Synnefo » snf-ganeti

#!/usr/bin/python

#

# Copyright (C) 2006, 2007 Google Inc.

#

# 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; either version 2 of the License, or

# (at your option) any later version.

#

# 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, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Module implementing the logic behind the cluster operations

This module implements the logic for doing operations in the cluster. There

are two kinds of classes defined:

  - logical units, which know how to deal with their specific opcode only

  - the processor, which dispatches the opcodes to their logical units

"""

from ganeti import opcodes

from ganeti import constants

from ganeti import errors

from ganeti import rpc

from ganeti import cmdlib

from ganeti import config

from ganeti import ssconf

class Processor(object):

  """Object which runs OpCodes"""

  DISPATCH_TABLE = {

    # Cluster

    opcodes.OpInitCluster: cmdlib.LUInitCluster,

    opcodes.OpDestroyCluster: cmdlib.LUDestroyCluster,

    opcodes.OpQueryClusterInfo: cmdlib.LUQueryClusterInfo,

    opcodes.OpClusterCopyFile: cmdlib.LUClusterCopyFile,

    opcodes.OpRunClusterCommand: cmdlib.LURunClusterCommand,

    opcodes.OpVerifyCluster: cmdlib.LUVerifyCluster,

    opcodes.OpMasterFailover: cmdlib.LUMasterFailover,

    opcodes.OpDumpClusterConfig: cmdlib.LUDumpClusterConfig,

    # node lu

    opcodes.OpAddNode: cmdlib.LUAddNode,

    opcodes.OpQueryNodes: cmdlib.LUQueryNodes,

    opcodes.OpQueryNodeData: cmdlib.LUQueryNodeData,

    opcodes.OpQueryNodeVolumes: cmdlib.LUQueryNodeVolumes,

    opcodes.OpRemoveNode: cmdlib.LURemoveNode,

    # instance lu

    opcodes.OpCreateInstance: cmdlib.LUCreateInstance,

    opcodes.OpReinstallInstance: cmdlib.LUReinstallInstance,

    opcodes.OpRemoveInstance: cmdlib.LURemoveInstance,

    opcodes.OpActivateInstanceDisks: cmdlib.LUActivateInstanceDisks,

    opcodes.OpShutdownInstance: cmdlib.LUShutdownInstance,

    opcodes.OpStartupInstance: cmdlib.LUStartupInstance,

    opcodes.OpDeactivateInstanceDisks: cmdlib.LUDeactivateInstanceDisks,

    opcodes.OpAddMDDRBDComponent: cmdlib.LUAddMDDRBDComponent,

    opcodes.OpRemoveMDDRBDComponent: cmdlib.LURemoveMDDRBDComponent,

    opcodes.OpReplaceDisks: cmdlib.LUReplaceDisks,

    opcodes.OpFailoverInstance: cmdlib.LUFailoverInstance,

    opcodes.OpConnectConsole: cmdlib.LUConnectConsole,

    opcodes.OpQueryInstances: cmdlib.LUQueryInstances,

    opcodes.OpQueryInstanceData: cmdlib.LUQueryInstanceData,

    opcodes.OpSetInstanceParms: cmdlib.LUSetInstanceParms,

    # os lu

    opcodes.OpDiagnoseOS: cmdlib.LUDiagnoseOS,

    # exports lu

    opcodes.OpQueryExports: cmdlib.LUQueryExports,

    opcodes.OpExportInstance: cmdlib.LUExportInstance,

    # tags lu

    opcodes.OpGetTags: cmdlib.LUGetTags,

    opcodes.OpSetTag: cmdlib.LUAddTag,

    opcodes.OpDelTag: cmdlib.LUDelTag,

    }

  def __init__(self):

    """Constructor for Processor

    """

    self.cfg = None

    self.sstore = None

  def ExecOpCode(self, op, feedback_fn):

    """Execute an opcode.

    Args:

     - cfg: the configuration in which we execute this opcode

     - opcode: the opcode to be executed

     - feedback_fn: the feedback function (taking one string) to be run when

                    interesting events are happening

    """

    if not isinstance(op, opcodes.OpCode):

      raise errors.ProgrammerError("Non-opcode instance passed"

                                   " to ExecOpcode")

    lu_class = self.DISPATCH_TABLE.get(op.__class__, None)

    if lu_class is None:

      raise errors.OpCodeUnknown("Unknown opcode")

    if lu_class.REQ_CLUSTER and self.cfg is None:

      self.cfg = config.ConfigWriter()

      self.sstore = ssconf.SimpleStore()

    lu = lu_class(self, op, self.cfg, self.sstore)

    lu.CheckPrereq()

    do_hooks = lu_class.HPATH is not None

    if do_hooks:

      hm = HooksMaster(rpc.call_hooks_runner, self.cfg, self.sstore, lu)

      hm.RunPhase(constants.HOOKS_PHASE_PRE)

    result = lu.Exec(feedback_fn)

    if do_hooks:

      hm.RunPhase(constants.HOOKS_PHASE_POST)

    return result

  def ChainOpCode(self, op, feedback_fn):

    """Chain and execute an opcode.

