pvc/daemon-common/zkhandler.py
Joshua M. Boniface e7b6a3eac1 Implement SR-IOV PF and VF instances
Adds support for the node daemon managing SR-IOV PF and VF instances.

PFs are added to Zookeeper automatically based on the config at startup
during network configuration, and are otherwise completely static. PFs
are automatically removed from Zookeeper, along with all coresponding
VFs, should the PF phy device be removed from the configuration.

VFs are configured based on the (autocreated) VFs of each PF device,
added to Zookeeper, and then a new class instance, SRIOVVFInstance, is
used to watch them for configuration changes. This will enable the
runtime management of VF settings by the API. The set of keys ensures
that both configuration and details of the NIC can be tracked.

Most keys are self-explanatory, especially for PFs and the basic keys
for VFs. The configuration tree is also self-explanatory, being based
entirely on the options available in the `ip link set {dev} vf` command.

Two additional keys are also present: `used` and `used_by`, which will
be able to track the (boolean) state of usage, as well as the VM that
uses a given VIF. Since the VM side implementation will support both
macvtap and direct "hostdev" assignments, this will ensure that this
state can be tracked on both the VF and the VM side.
2021-06-17 01:33:03 -04:00

973 lines
35 KiB
Python

#!/usr/bin/env python3
# zkhandler.py - Secure versioned ZooKeeper updates
# Part of the Parallel Virtual Cluster (PVC) system
#
# Copyright (C) 2018-2021 Joshua M. Boniface <joshua@boniface.me>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
#
###############################################################################
import os
import time
import uuid
import json
import re
from functools import wraps
from kazoo.client import KazooClient, KazooState
from kazoo.exceptions import NoNodeError
#
# Function decorators
#
class ZKConnection(object):
"""
Decorates a function with a Zookeeper connection before and after the main call.
The decorated function must accept the `zkhandler` argument as its first argument, and
then use this to access the connection.
"""
def __init__(self, config):
self.config = config
def __call__(self, function):
if not callable(function):
return
@wraps(function)
def connection(*args, **kwargs):
zkhandler = ZKHandler(self.config)
zkhandler.connect()
schema_version = zkhandler.read('base.schema.version')
if schema_version is None:
schema_version = 0
zkhandler.schema.load(schema_version, quiet=True)
ret = function(zkhandler, *args, **kwargs)
zkhandler.disconnect()
del zkhandler
return ret
return connection
#
# Exceptions
#
class ZKConnectionException(Exception):
"""
A exception when connecting to the cluster
"""
def __init__(self, zkhandler, error=None):
if error is not None:
self.message = "Failed to connect to Zookeeper at {}: {}".format(zkhandler.coordinators(), error)
else:
self.message = "Failed to connect to Zookeeper at {}".format(zkhandler.coordinators())
zkhandler.disconnect()
def __str__(self):
return str(self.message)
#
# Handler class
#
class ZKHandler(object):
def __init__(self, config, logger=None):
"""
Initialize an instance of the ZKHandler class with config
A zk_conn object will be created but not started
A ZKSchema instance will be created
"""
self.encoding = 'utf8'
self.coordinators = config['coordinators']
self.logger = logger
self.zk_conn = KazooClient(hosts=self.coordinators)
self._schema = ZKSchema()
#
# Class meta-functions
#
def coordinators(self):
return str(self.coordinators)
def log(self, message, state=''):
if self.logger is not None:
self.logger.out(message, state)
else:
print(message)
#
# Properties
#
@property
def schema(self):
return self._schema
