Joshua Boniface
f198f62563
Completely restructure the daemon code to move the 4 discrete daemons into a single daemon that can be run on every hypervisor. Introduce the idea of a static list of "coordinator" nodes which are configured at install time to run Zookeeper and FRR in router mode, and which are allowed to take on client network management duties (gateway, DHCP, DNS, etc.) while also allowing them to run VMs (i.e. no dedicated "router" nodes required).
82 lines
2.5 KiB
Python
82 lines
2.5 KiB
Python
#!/usr/bin/env python3
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# zkhandler.py - Secure versioned ZooKeeper updates
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# Part of the Parallel Virtual Cluster (PVC) system
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#
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# Copyright (C) 2018 Joshua M. Boniface <joshua@boniface.me>
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <https://www.gnu.org/licenses/>.
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#
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###############################################################################
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import kazoo.client
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import pvcd.log as log
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# Child list function
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def listchildren(zk_conn, key):
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children = zk_conn.get_children(key)
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return children
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# Key deletion function
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def delete(zk_conn, key):
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zk_conn.delete(key, recursive=True)
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# Data read function
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def readdata(zk_conn, key):
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data_raw = zk_conn.get(key)
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data = data_raw[0].decode('ascii')
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meta = data_raw[1]
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return data
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# Data write function
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def writedata(zk_conn, kv):
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# Start up a transaction
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zk_transaction = zk_conn.transaction()
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# Proceed one KV pair at a time
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for key in sorted(kv):
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data = kv[key]
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if not data:
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data = ''
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# Check if this key already exists or not
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if not zk_conn.exists(key):
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# We're creating a new key
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zk_transaction.create(key, data.encode('ascii'))
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else:
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# We're updating a key with version validation
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orig_data = zk_conn.get(key)
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version = orig_data[1].version
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# Set what we expect the new version to be
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new_version = version + 1
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# Update the data
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zk_transaction.set_data(key, data.encode('ascii'))
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# Set up the check
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try:
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zk_transaction.check(key, new_version)
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except TypeError:
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print('Zookeeper key "{}" does not match expected version'.format(key))
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return False
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# Commit the transaction
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try:
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zk_transaction.commit()
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return True
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except Exception:
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return False
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