diff options
| -rw-r--r-- | cloudinit/ec2_utils.py | 58 |
1 files changed, 34 insertions, 24 deletions
diff --git a/cloudinit/ec2_utils.py b/cloudinit/ec2_utils.py index 0c751140..e69d06ff 100644 --- a/cloudinit/ec2_utils.py +++ b/cloudinit/ec2_utils.py @@ -28,23 +28,44 @@ LOG = logging.getLogger(__name__) SKIP_USERDATA_CODES = frozenset([httplib.NOT_FOUND]) -def maybe_json_object(text): - if not text: +class MetadataLeafDecoder(object): + """Decodes a leaf blob into something meaningful.""" + + def _maybe_json_object(self, text): + if not text: + return False + text = text.strip() + if text.startswith("{") and text.endswith("}"): + return True return False - text = text.strip() - if text.startswith("{") and text.endswith("}"): - return True - return False + + def __call__(self, field, blob): + if not blob: + return blob + if self._maybe_json_object(blob): + try: + # Assume it's json, unless it fails parsing... + return json.loads(blob) + except (ValueError, TypeError) as e: + LOG.warn("Field %s looked like a json object, but it was" + " not: %s", field, e) + if blob.find("\n") != -1: + return blob.splitlines() + return blob # See: http://bit.ly/TyoUQs # class MetadataMaterializer(object): - def __init__(self, blob, base_url, caller): + def __init__(self, blob, base_url, caller, leaf_decoder=None): self._blob = blob self._md = None self._base_url = base_url self._caller = caller + if leaf_decoder is None: + self._leaf_decoder = MetadataLeafDecoder() + else: + self._leaf_decoder = leaf_decoder def _parse(self, blob): leaves = {} @@ -90,20 +111,6 @@ class MetadataMaterializer(object): self._md = self._materialize(self._blob, self._base_url) return self._md - def _decode_leaf_blob(self, field, blob): - if not blob: - return blob - if maybe_json_object(blob): - try: - # Assume it's json, unless it fails parsing... - return json.loads(blob) - except (ValueError, TypeError) as e: - LOG.warn("Field %s looked like a json object, but it was" - " not: %s", field, e) - if blob.find("\n") != -1: - return blob.splitlines() - return blob - def _materialize(self, blob, base_url): (leaves, children) = self._parse(blob) child_contents = {} @@ -117,7 +124,7 @@ class MetadataMaterializer(object): for (field, resource) in leaves.items(): leaf_url = url_helper.combine_url(base_url, resource) leaf_blob = str(self._caller(leaf_url)) - leaf_contents[field] = self._decode_leaf_blob(field, leaf_blob) + leaf_contents[field] = self._leaf_decoder(field, leaf_blob) joined = {} joined.update(child_contents) for field in leaf_contents.keys(): @@ -164,7 +171,8 @@ def get_instance_userdata(api_version='latest', def get_instance_metadata(api_version='latest', metadata_address='http://169.254.169.254', - ssl_details=None, timeout=5, retries=5): + ssl_details=None, timeout=5, retries=5, + leaf_decoder=None): md_url = url_helper.combine_url(metadata_address, api_version) # Note, 'meta-data' explicitly has trailing /. # this is required for CloudStack (LP: #1356855) @@ -175,7 +183,9 @@ def get_instance_metadata(api_version='latest', try: response = caller(md_url) - materializer = MetadataMaterializer(str(response), md_url, caller) + materializer = MetadataMaterializer(str(response), + md_url, caller, + leaf_decoder=leaf_decoder) md = materializer.materialize() if not isinstance(md, (dict)): md = {} |