#
# State/connection management
#
def listener(self, state):
if state == KazooState.CONNECTED:
self.log('Connection to Zookeeper started', state='o')
else:
self.log('Connection to Zookeeper lost', state='w')
while True:
time.sleep(0.5)
_zk_conn = KazooClient(hosts=self.coordinators)
try:
_zk_conn.start()
except Exception:
del _zk_conn
continue
self.zk_conn = _zk_conn
self.zk_conn.add_listener(self.listener)
break
def connect(self, persistent=False):
"""
Start the zk_conn object and connect to the cluster, then load the current schema version
"""
try:
self.zk_conn.start()
if persistent:
self.zk_conn.add_listener(self.listener)
except Exception as e:
raise ZKConnectionException(self, e)
def disconnect(self):
"""
Stop and close the zk_conn object and disconnect from the cluster
The class instance may be reused later (avoids persistent connections)
"""
self.zk_conn.stop()
self.zk_conn.close()
#
# Schema helper actions
#
def get_schema_path(self, key):
if isinstance(key, tuple):
# This is a key tuple with both an ipath and an item
if len(key) == 2:
# 2-length normal tuple
ipath, item = key
elif len(key) == 4:
# 4-length sub-level tuple
ipath, item, sub_ipath, sub_item = key
return self.schema.path(ipath, item=item) + self.schema.path(sub_ipath, item=sub_item)
else:
# This is an invalid key
return None
elif isinstance(key, str):
# This is a key string with just an ipath
ipath = key
item = None
# This is a raw key path, used by backup/restore functionality
if re.match(r'^/', ipath):
return ipath
else:
# This is an invalid key
return None
return self.schema.path(ipath, item=item)
#
# Key Actions
#
def exists(self, key):
"""
Check if a key exists
"""
path = self.get_schema_path(key)
stat = self.zk_conn.exists(path)
if stat:
return True
else:
return False
def read(self, key):
"""
Read data from a key
"""
if self.exists(key):
path = self.get_schema_path(key)
data = self.zk_conn.get(path)[0].decode(self.encoding)
else:
data = None
return data
def write(self, kvpairs):
"""
Create or update one or more keys' data
"""
if type(kvpairs) is not list:
self.log("ZKHandler error: Key-value sequence is not a list", state='e')
return False
transaction = self.zk_conn.transaction()
for kvpair in (kvpairs):
if type(kvpair) is not tuple:
self.log("ZKHandler error: Key-value pair '{}' is not a tuple".format(kvpair), state='e')
return False
key = kvpair[0]
value = kvpair[1]
path = self.get_schema_path(key)
if not self.exists(key):
# Creating a new key
transaction.create(path, str(value).encode(self.encoding))
else:
# Updating an existing key
data = self.zk_conn.get(path)
version = data[1].version
# Validate the expected version after the execution
new_version = version + 1
# Update the data
transaction.set_data(path, str(value).encode(self.encoding))
# Check the data
try:
transaction.check(path, new_version)
except TypeError:
self.log("ZKHandler error: Key '{}' does not match expected version".format(path), state='e')
return False
try:
transaction.commit()
return True
except Exception as e:
self.log("ZKHandler error: Failed to commit transaction: {}".format(e), state='e')
return False
def delete(self, keys, recursive=True):
"""
Delete a key or list of keys (defaults to recursive)
"""
if type(keys) is not list:
keys = [keys]
for key in keys:
path = self.get_schema_path(key)
if self.exists(key):
try:
self.zk_conn.delete(path, recursive=recursive)
except Exception as e:
self.log("ZKHandler error: Failed to delete key {}: {}".format(path, e), state='e')
return False
return True
def children(self, key):
"""
Lists all children of a key
"""
path = self.get_schema_path(key)
return self.zk_conn.get_children(path)
def rename(self, kkpairs):
"""
Rename one or more keys to a new value
"""
if type(kkpairs) is not list:
