diff options
Diffstat (limited to 'cloudinit/handlers/cloud_config.py')
| -rw-r--r-- | cloudinit/handlers/cloud_config.py | 136 |
1 files changed, 118 insertions, 18 deletions
diff --git a/cloudinit/handlers/cloud_config.py b/cloudinit/handlers/cloud_config.py index f6d95244..34a73115 100644 --- a/cloudinit/handlers/cloud_config.py +++ b/cloudinit/handlers/cloud_config.py @@ -20,43 +20,143 @@ # You should have received a copy of the GNU General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. +import jsonpatch + from cloudinit import handlers from cloudinit import log as logging +from cloudinit import mergers from cloudinit import util from cloudinit.settings import (PER_ALWAYS) LOG = logging.getLogger(__name__) +MERGE_HEADER = 'Merge-Type' + +# Due to the way the loading of yaml configuration was done previously, +# where previously each cloud config part was appended to a larger yaml +# file and then finally that file was loaded as one big yaml file we need +# to mimic that behavior by altering the default strategy to be replacing +# keys of prior merges. +# +# +# For example +# #file 1 +# a: 3 +# #file 2 +# a: 22 +# #combined file (comments not included) +# a: 3 +# a: 22 +# +# This gets loaded into yaml with final result {'a': 22} +DEF_MERGERS = mergers.string_extract_mergers('dict(replace)+list()+str()') +CLOUD_PREFIX = "#cloud-config" +JSONP_PREFIX = "#cloud-config-jsonp" + +# The file header -> content types this module will handle. +CC_TYPES = { + JSONP_PREFIX: handlers.type_from_starts_with(JSONP_PREFIX), + CLOUD_PREFIX: handlers.type_from_starts_with(CLOUD_PREFIX), +} + class CloudConfigPartHandler(handlers.Handler): def __init__(self, paths, **_kwargs): - handlers.Handler.__init__(self, PER_ALWAYS) - self.cloud_buf = [] + handlers.Handler.__init__(self, PER_ALWAYS, version=3) + self.cloud_buf = None self.cloud_fn = paths.get_ipath("cloud_config") + self.file_names = [] def list_types(self): - return [ - handlers.type_from_starts_with("#cloud-config"), - ] + return list(CC_TYPES.values()) - def _write_cloud_config(self, buf): + def _write_cloud_config(self): if not self.cloud_fn: return - lines = [str(b) for b in buf] - payload = "\n".join(lines) - util.write_file(self.cloud_fn, payload, 0600) + # Capture which files we merged from... + file_lines = [] + if self.file_names: + file_lines.append("# from %s files" % (len(self.file_names))) + for fn in self.file_names: + if not fn: + fn = '?' + file_lines.append("# %s" % (fn)) + file_lines.append("") + if self.cloud_buf is not None: + # Something was actually gathered.... + lines = [ + CLOUD_PREFIX, + '', + ] + lines.extend(file_lines) + lines.append(util.yaml_dumps(self.cloud_buf)) + else: + lines = [] + util.write_file(self.cloud_fn, "\n".join(lines), 0600) + + def _extract_mergers(self, payload, headers): + merge_header_headers = '' + for h in [MERGE_HEADER, 'X-%s' % (MERGE_HEADER)]: + tmp_h = headers.get(h, '') + if tmp_h: + merge_header_headers = tmp_h + break + # Select either the merge-type from the content + # or the merge type from the headers or default to our own set + # if neither exists (or is empty) from the later. + payload_yaml = util.load_yaml(payload) + mergers_yaml = mergers.dict_extract_mergers(payload_yaml) + mergers_header = mergers.string_extract_mergers(merge_header_headers) + all_mergers = [] + all_mergers.extend(mergers_yaml) + all_mergers.extend(mergers_header) + if not all_mergers: + all_mergers = DEF_MERGERS + return (payload_yaml, all_mergers) + + def _merge_patch(self, payload): + # JSON doesn't handle comments in this manner, so ensure that + # if we started with this 'type' that we remove it before + # attempting to load it as json (which the jsonpatch library will + # attempt to do). + payload = payload.lstrip() + payload = util.strip_prefix_suffix(payload, prefix=JSONP_PREFIX) + patch = jsonpatch.JsonPatch.from_string(payload) + LOG.debug("Merging by applying json patch %s", patch) + self.cloud_buf = patch.apply(self.cloud_buf, in_place=False) - def _handle_part(self, _data, ctype, filename, payload, _frequency): + def _merge_part(self, payload, headers): + (payload_yaml, my_mergers) = self._extract_mergers(payload, headers) + LOG.debug("Merging by applying %s", my_mergers) + merger = mergers.construct(my_mergers) + self.cloud_buf = merger.merge(self.cloud_buf, payload_yaml) + + def _reset(self): + self.file_names = [] + self.cloud_buf = None + + def handle_part(self, _data, ctype, filename, # pylint: disable=W0221 + payload, _frequency, headers): # pylint: disable=W0613 if ctype == handlers.CONTENT_START: - self.cloud_buf = [] + self._reset() return if ctype == handlers.CONTENT_END: - self._write_cloud_config(self.cloud_buf) - self.cloud_buf = [] + self._write_cloud_config() + self._reset() return - - filename = util.clean_filename(filename) - if not filename: - filename = '??' - self.cloud_buf.extend(["#%s" % (filename), str(payload)]) + try: + # First time through, merge with an empty dict... + if self.cloud_buf is None or not self.file_names: + self.cloud_buf = {} + if ctype == CC_TYPES[JSONP_PREFIX]: + self._merge_patch(payload) + else: + self._merge_part(payload, headers) + # Ensure filename is ok to store + for i in ("\n", "\r", "\t"): + filename = filename.replace(i, " ") + self.file_names.append(filename.strip()) + except: + util.logexc(LOG, "Failed at merging in cloud config part from %s", + filename) |