    This is used by LUs when they need to execute a child LU.

    Args:

     - opcode: the opcode to be executed

     - feedback_fn: the feedback function (taking one string) to be run when

                    interesting events are happening

    """

    if not isinstance(op, opcodes.OpCode):

      raise errors.ProgrammerError("Non-opcode instance passed"

                                   " to ExecOpcode")

    lu_class = self.DISPATCH_TABLE.get(op.__class__, None)

    if lu_class is None:

      raise errors.OpCodeUnknown("Unknown opcode")

    if lu_class.REQ_CLUSTER and self.cfg is None:

      self.cfg = config.ConfigWriter()

      self.sstore = ssconf.SimpleStore()

    do_hooks = lu_class.HPATH is not None

    lu = lu_class(self, op, self.cfg, self.sstore)

    lu.CheckPrereq()

    #if do_hooks:

    #  hm = HooksMaster(rpc.call_hooks_runner, self.cfg, self.sstore, lu)

    #  hm.RunPhase(constants.HOOKS_PHASE_PRE)

    result = lu.Exec(feedback_fn)

    #if do_hooks:

    #  hm.RunPhase(constants.HOOKS_PHASE_POST)

    return result

class HooksMaster(object):

  """Hooks master.

  This class distributes the run commands to the nodes based on the

  specific LU class.

  In order to remove the direct dependency on the rpc module, the

  constructor needs a function which actually does the remote

  call. This will usually be rpc.call_hooks_runner, but any function

  which behaves the same works.

  """

  def __init__(self, callfn, cfg, sstore, lu):

    self.callfn = callfn

    self.cfg = cfg

    self.sstore = sstore

    self.lu = lu

    self.op = lu.op

    self.hpath = self.lu.HPATH

    self.env, node_list_pre, node_list_post = self._BuildEnv()

    self.node_list = {constants.HOOKS_PHASE_PRE: node_list_pre,

                      constants.HOOKS_PHASE_POST: node_list_post}

  def _BuildEnv(self):

    """Compute the environment and the target nodes.

    Based on the opcode and the current node list, this builds the

    environment for the hooks and the target node list for the run.

    """

    env = {

      "PATH": "/sbin:/bin:/usr/sbin:/usr/bin",

      "GANETI_HOOKS_VERSION": constants.HOOKS_VERSION,

      "GANETI_OP_CODE": self.op.OP_ID,

      "GANETI_OBJECT_TYPE": self.lu.HTYPE,

      }

    lu_env, lu_nodes_pre, lu_nodes_post = self.lu.BuildHooksEnv()

    if lu_env:

      for key in lu_env:

        env["GANETI_" + key] = lu_env[key]

    if self.sstore is not None:

      env["GANETI_CLUSTER"] = self.sstore.GetClusterName()

      env["GANETI_MASTER"] = self.sstore.GetMasterNode()

    for key in env:

      if not isinstance(env[key], str):

        env[key] = str(env[key])

    return env, frozenset(lu_nodes_pre), frozenset(lu_nodes_post)

  def RunPhase(self, phase):

    """Run all the scripts for a phase.

    This is the main function of the HookMaster.

    """

    if not self.node_list[phase]:

      # empty node list, we should not attempt to run this

      # as most probably we're in the cluster init phase and the rpc client

      # part can't even attempt to run

      return

    self.env["GANETI_HOOKS_PHASE"] = str(phase)

    results = self.callfn(self.node_list[phase], self.hpath, phase, self.env)

    if phase == constants.HOOKS_PHASE_PRE:

      errs = []

      if not results:

        raise errors.HooksFailure("Communication failure")

      for node_name in results:

        res = results[node_name]

        if res is False or not isinstance(res, list):

          raise errors.HooksFailure("Communication failure to node %s" %

                                    node_name)

        for script, hkr, output in res:

          if hkr == constants.HKR_FAIL:

            output = output.strip().encode("string_escape")

            errs.append((node_name, script, output))

      if errs:

        raise errors.HooksAbort(errs)