self.log("ZKHandler error: Key-key sequence is not a list", state='e')
return False
transaction = self.zk_conn.transaction()
def rename_element(transaction, source_path, destination_path):
data = self.zk_conn.get(source_path)[0]
transaction.create(destination_path, data)
if self.children(source_path):
for child_path in self.children(source_path):
child_source_path = "{}/{}".format(source_path, child_path)
child_destination_path = "{}/{}".format(destination_path, child_path)
rename_element(transaction, child_source_path, child_destination_path)
transaction.delete(source_path)
for kkpair in (kkpairs):
if type(kkpair) is not tuple:
self.log("ZKHandler error: Key-key pair '{}' is not a tuple".format(kkpair), state='e')
return False
source_key = kkpair[0]
source_path = self.get_schema_path(source_key)
destination_key = kkpair[1]
destination_path = self.get_schema_path(destination_key)
if not self.exists(source_key):
self.log("ZKHander error: Source key '{}' does not exist".format(source_path), state='e')
return False
if self.exists(destination_key):
self.log("ZKHander error: Destination key '{}' already exists".format(destination_path), state='e')
return False
rename_element(transaction, source_path, destination_path)
try:
transaction.commit()
return True
except Exception as e:
self.log("ZKHandler error: Failed to commit transaction: {}".format(e), state='e')
return False
#
# Lock actions
#
def readlock(self, key):
"""
Acquires a read lock on a key
"""
count = 1
lock = None
path = self.get_schema_path(key)
while True:
try:
lock_id = str(uuid.uuid1())
lock = self.zk_conn.ReadLock(path, lock_id)
break
except Exception as e:
if count > 5:
self.log("ZKHandler warning: Failed to acquire read lock after 5 tries: {}".format(e), state='e')
break
else:
time.sleep(0.5)
count += 1
continue
return lock
def writelock(self, key):
"""
Acquires a write lock on a key
"""
count = 1
lock = None
path = self.get_schema_path(key)
while True:
try:
lock_id = str(uuid.uuid1())
lock = self.zk_conn.WriteLock(path, lock_id)
break
except Exception as e:
if count > 5:
self.log("ZKHandler warning: Failed to acquire write lock after 5 tries: {}".format(e), state='e')
break
else:
time.sleep(0.5)
count += 1
continue
return lock
def exclusivelock(self, key):
"""
Acquires an exclusive lock on a key
"""
count = 1
lock = None
path = self.get_schema_path(key)
while True:
try:
lock_id = str(uuid.uuid1())
lock = self.zk_conn.Lock(path, lock_id)
break
except Exception as e:
if count > 5:
self.log("ZKHandler warning: Failed to acquire exclusive lock after 5 tries: {}".format(e), state='e')
break
else:
time.sleep(0.5)
count += 1
continue
return lock
#
# Schema classes
#
class ZKSchema(object):
# Current version
_version = 1
# Root for doing nested keys
_schema_root = ''
# Primary schema definition for the current version
_schema = {
'version': f'{_version}',
'root': f'{_schema_root}',
# Base schema defining core keys; this is all that is initialized on cluster init()
'base': {
'root': f'{_schema_root}',
'schema': f'{_schema_root}/schema',
'schema.version': f'{_schema_root}/schema/version',
'config': f'{_schema_root}/config',
'config.maintenance': f'{_schema_root}/config/maintenance',
'config.primary_node': f'{_schema_root}/config/primary_node',
'config.primary_node.sync_lock': f'{_schema_root}/config/primary_node/sync_lock',
'config.upstream_ip': f'{_schema_root}/config/upstream_ip',
'config.migration_target_selector': f'{_schema_root}/config/migration_target_selector',
'cmd': f'{_schema_root}/cmd',
'cmd.node': f'{_schema_root}/cmd/nodes',
'cmd.domain': f'{_schema_root}/cmd/domains',
'cmd.ceph': f'{_schema_root}/cmd/ceph',
'node': f'{_schema_root}/nodes',
'domain': f'{_schema_root}/domains',
'network': f'{_schema_root}/networks',
'storage': f'{_schema_root}/ceph',
