Fix stack trace if vendordata_raw contained an array (#837)

The implementation in existing datasources means that vendordata_raw is
not "raw" as it ideally would be. Instead, actual values may include
bytes, string or list.  If the value was a list, then the attempt to
persist that data to a file in '_store_rawdata' would raise a
TypeError.

The change is to encode with util.json_dumps (which is safe for
binary data) before writing.

1 files changed, 14 insertions, 4 deletions

diff --git a/cloudinit/stages.py b/cloudinit/stages.py
index 3ef4491c..5bacc85d 100644
--- a/cloudinit/stages.py
+++ b/cloudinit/stages.py
@@ -364,12 +364,12 @@ class Init(object):
                             'userdata')
         self._store_processeddata(self.datasource.get_userdata(),
                                   'userdata')
-        self._store_rawdata(self.datasource.get_vendordata_raw(),
-                            'vendordata')
+        self._store_raw_vendordata(self.datasource.get_vendordata_raw(),
+                                   'vendordata')
         self._store_processeddata(self.datasource.get_vendordata(),
                                   'vendordata')
-        self._store_rawdata(self.datasource.get_vendordata2_raw(),
-                            'vendordata2')
+        self._store_raw_vendordata(self.datasource.get_vendordata2_raw(),
+                                   'vendordata2')
         self._store_processeddata(self.datasource.get_vendordata2(),
                                   'vendordata2')
 
@@ -397,6 +397,16 @@ class Init(object):
             data = b''
         util.write_file(self._get_ipath('%s_raw' % datasource), data, 0o600)
 
+    def _store_raw_vendordata(self, data, datasource):
+        # Only these data types
+        if data is not None and type(data) not in [bytes, str, list]:
+            raise TypeError("vendordata_raw is unsupported type '%s'" %
+                            str(type(data)))
+        # This data may be a list, convert it to a string if so
+        if isinstance(data, list):
+            data = util.json_dumps(data)
+        self._store_rawdata(data, datasource)
+
     def _store_processeddata(self, processed_data, datasource):
         # processed is a Mime message, so write as string.
         if processed_data is None: