This branch commit refactors the pvcnoded component to better adhere to good programming practices. The previous Daemon.py was a massive file which contained almost 2000 lines of direct, root-level code which was directly imported. Not only was this poor practice, but this resulted in a nigh-unmaintainable file which was hard even for me to understand. This refactoring splits a large section of the code from Daemon.py into separate small modules and functions in the `util/` directory. This will hopefully make most of the functionality easy to find and modify without having to dig through a single large file. Further the existing subcomponents have been moved to the `objects/` directory which clearly separates them. Finally, the Daemon.py code has mostly been moved into a function, `entrypoint()`, which is then called from the `pvcnoded.py` stub. An additional item is that most format strings have been replaced by f-strings to make use of the Python 3.6 features in Daemon.py and the utility files.
		
			
				
	
	
		
			133 lines
		
	
	
		
			6.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			6.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
#!/usr/bin/env python3
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# <Filename> - <Description>
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# zookeeper.py - Utility functions for pvcnoded Zookeeper connections
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# Part of the Parallel Virtual Cluster (PVC) system
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#
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#    Copyright (C) 2018-2021 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, version 3.
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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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from daemon_lib.zkhandler import ZKHandler
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import os
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import time
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def connect(logger, config):
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    # Create an instance of the handler
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    zkhandler = ZKHandler(config, logger)
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    try:
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        logger.out('Connecting to Zookeeper on coordinator nodes {}'.format(config['coordinators']), state='i')
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        # Start connection
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        zkhandler.connect(persistent=True)
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    except Exception as e:
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        logger.out('ERROR: Failed to connect to Zookeeper cluster: {}'.format(e), state='e')
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        os._exit(1)
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    logger.out('Validating Zookeeper schema', state='i')
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    try:
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        node_schema_version = int(zkhandler.read(('node.data.active_schema', config['node_hostname'])))
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    except Exception:
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        node_schema_version = int(zkhandler.read('base.schema.version'))
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        zkhandler.write([
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            (('node.data.active_schema', config['node_hostname']), node_schema_version)
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        ])
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    # Load in the current node schema version
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    zkhandler.schema.load(node_schema_version)
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    # Record the latest intalled schema version
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    latest_schema_version = zkhandler.schema.find_latest()
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    logger.out('Latest installed schema is {}'.format(latest_schema_version), state='i')
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    zkhandler.write([
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        (('node.data.latest_schema', config['node_hostname']), latest_schema_version)
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    ])
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    # If we are the last node to get a schema update, fire the master update
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    if latest_schema_version > node_schema_version:
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        node_latest_schema_version = list()
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        for node in zkhandler.children('base.node'):
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            node_latest_schema_version.append(int(zkhandler.read(('node.data.latest_schema', node))))
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        # This is true if all elements of the latest schema version are identical to the latest version,
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        # i.e. they have all had the latest schema installed and ready to load.
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        if node_latest_schema_version.count(latest_schema_version) == len(node_latest_schema_version):
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            zkhandler.write([
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                ('base.schema.version', latest_schema_version)
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            ])
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    return zkhandler, node_schema_version
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def validate_schema(logger, zkhandler):
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    # Validate our schema against the active version
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    if not zkhandler.schema.validate(zkhandler, logger):
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        logger.out('Found schema violations, applying', state='i')
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        zkhandler.schema.apply(zkhandler)
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    else:
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        logger.out('Schema successfully validated', state='o')
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def setup_node(logger, config, zkhandler):
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    # Check if our node exists in Zookeeper, and create it if not
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    if config['daemon_mode'] == 'coordinator':
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        init_routerstate = 'secondary'
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    else:
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        init_routerstate = 'client'
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    if zkhandler.exists(('node', config['node_hostname'])):
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        logger.out(f'Node is {logger.fmt_green}present{logger.fmt_end} in Zookeeper', state='i')
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        # Update static data just in case it's changed
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        zkhandler.write([
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            (('node', config['node_hostname']), config['daemon_mode']),
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            (('node.mode', config['node_hostname']), config['daemon_mode']),
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            (('node.state.daemon', config['node_hostname']), 'init'),
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            (('node.state.router', config['node_hostname']), init_routerstate),
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            (('node.data.static', config['node_hostname']), ' '.join(config['static_data'])),
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            (('node.data.pvc_version', config['node_hostname']), config['pvcnoded_version']),
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            (('node.ipmi.hostname', config['node_hostname']), config['ipmi_hostname']),
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            (('node.ipmi.username', config['node_hostname']), config['ipmi_username']),
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            (('node.ipmi.password', config['node_hostname']), config['ipmi_password']),
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        ])
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    else:
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        logger.out(f'Node is {logger.fmt_red}absent{logger.fmt_end} in Zookeeper; adding new node', state='i')
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        keepalive_time = int(time.time())
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        zkhandler.write([
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            (('node', config['node_hostname']), config['daemon_mode']),
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            (('node.keepalive', config['node_hostname']), str(keepalive_time)),
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            (('node.mode', config['node_hostname']), config['daemon_mode']),
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            (('node.state.daemon', config['node_hostname']), 'init'),
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            (('node.state.domain', config['node_hostname']), 'flushed'),
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            (('node.state.router', config['node_hostname']), init_routerstate),
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            (('node.data.static', config['node_hostname']), ' '.join(config['static_data'])),
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            (('node.data.pvc_version', config['node_hostname']), config['pvcnoded_version']),
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            (('node.ipmi.hostname', config['node_hostname']), config['ipmi_hostname']),
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            (('node.ipmi.username', config['node_hostname']), config['ipmi_username']),
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            (('node.ipmi.password', config['node_hostname']), config['ipmi_password']),
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            (('node.memory.total', config['node_hostname']), '0'),
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            (('node.memory.used', config['node_hostname']), '0'),
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            (('node.memory.free', config['node_hostname']), '0'),
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            (('node.memory.allocated', config['node_hostname']), '0'),
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            (('node.memory.provisioned', config['node_hostname']), '0'),
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            (('node.vcpu.allocated', config['node_hostname']), '0'),
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            (('node.cpu.load', config['node_hostname']), '0.0'),
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            (('node.running_domains', config['node_hostname']), '0'),
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            (('node.count.provisioned_domains', config['node_hostname']), '0'),
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            (('node.count.networks', config['node_hostname']), '0'),
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        ])
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