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✏️ Editing: cc_rightscale_userdata.py

# Copyright (C) 2011 Canonical Ltd.
# Copyright (C) 2012, 2013 Hewlett-Packard Development Company, L.P.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Juerg Haefliger <juerg.haefliger@hp.com>
#
# This file is part of cloud-init. See LICENSE file for license information.

import logging
import os
from urllib.parse import parse_qs

from cloudinit import url_helper as uhelp
from cloudinit import util
from cloudinit.cloud import Cloud
from cloudinit.config import Config
from cloudinit.config.schema import MetaSchema, get_meta_doc
from cloudinit.distros import ALL_DISTROS
from cloudinit.settings import PER_INSTANCE

MY_NAME = "cc_rightscale_userdata"
MY_HOOKNAME = "CLOUD_INIT_REMOTE_HOOK"

"""Rightscale Userdata: Support rightscale configuration hooks"""

MODULE_DESCRIPTION = """\
This module adds support for RightScale configuration hooks to cloud-init.
RightScale adds an entry in the format ``CLOUD_INIT_REMOTE_HOOK=http://...`` to
ec2 user-data. This module checks for this line in the raw userdata and
retrieves any scripts linked by the RightScale user data and places them in the
user scripts configuration directory, to be run later by ``cc_scripts_user``.

.. note::
    the ``CLOUD_INIT_REMOTE_HOOK`` config variable is present in the raw ec2
    user data only, not in any cloud-config parts

**Raw user data schema**::

CLOUD_INIT_REMOTE_HOOK=<url>
"""

meta: MetaSchema = {
    "id": "cc_rightscale_userdata",
    "name": "RightScale Userdata",
    "title": "Support rightscale configuration hooks",
    "description": MODULE_DESCRIPTION,
    "distros": [ALL_DISTROS],
    "frequency": PER_INSTANCE,
    "examples": [],
    "activate_by_schema_keys": [],
}

__doc__ = get_meta_doc(meta)
LOG = logging.getLogger(__name__)

#
# The purpose of this script is to allow cloud-init to consume
# rightscale style userdata.  rightscale user data is key-value pairs
# in a url-query-string like format.
#
# for cloud-init support, there will be a key named
# 'CLOUD_INIT_REMOTE_HOOK'.
#
# This cloud-config module will
# - read the blob of data from raw user data, and parse it as key/value
# - for each key that is found, download the content to
#   the local instance/scripts directory and set them executable.
# - the files in that directory will be run by the scripts_user module
#   Therefore, this must run before that.
#
#

def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None:
    get_userdata_raw = getattr(cloud, "get_userdata_raw", None)
    if not get_userdata_raw or not callable(get_userdata_raw):
        LOG.debug("Failed to get raw userdata in module %s", name)
        return

ud = get_userdata_raw()
    try:
        mdict = parse_qs(ud)
        if not mdict or MY_HOOKNAME not in mdict:
            LOG.debug(
                "Skipping module %s, did not find %s in parsed raw userdata",
                name,
                MY_HOOKNAME,
            )
            return
    except Exception:
        util.logexc(
            LOG, "Failed to parse query string %s into a dictionary", ud
        )
        raise

wrote_fns = []
    captured_excps = []

# These will eventually be then ran by the cc_scripts_user
    # TODO(harlowja): maybe this should just be a new user data handler??
    # Instead of a late module that acts like a user data handler?
    scripts_d = cloud.get_ipath_cur("scripts")
    urls = mdict[MY_HOOKNAME]
    for (i, url) in enumerate(urls):
        fname = os.path.join(scripts_d, "rightscale-%02i" % (i))
        try:
            resp = uhelp.readurl(url)
            # Ensure its a valid http response (and something gotten)
            if resp.ok() and resp.contents:
                util.write_file(fname, resp, mode=0o700)
                wrote_fns.append(fname)
        except Exception as e:
            captured_excps.append(e)
            util.logexc(
                LOG, "%s failed to read %s and write %s", MY_NAME, url, fname
            )

if wrote_fns:
        LOG.debug("Wrote out rightscale userdata to %s files", len(wrote_fns))

if len(wrote_fns) != len(urls):
        skipped = len(urls) - len(wrote_fns)
        LOG.debug("%s urls were skipped or failed", skipped)

if captured_excps:
        LOG.warning(
            "%s failed with exceptions, re-raising the last one",
            len(captured_excps),
        )
        raise captured_excps[-1]

MR SKB