Current File : //snap/core20/2318/lib/python3/dist-packages/cloudinit/config/cc_update_hostname.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.
"""Update Hostname: Update hostname and fqdn"""
import logging
import os
from textwrap import dedent
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.settings import PER_ALWAYS
MODULE_DESCRIPTION = """\
This module will update the system hostname and fqdn. If ``preserve_hostname``
is set ``true``, then the hostname will not be altered.
.. note::
for instructions on specifying hostname and fqdn, see documentation for
``cc_set_hostname``
"""
distros = ["all"]
meta: MetaSchema = {
"id": "cc_update_hostname",
"name": "Update Hostname",
"title": "Update hostname and fqdn",
"description": MODULE_DESCRIPTION,
"distros": distros,
"examples": [
dedent(
"""\
# By default: when ``preserve_hostname`` is not specified cloud-init
# updates ``/etc/hostname`` per-boot based on the cloud provided
# ``local-hostname`` setting. If you manually change ``/etc/hostname``
# after boot cloud-init will no longer modify it.
#
# This default cloud-init behavior is equivalent to this cloud-config:
preserve_hostname: false
"""
),
dedent(
"""\
# Prevent cloud-init from updating the system hostname.
preserve_hostname: true
"""
),
dedent(
"""\
# Prevent cloud-init from updating ``/etc/hostname``
preserve_hostname: true
"""
),
dedent(
"""\
# Set hostname to "external.fqdn.me" instead of "myhost"
fqdn: external.fqdn.me
hostname: myhost
prefer_fqdn_over_hostname: true
"""
),
dedent(
"""\
# Set hostname to "external" instead of "external.fqdn.me" when
# cloud metadata provides the ``local-hostname``: "external.fqdn.me".
prefer_fqdn_over_hostname: false
"""
),
],
"frequency": PER_ALWAYS,
"activate_by_schema_keys": [],
}
__doc__ = get_meta_doc(meta)
LOG = logging.getLogger(__name__)
def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None:
if util.get_cfg_option_bool(cfg, "preserve_hostname", False):
LOG.debug(
"Configuration option 'preserve_hostname' is set,"
" not updating the hostname in module %s",
name,
)
return
# Set prefer_fqdn_over_hostname value in distro
hostname_fqdn = util.get_cfg_option_bool(
cfg, "prefer_fqdn_over_hostname", None
)
if hostname_fqdn is not None:
cloud.distro.set_option("prefer_fqdn_over_hostname", hostname_fqdn)
# Set create_hostname_file in distro
create_hostname_file = util.get_cfg_option_bool(
cfg, "create_hostname_file", None
)
if create_hostname_file is not None:
cloud.distro.set_option("create_hostname_file", create_hostname_file)
(hostname, fqdn, is_default) = util.get_hostname_fqdn(cfg, cloud)
if is_default and hostname == "localhost":
# https://github.com/systemd/systemd/commit/d39079fcaa05e23540d2b1f0270fa31c22a7e9f1
LOG.debug("Hostname is localhost. Let other services handle this.")
return
try:
prev_fn = os.path.join(cloud.get_cpath("data"), "previous-hostname")
LOG.debug("Updating hostname to %s (%s)", fqdn, hostname)
cloud.distro.update_hostname(hostname, fqdn, prev_fn)
except Exception:
util.logexc(
LOG, "Failed to update the hostname to %s (%s)", fqdn, hostname
)
raise
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