'storage.util': f'{_schema_root}/ceph/util',
'osd': f'{_schema_root}/ceph/osds',
'pool': f'{_schema_root}/ceph/pools',
'volume': f'{_schema_root}/ceph/volumes',
'snapshot': f'{_schema_root}/ceph/snapshots',
},
# The schema of an individual node entry (/nodes/{node_name})
'node': {
'name': '', # The root key
'keepalive': '/keepalive',
'mode': '/daemonmode',
'data.active_schema': '/activeschema',
'data.latest_schema': '/latestschema',
'data.static': '/staticdata',
'running_domains': '/runningdomains',
'count.provisioned_domains': '/domainscount',
'count.networks': '/networkscount',
'state.daemon': '/daemonstate',
'state.router': '/routerstate',
'state.domain': '/domainstate',
'cpu.load': '/cpuload',
'vcpu.allocated': '/vcpualloc',
'memory.total': '/memtotal',
'memory.used': '/memused',
'memory.free': '/memfree',
'memory.allocated': '/memalloc',
'memory.provisioned': '/memprov',
'ipmi.hostname': '/ipmihostname',
'ipmi.username': '/ipmiusername',
'ipmi.password': '/ipmipassword',
'sriov': '/sriov',
'sriov.pf': '/sriov/pf',
'sriov.vf': '/sriov/vf',
},
# The schema of an individual SR-IOV PF entry (/nodes/{node_name}/sriov/pf/{pf})
'sriov_pf': {
'phy': '', # The root key
'mtu': '/mtu',
'vfcount': '/vfcount'
},
# The schema of an individual SR-IOV VF entry (/nodes/{node_name}/sriov/vf/{vf})
'sriov_vf': {
'phy': '', # The root key
'pf': '/pf',
'mtu': '/mtu',
'mac': '/mac',
'config': '/config',
'config.vlan_id': '/config/vlan_id',
'config.vlan_qos': '/config/vlan_qos',
'config.tx_rate_min': '/config/tx_rate_min',
'config.tx_rate_max': '/config/tx_rate_max',
'config.spoof_check': '/config/spoof_check',
'config.link_state': '/config/link_state',
'config.trust': '/config/trust',
'config.query_rss': '/config/query_rss',
'used': '/used',
'used_by': '/used_by'
},
# The schema of an individual domain entry (/domains/{domain_uuid})
'domain': {
'name': '', # The root key
'xml': '/xml',
'state': '/state',
'profile': '/profile',
'stats': '/stats',
'node': '/node',
'last_node': '/lastnode',
'failed_reason': '/failedreason',
'storage.volumes': '/rbdlist',
'console.log': '/consolelog',
'console.vnc': '/vnc',
'meta.autostart': '/node_autostart',
'meta.migrate_method': '/migration_method',
'meta.node_selector': '/node_selector',
'meta.node_limit': '/node_limit',
'migrate.sync_lock': '/migrate_sync_lock'
},
# The schema of an individual network entry (/networks/{vni})
'network': {
'vni': '', # The root key
'type': '/nettype',
'rule': '/firewall_rules',
'rule.in': '/firewall_rules/in',
'rule.out': '/firewall_rules/out',
'nameservers': '/name_servers',
'domain': '/domain',
'reservation': '/dhcp4_reservations',
'lease': '/dhcp4_leases',
'ip4.gateway': '/ip4_gateway',
'ip4.network': '/ip4_network',
'ip4.dhcp': '/dhcp4_flag',
'ip4.dhcp_start': '/dhcp4_start',
'ip4.dhcp_end': '/dhcp4_end',
'ip6.gateway': '/ip6_gateway',
'ip6.network': '/ip6_network',
'ip6.dhcp': '/dhcp6_flag'
},
# The schema of an individual network DHCP(v4) reservation entry (/networks/{vni}/dhcp4_reservations/{mac})
'reservation': {
'mac': '', # The root key
'ip': '/ipaddr',
'hostname': '/hostname'
},
# The schema of an individual network DHCP(v4) lease entry (/networks/{vni}/dhcp4_leases/{mac})
'lease': {
'mac': '', # The root key
'ip': '/ipaddr',
'hostname': '/hostname',
'expiry': '/expiry',
'client_id': '/clientid'
},
# The schema for an individual network ACL entry (/networks/{vni}/firewall_rules/(in|out)/{acl}
'rule': {
'description': '', # The root key
'rule': '/rule',
'order': '/order'
},
# The schema of an individual OSD entry (/ceph/osds/{osd_id})
'osd': {
'id': '', # The root key
'node': '/node',
'device': '/device',
'stats': '/stats'
},
# The schema of an individual pool entry (/ceph/pools/{pool_name})
'pool': {
'name': '', # The root key
'pgs': '/pgs',
'stats': '/stats'
},
# The schema of an individual volume entry (/ceph/volumes/{pool_name}/{volume_name})
'volume': {
'name': '', # The root key
'stats': '/stats'
},
# The schema of an individual snapshot entry (/ceph/volumes/{pool_name}/{volume_name}/{snapshot_name})
'snapshot': {
'name': '', # The root key
'stats': '/stats'
}
}
# Properties
@property
def schema_root(self):
return self._schema_root
@schema_root.setter
def schema_root(self, schema_root):
self._schema_root = schema_root
@property
def version(self):
return int(self._version)
@version.setter
def version(self, version):
self._version = int(version)
@property
def schema(self):
return self._schema
@schema.setter
def schema(self, schema):
self._schema = schema
def __init__(self):
pass
def __repr__(self):
return f'ZKSchema({self.version})'
def __lt__(self, other):
if self.version < other.version:
return True
else:
return False
def __le__(self, other):
if self.version <= other.version:
return True
else:
return False
def __gt__(self, other):
if self.version > other.version:
return True
else:
return False
def __ge__(self, other):
if self.version >= other.version:
return True
else:
return False
def __eq__(self, other):
if self.version == other.version:
return True
else:
return False
# Load the schema of a given version from a file
def load(self, version, quiet=False):
if not quiet:
print(f'Loading schema version {version}')
with open(f'daemon_lib/migrations/versions/{version}.json', 'r') as sfh:
self.schema = json.load(sfh)
self.version = self.schema.get('version')
# Get key paths
def path(self, ipath, item=None):
itype, *ipath = ipath.split('.')
if item is None:
return self.schema.get(itype).get('.'.join(ipath))
else:
base_path = self.schema.get('base').get(itype, None)
if base_path is None:
# This should only really happen for second-layer key types where the helper functions join them together
base_path = ''
sub_path = self.schema.get(itype).get('.'.join(ipath))
if sub_path is None:
sub_path = ''
return f'{base_path}/{item}{sub_path}'
# Get keys of a schema location
def keys(self, itype=None):
if itype is None:
return list(self.schema.get('base').keys())
else:
return list(self.schema.get(itype).keys())
# Get the active version of a cluster's schema
def get_version(self, zkhandler):
try:
current_version = zkhandler.read(self.path('base.schema.version'))
except NoNodeError:
current_version = 0
return current_version
# Validate an active schema against a Zookeeper cluster
def validate(self, zkhandler, logger=None):
result = True
# Walk the entire tree checking our schema
for elem in ['base']:
for key in self.keys(elem):
kpath = f'{elem}.{key}'
if not zkhandler.zk_conn.exists(self.path(kpath)):
if logger is not None:
logger.out(f'Key not found: {self.path(kpath)}', state='w')
result = False
for elem in ['node', 'domain', 'network', 'osd', 'pool']:
# First read all the subelements of the key class
for child in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
# For each key in the schema for that particular elem
for ikey in self.keys(elem):
kpath = f'{elem}.{ikey}'
# Validate that the key exists for that child
if not zkhandler.zk_conn.exists(self.path(kpath, child)):
if logger is not None:
logger.out(f'Key not found: {self.path(kpath, child)}', state='w')
result = False
# Continue for child keys under network (reservation, acl)
if elem in ['network'] and ikey in ['reservation', 'rule.in', 'rule.out']:
if ikey in ['rule.in', 'rule.out']:
sikey = 'rule'
else:
sikey = ikey
npath = self.path(f'{elem}.{ikey}', child)
for nchild in zkhandler.zk_conn.get_children(npath):
nkpath = f'{npath}/{nchild}'
for esikey in self.keys(sikey):
nkipath = f'{nkpath}/{esikey}'
if not zkhandler.zk_conn.exists(nkipath):
result = False
# One might expect child keys under node (specifically, sriov.pf and sriov.vf) to be
# managed here as well, but those are created automatically every time pvcnoded starts
# and thus never need to be validated or applied.
# These two have several children layers that must be parsed through
for elem in ['volume']:
# First read all the subelements of the key class (pool layer)
for pchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
# Finally read all the subelements of the key class (volume layer)
for vchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}') + f'/{pchild}'):
child = f'{pchild}/{vchild}'
# For each key in the schema for that particular elem
for ikey in self.keys(elem):
kpath = f'{elem}.{ikey}'
# Validate that the key exists for that child
if not zkhandler.zk_conn.exists(self.path(kpath, child)):
if logger is not None:
logger.out(f'Key not found: {self.path(kpath, child)}', state='w')
result = False
for elem in ['snapshot']:
# First read all the subelements of the key class (pool layer)
for pchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
# Next read all the subelements of the key class (volume layer)
for vchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}') + f'/{pchild}'):
# Finally read all the subelements of the key class (volume layer)
for schild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}') + f'/{pchild}/{vchild}'):
child = f'{pchild}/{vchild}/{schild}'
# For each key in the schema for that particular elem
for ikey in self.keys(elem):
kpath = f'{elem}.{ikey}'
# Validate that the key exists for that child
if not zkhandler.zk_conn.exists(self.path(kpath, child)):
if logger is not None:
logger.out(f'Key not found: {self.path(kpath, child)}', state='w')
result = False
return result
# Apply the current schema to the cluster
def apply(self, zkhandler):
# Walk the entire tree checking our schema
for elem in ['base']:
for key in self.keys(elem):
kpath = f'{elem}.{key}'
if not zkhandler.zk_conn.exists(self.path(kpath)):
# Ensure that we create base.schema.version with the current valid version value
if kpath == 'base.schema.version':
data = str(self.version)
else:
data = ''
zkhandler.zk_conn.create(self.path(kpath), data.encode(zkhandler.encoding))
for elem in ['node', 'domain', 'network', 'osd', 'pool']:
# First read all the subelements of the key class
for child in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
# For each key in the schema for that particular elem
for ikey in self.keys(elem):
kpath = f'{elem}.{ikey}'
# Validate that the key exists for that child
if not zkhandler.zk_conn.exists(self.path(kpath, child)):
zkhandler.zk_conn.create(self.path(kpath, child), ''.encode(zkhandler.encoding))
# Continue for child keys under network (reservation, acl)
if elem in ['network'] and ikey in ['reservation', 'rule.in', 'rule.out']:
if ikey in ['rule.in', 'rule.out']:
sikey = 'rule'
else:
sikey = ikey
npath = self.path(f'{elem}.{ikey}', child)
for nchild in zkhandler.zk_conn.get_children(npath):
nkpath = f'{npath}/{nchild}'
for esikey in self.keys(sikey):
nkipath = f'{nkpath}/{esikey}'
if not zkhandler.zk_conn.exists(nkipath):
zkhandler.zk_conn.create(nkipath, ''.encode(zkhandler.encoding))
# One might expect child keys under node (specifically, sriov.pf and sriov.vf) to be
# managed here as well, but those are created automatically every time pvcnoded starts
# and thus never need to be validated or applied.
# These two have several children layers that must be parsed through
for elem in ['volume']:
# First read all the subelements of the key class (pool layer)
for pchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
# Finally read all the subelements of the key class (volume layer)
for vchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}') + f'/{pchild}'):
child = f'{pchild}/{vchild}'
# For each key in the schema for that particular elem
for ikey in self.keys(elem):
kpath = f'{elem}.{ikey}'
# Validate that the key exists for that child
if not zkhandler.zk_conn.exists(self.path(kpath, child)):
zkhandler.zk_conn.create(self.path(kpath, child), ''.encode(zkhandler.encoding))
for elem in ['snapshot']:
# First read all the subelements of the key class (pool layer)
for pchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
# Next read all the subelements of the key class (volume layer)
for vchild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}') + f'/{pchild}'):
# Finally read all the subelements of the key class (volume layer)
for schild in zkhandler.zk_conn.get_children(self.path(f'base.{elem}') + f'/{pchild}/{vchild}'):
child = f'{pchild}/{vchild}/{schild}'
# For each key in the schema for that particular elem
for ikey in self.keys(elem):
kpath = f'{elem}.{ikey}'
# Validate that the key exists for that child
if not zkhandler.zk_conn.exists(self.path(kpath, child)):
zkhandler.zk_conn.create(self.path(kpath, child), ''.encode(zkhandler.encoding))
# Migrate key diffs
def run_migrate(self, zkhandler, changes):
diff_add = changes['add']
diff_remove = changes['remove']
diff_rename = changes['rename']
add_tasks = list()
for key in diff_add.keys():
add_tasks.append((diff_add[key], ''))
remove_tasks = list()
for key in diff_remove.keys():
remove_tasks.append(diff_remove[key])
rename_tasks = list()
for key in diff_rename.keys():
rename_tasks.append((diff_rename[key]['from'], diff_rename[key]['to']))
zkhandler.write(add_tasks)
zkhandler.delete(remove_tasks)
zkhandler.rename(rename_tasks)
# Migrate from older to newer schema
def migrate(self, zkhandler, new_version):
# Determine the versions in between
versions = ZKSchema.find_all(start=self.version, end=new_version)
if versions is None:
return
for version in versions:
# Create a new schema at that version
zkschema_new = ZKSchema()
zkschema_new.load(version)
# Get a list of changes
changes = ZKSchema.key_diff(self, zkschema_new)
# Apply those changes
self.run_migrate(zkhandler, changes)
# Rollback from newer to older schema
def rollback(self, zkhandler, old_version):
# Determine the versions in between
versions = ZKSchema.find_all(start=old_version - 1, end=self.version - 1)
if versions is None:
return
versions.reverse()
for version in versions:
# Create a new schema at that version
zkschema_old = ZKSchema()
zkschema_old.load(version)
# Get a list of changes
changes = ZKSchema.key_diff(self, zkschema_old)
# Apply those changes
self.run_migrate(zkhandler, changes)
@classmethod
def key_diff(cls, schema_a, schema_b):
# schema_a = current
# schema_b = new
diff_add = dict()
diff_remove = dict()
diff_rename = dict()
# Parse through each core element
for elem in ['base', 'node', 'domain', 'network', 'osd', 'pool', 'volume', 'snapshot']:
set_a = set(schema_a.keys(elem))
set_b = set(schema_b.keys(elem))
diff_keys = set_a ^ set_b
for item in diff_keys:
elem_item = f'{elem}.{item}'
if item not in schema_a.keys(elem) and item in schema_b.keys(elem):
diff_add[elem_item] = schema_b.path(elem_item)
if item in schema_a.keys(elem) and item not in schema_b.keys(elem):
diff_remove[elem_item] = schema_a.path(elem_item)
for item in set_b:
elem_item = f'{elem}.{item}'
if schema_a.path(elem_item) is not None and \
schema_b.path(elem_item) is not None and \
schema_a.path(elem_item) != schema_b.path(elem_item):
diff_rename[elem_item] = {'from': schema_a.path(elem_item), 'to': schema_b.path(elem_item)}
return {'add': diff_add, 'remove': diff_remove, 'rename': diff_rename}
# Load in the schemal of the current cluster
@classmethod
def load_current(cls, zkhandler):
new_instance = cls()
version = new_instance.get_version(zkhandler)
new_instance.load(version)
return new_instance
# Write the latest schema to a file
@classmethod
def write(cls):
schema_file = 'daemon_lib/migrations/versions/{}.json'.format(cls._version)
with open(schema_file, 'w') as sfh:
json.dump(cls._schema, sfh)
# Static methods for reading information from the files
@staticmethod
def find_all(start=0, end=None):
versions = list()
for version in os.listdir('daemon_lib/migrations/versions'):
sequence_id = int(version.split('.')[0])
if end is None:
if sequence_id > start:
versions.append(sequence_id)
else:
if sequence_id > start and sequence_id <= end:
versions.append(sequence_id)
if len(versions) > 0:
return versions
else:
return None
@staticmethod
def find_latest():
latest_version = 0
for version in os.listdir('daemon_lib/migrations/versions'):
sequence_id = int(version.split('.')[0])
if sequence_id > latest_version:
latest_version = sequence_id
return latest_version