                if CONTENT_TYPE in part:
-                    part.replace_header(CONTENT_TYPE, ctype)
-                else:
-                    part[CONTENT_TYPE] = ctype
+                replace_header(part, CONTENT_TYPE, ctype)
 
             if ctype in INCLUDE_TYPES:
                 self._do_include(payload, append_msg)
@@ -100,10 +128,7 @@ class UserDataProcessor(object):
 
             # Should this be happening, shouldn't
             # the part header be modified and not the base?
-            if CONTENT_TYPE in base_msg:
-                base_msg.replace_header(CONTENT_TYPE, ctype)
-            else:
-                base_msg[CONTENT_TYPE] = ctype
+            replace_header(base_msg, CONTENT_TYPE, ctype)
 
             self._attach_part(append_msg, part)