openstack/charm-rabbitmq-server
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09c507dd21
charm-rabbitmq-server/charmhelpers/contrib/hahelpers/cluster.py
Corey Bryant f5aa13ee02 Add kinetic support and sync charm-helpers 
Add 22.10 run-on base and add kinetic to metadata.yaml.
Sync charm-helpers to pick up kinetic support.

Change-Id: I26aaceb01f16ddb31123a37454a9cf0d61ed384c
2023-01-31 10:12:20 -05:00

449 lines
14 KiB
Python
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# Copyright 2014-2021 Canonical Limited.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Copyright 2012 Canonical Ltd.
#
# Authors:
# James Page <james.page@ubuntu.com>
# Adam Gandelman <adamg@ubuntu.com>
#
"""
Helpers for clustering and determining "cluster leadership" and other
clustering-related helpers.
"""
import functools
import subprocess
import os
import time
from socket import gethostname as get_unit_hostname
from charmhelpers.core.hookenv import (
log,
relation_ids,
related_units as relation_list,
relation_get,
config as config_get,
INFO,
DEBUG,
WARNING,
unit_get,
is_leader as juju_is_leader,
status_set,
)
from charmhelpers.core.host import (
modulo_distribution,
)
from charmhelpers.core.decorators import (
retry_on_exception,
)
from charmhelpers.core.strutils import (
bool_from_string,
)
DC_RESOURCE_NAME = 'DC'
class HAIncompleteConfig(Exception):
pass
class HAIncorrectConfig(Exception):
pass
class CRMResourceNotFound(Exception):
pass
class CRMDCNotFound(Exception):
pass
def is_elected_leader(resource):
"""
Returns True if the charm executing this is the elected cluster leader.
It relies on two mechanisms to determine leadership:
1. If juju is sufficiently new and leadership election is supported,
the is_leader command will be used.
2. If the charm is part of a corosync cluster, call corosync to
determine leadership.
3. If the charm is not part of a corosync cluster, the leader is
determined as being "the alive unit with the lowest unit number". In
other words, the oldest surviving unit.
"""
try:
return juju_is_leader()
except NotImplementedError:
log('Juju leadership election feature not enabled'
', using fallback support',
level=WARNING)
if is_clustered():
if not is_crm_leader(resource):
log('Deferring action to CRM leader.', level=INFO)
return False
else:
peers = peer_units()
if peers and not oldest_peer(peers):
log('Deferring action to oldest service unit.', level=INFO)
return False
return True
def is_clustered():
for r_id in (relation_ids('ha') or []):
for unit in (relation_list(r_id) or []):
clustered = relation_get('clustered',
rid=r_id,
unit=unit)
if clustered:
return True
return False
def is_crm_dc():
"""
Determine leadership by querying the pacemaker Designated Controller
"""
cmd = ['crm', 'status']
try:
status = subprocess.check_output(
cmd, stderr=subprocess.STDOUT).decode('utf-8')
except subprocess.CalledProcessError as ex:
raise CRMDCNotFound(str(ex))
current_dc = ''
for line in status.split('\n'):
if line.startswith('Current DC'):
# Current DC: juju-lytrusty-machine-2 (168108163)
# - partition with quorum
current_dc = line.split(':')[1].split()[0]
if current_dc == get_unit_hostname():
return True
elif current_dc == 'NONE':
raise CRMDCNotFound('Current DC: NONE')
return False
@retry_on_exception(5, base_delay=2,
exc_type=(CRMResourceNotFound, CRMDCNotFound))
def is_crm_leader(resource, retry=False):
"""
Returns True if the charm calling this is the elected corosync leader,
as returned by calling the external "crm" command.
We allow this operation to be retried to avoid the possibility of getting a
false negative. See LP #1396246 for more info.
"""
if resource == DC_RESOURCE_NAME:
return is_crm_dc()
cmd = ['crm', 'resource', 'show', resource]
try:
status = subprocess.check_output(
cmd, stderr=subprocess.STDOUT).decode('utf-8')
except subprocess.CalledProcessError:
status = None
if status and get_unit_hostname() in status:
return True
if status and "resource %s is NOT running" % (resource) in status:
raise CRMResourceNotFound("CRM resource %s not found" % (resource))
return False
def is_leader(resource):
log("is_leader is deprecated. Please consider using is_crm_leader "
"instead.", level=WARNING)
return is_crm_leader(resource)
def peer_units(peer_relation="cluster"):
peers = []
for r_id in (relation_ids(peer_relation) or []):
for unit in (relation_list(r_id) or []):
peers.append(unit)
return peers
def peer_ips(peer_relation='cluster', addr_key='private-address'):
'''Return a dict of peers and their private-address'''
peers = {}
for r_id in relation_ids(peer_relation):
for unit in relation_list(r_id):
peers[unit] = relation_get(addr_key, rid=r_id, unit=unit)
return peers
def oldest_peer(peers):
"""Determines who the oldest peer is by comparing unit numbers."""
local_unit_no = int(os.getenv('JUJU_UNIT_NAME').split('/')[1])
for peer in peers:
remote_unit_no = int(peer.split('/')[1])
if remote_unit_no < local_unit_no:
return False
return True
def eligible_leader(resource):
log("eligible_leader is deprecated. Please consider using "
"is_elected_leader instead.", level=WARNING)
return is_elected_leader(resource)
def https():
'''
Determines whether enough data has been provided in configuration
or relation data to configure HTTPS
.
returns: boolean
'''
use_https = config_get('use-https')
if use_https and bool_from_string(use_https):
return True
if config_get('ssl_cert') and config_get('ssl_key'):
return True
for r_id in relation_ids('certificates'):
for unit in relation_list(r_id):
ca = relation_get('ca', rid=r_id, unit=unit)
if ca:
return True
for r_id in relation_ids('identity-service'):
for unit in relation_list(r_id):
# TODO - needs fixing for new helper as ssl_cert/key suffixes with CN
rel_state = [
relation_get('https_keystone', rid=r_id, unit=unit),
relation_get('ca_cert', rid=r_id, unit=unit),
]
# NOTE: works around (LP: #1203241)
if (None not in rel_state) and ('' not in rel_state):
return True
return False
def determine_api_port(public_port, singlenode_mode=False):
'''
Determine correct API server listening port based on
existence of HTTPS reverse proxy and/or haproxy.
public_port: int: standard public port for given service
singlenode_mode: boolean: Shuffle ports when only a single unit is present
returns: int: the correct listening port for the API service
'''
i = 0
if singlenode_mode:
i += 1
elif len(peer_units()) > 0 or is_clustered():
i += 1
if https():
i += 1
return public_port - (i * 10)
def determine_apache_port(public_port, singlenode_mode=False):
'''
Description: Determine correct apache listening port based on public IP +
state of the cluster.
public_port: int: standard public port for given service
singlenode_mode: boolean: Shuffle ports when only a single unit is present
returns: int: the correct listening port for the HAProxy service
'''
i = 0
if singlenode_mode:
i += 1
elif len(peer_units()) > 0 or is_clustered():
i += 1
return public_port - (i * 10)
determine_apache_port_single = functools.partial(
determine_apache_port, singlenode_mode=True)
def get_hacluster_config(exclude_keys=None):
'''
Obtains all relevant configuration from charm configuration required
for initiating a relation to hacluster:
ha-bindiface, ha-mcastport, vip, os-internal-hostname,
os-admin-hostname, os-public-hostname, os-access-hostname
param: exclude_keys: list of setting key(s) to be excluded.
returns: dict: A dict containing settings keyed by setting name.
raises: HAIncompleteConfig if settings are missing or incorrect.
'''
settings = ['ha-bindiface', 'ha-mcastport', 'vip', 'os-internal-hostname',
'os-admin-hostname', 'os-public-hostname', 'os-access-hostname']
conf = {}
for setting in settings:
if exclude_keys and setting in exclude_keys:
continue
conf[setting] = config_get(setting)
if not valid_hacluster_config():
raise HAIncorrectConfig('Insufficient or incorrect config data to '
'configure hacluster.')
return conf
def valid_hacluster_config():
'''
Check that either vip or dns-ha is set. If dns-ha then one of os-*-hostname
must be set.
Note: ha-bindiface and ha-macastport both have defaults and will always
be set. We only care that either vip or dns-ha is set.
:returns: boolean: valid config returns true.
raises: HAIncompatibileConfig if settings conflict.
raises: HAIncompleteConfig if settings are missing.
'''
vip = config_get('vip')
dns = config_get('dns-ha')
if not (bool(vip) ^ bool(dns)):
msg = ('HA: Either vip or dns-ha must be set but not both in order to '
'use high availability')
status_set('blocked', msg)
raise HAIncorrectConfig(msg)
# If dns-ha then one of os-*-hostname must be set
if dns:
dns_settings = ['os-internal-hostname', 'os-admin-hostname',
'os-public-hostname', 'os-access-hostname']
# At this point it is unknown if one or all of the possible
# network spaces are in HA. Validate at least one is set which is
# the minimum required.
for setting in dns_settings:
if config_get(setting):
log('DNS HA: At least one hostname is set {}: {}'
''.format(setting, config_get(setting)),
level=DEBUG)
return True
msg = ('DNS HA: At least one os-*-hostname(s) must be set to use '
'DNS HA')
status_set('blocked', msg)
raise HAIncompleteConfig(msg)
log('VIP HA: VIP is set {}'.format(vip), level=DEBUG)
return True
def canonical_url(configs, vip_setting='vip'):
'''
Returns the correct HTTP URL to this host given the state of HTTPS
configuration and hacluster.
:configs : OSTemplateRenderer: A config tempating object to inspect for
a complete https context.
:vip_setting: str: Setting in charm config that specifies
VIP address.
'''
scheme = 'http'
if 'https' in configs.complete_contexts():
scheme = 'https'
if is_clustered():
addr = config_get(vip_setting)
else:
addr = unit_get('private-address')
return '%s://%s' % (scheme, addr)
def distributed_wait(modulo=None, wait=None, operation_name='operation'):
''' Distribute operations by waiting based on modulo_distribution
If modulo and or wait are not set, check config_get for those values.
If config values are not set, default to modulo=3 and wait=30.
:param modulo: int The modulo number creates the group distribution
:param wait: int The constant time wait value
:param operation_name: string Operation name for status message
i.e. 'restart'
:side effect: Calls config_get()
:side effect: Calls log()
:side effect: Calls status_set()
:side effect: Calls time.sleep()
'''
if modulo is None:
modulo = config_get('modulo-nodes') or 3
if wait is None:
wait = config_get('known-wait') or 30
if juju_is_leader():
# The leader should never wait
calculated_wait = 0
else:
# non_zero_wait=True guarantees the non-leader who gets modulo 0
# will still wait
calculated_wait = modulo_distribution(modulo=modulo, wait=wait,
non_zero_wait=True)
msg = "Waiting {} seconds for {} ...".format(calculated_wait,
operation_name)
log(msg, DEBUG)
status_set('maintenance', msg)
time.sleep(calculated_wait)
def get_managed_services_and_ports(services, external_ports,
external_services=None,
port_conv_f=determine_apache_port_single):
"""Get the services and ports managed by this charm.
Return only the services and corresponding ports that are managed by this
charm. This excludes haproxy when there is a relation with hacluster. This
is because this charm passes responsibility for stopping and starting
haproxy to hacluster.
Similarly, if a relation with hacluster exists then the ports returned by
this method correspond to those managed by the apache server rather than
haproxy.
:param services: List of services.
:type services: List[str]
:param external_ports: List of ports managed by external services.
:type external_ports: List[int]
:param external_services: List of services to be removed if ha relation is
present.
:type external_services: List[str]
:param port_conv_f: Function to apply to ports to calculate the ports
managed by services controlled by this charm.
:type port_convert_func: f()
:returns: A tuple containing a list of services first followed by a list of
ports.
:rtype: Tuple[List[str], List[int]]
"""
if external_services is None:
external_services = ['haproxy']
if relation_ids('ha'):
for svc in external_services:
try:
services.remove(svc)
except ValueError:
pass
external_ports = [port_conv_f(p) for p in external_ports]
return services, external_ports
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