root / lib / confd / querylib.py @ 48166551
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#!/usr/bin/python
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#
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# Copyright (C) 2009, Google Inc.
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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 2 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, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# 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, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""Ganeti configuration daemon queries library.
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"""
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import logging |
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from ganeti import constants |
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# constants for some common errors to return from a query
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QUERY_UNKNOWN_ENTRY_ERROR = (constants.CONFD_REPL_STATUS_ERROR, |
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constants.CONFD_ERROR_UNKNOWN_ENTRY) |
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QUERY_INTERNAL_ERROR = (constants.CONFD_REPL_STATUS_ERROR, |
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constants.CONFD_ERROR_INTERNAL) |
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class ConfdQuery(object): |
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"""Confd Query base class.
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"""
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def __init__(self, reader): |
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"""Constructor for Confd Query
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@type reader: L{ssconf.SimpleConfigReader}
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@param reader: ConfigReader to use to access the config
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"""
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self.reader = reader
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def Exec(self, query): |
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"""Process a single UDP request from a client.
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Different queries should override this function, which by defaults returns
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a "non-implemented" answer.
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@type query: (undefined)
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@param query: ConfdRequest 'query' field
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@rtype: (integer, undefined)
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@return: status and answer to give to the client
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"""
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status = constants.CONFD_REPL_STATUS_NOTIMPLEMENTED |
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answer = 'not implemented'
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return status, answer
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class PingQuery(ConfdQuery): |
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"""An empty confd query.
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It will return success on an empty argument, and an error on any other argument.
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"""
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def Exec(self, query): |
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"""PingQuery main execution.
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"""
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if query is None: |
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status = constants.CONFD_REPL_STATUS_OK |
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answer = 'ok'
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else:
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status = constants.CONFD_REPL_STATUS_ERROR |
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answer = 'non-empty ping query'
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return status, answer
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class ClusterMasterQuery(ConfdQuery): |
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"""Cluster master query.
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It accepts no arguments, and returns the current cluster master.
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"""
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def Exec(self, query): |
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"""ClusterMasterQuery main execution
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"""
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if query is None: |
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status = constants.CONFD_REPL_STATUS_OK |
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answer = self.reader.GetMasterNode()
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else:
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status = constants.CONFD_REPL_STATUS_ERROR |
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answer = 'master query accepts no query argument'
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return status, answer
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class NodeRoleQuery(ConfdQuery): |
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"""A query for the role of a node.
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It will return one of CONFD_NODE_ROLE_*, or an error for non-existing nodes.
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"""
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def Exec(self, query): |
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"""EmptyQuery main execution
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"""
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node = query |
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if self.reader.GetMasterNode() == node: |
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status = constants.CONFD_REPL_STATUS_OK |
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answer = constants.CONFD_NODE_ROLE_MASTER |
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return status, answer
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flags = self.reader.GetNodeStatusFlags(node)
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if flags is None: |
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return QUERY_UNKNOWN_ENTRY_ERROR
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master_candidate, drained, offline = flags |
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if master_candidate:
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answer = constants.CONFD_NODE_ROLE_CANDIDATE |
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elif drained:
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answer = constants.CONFD_NODE_ROLE_DRAINED |
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elif offline:
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answer = constants.CONFD_NODE_ROLE_OFFLINE |
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else:
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answer = constants.CONFD_NODE_ROLE_REGULAR |
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return constants.CONFD_REPL_STATUS_OK, answer
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class InstanceIpToNodePrimaryIpQuery(ConfdQuery): |
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"""A query for the location of an instance's ip.
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It returns the primary ip of the node hosting the instance having the
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requested ip address, or an error if no such address is known.
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"""
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def Exec(self, query): |
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"""InstanceIpToNodePrimaryIpQuery main execution.
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"""
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instance_ip = query |
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instance = self.reader.GetInstanceByIp(instance_ip)
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if instance is None: |
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return QUERY_UNKNOWN_ENTRY_ERROR
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pnode = self.reader.GetInstancePrimaryNode(instance)
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if pnode is None: |
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# this shouldn't happen
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logging.error("Internal configuration inconsistent (instance-to-pnode)")
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return QUERY_INTERNAL_ERROR
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pnode_primary_ip = self.reader.GetNodePrimaryIp(pnode)
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if pnode_primary_ip is None: |
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# this shouldn't happen
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logging.error("Internal configuration inconsistent (node-to-primary-ip)")
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return QUERY_INTERNAL_ERROR
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return constants.CONFD_REPL_STATUS_OK, pnode_primary_ip
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