Ps Pool Member Control

Problem this snippet solves:

This question comes up quite often here on DevCentral: "How can I gracefully shut down my servers for maintenance without disrupting current user sessions?". In fact, I answered this question just the other day again in the iControl forum and figured I'd throw out an application that accomplished this. So I went about writing this application to allow for the graceful shutdown of a given pool member. Of course, the application wouldn't be complete without listing the pools and members for a specified pool as well as allowing for enabling and disabling of the server so I went ahead and included those pieces as a bonus.

Code :

#----------------------------------------------------------------------------
# The contents of this file are subject to the "END USER LICENSE AGREEMENT FOR F5
# Software Development Kit for iControl"; you may not use this file except in
# compliance with the License. The License is included in the iControl
# Software Development Kit.
#
# Software distributed under the License is distributed on an "AS IS"
# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
# the License for the specific language governing rights and limitations
# under the License.
#
# The Original Code is iControl Code and related documentation
# distributed by F5.
#
# The Initial Developer of the Original Code is F5 Networks,
# Inc. Seattle, WA, USA. Portions created by F5 are Copyright (C) 1996-2007 F5 Networks,
# Inc. All Rights Reserved.  iControl (TM) is a registered trademark of F5 Networks, Inc.
#
# Alternatively, the contents of this file may be used under the terms
# of the GNU General Public License (the "GPL"), in which case the
# provisions of GPL are applicable instead of those above.  If you wish
# to allow use of your version of this file only under the terms of the
# GPL and not to allow others to use your version of this file under the
# License, indicate your decision by deleting the provisions above and
# replace them with the notice and other provisions required by the GPL.
# If you do not delete the provisions above, a recipient may use your
# version of this file under either the License or the GPL
#----------------------------------------------------------------------------
param (
  $g_bigip = $null,
  $g_uid = $null,
  $g_pwd = $null,
  $g_pool = $null,
  $g_member = $null,
  $g_mode = $null
);

Set-PSDebug -strict;

#-------------------------------------------------------------------------
# function Write-Usage
#-------------------------------------------------------------------------
function Write-Usage()
{
  Write-Host "Usage: PoolMemberControl.ps1 host uid pwd [pool [member:ip [mode = "enable"|"disable"]]]";
  exit;
}

#-------------------------------------------------------------------------
# Get-Pools
#-------------------------------------------------------------------------
function Get-Pools()
{
  $pool_list = (Get-F5.iControl).LocalLBPool.get_list();
  Write-Host "Available Pools:";
  foreach ($pool in $pool_list)
  {
    Write-Host "  $pool";
  }
}

#-------------------------------------------------------------------------
# Get-PoolMembers
#-------------------------------------------------------------------------
Function Get-PoolMembers()
{
  param($pool_name);
  $member_lists = (Get-F5.iControl).LocalLBPool.get_member((, $pool_name));
  Write-Host "Members for Pool ${pool_name}:"
  foreach($member in $member_lists[0])
  {
    $addr = $member.address;
    $port = $member.port;
    Write-Host "  ${addr}:${port}"
  }
}

#-------------------------------------------------------------------------
# Get-PoolMemberStatus
#-------------------------------------------------------------------------
Function Get-PoolMemberStatus()
{
  param($pool_name, $member);
  $vals = $member.Split( (, ':'));
  $member_addr = $vals[0];
  $member_port = $vals[1];
  $bFound = 0;
  $MemberObjectStatusAofA = (Get-F5.iControl).LocalLBPoolMember.get_object_status((, $pool_name));
  foreach($MemberObjectStatus in $MemberObjectStatusAofA[0])
  {
    $a2 = $MemberObjectStatus.member.address;
    $p2 = $MemberObjectStatus.member.port;
    
    if ( "${member_addr}:${member_port}" -eq "${a2}:${p2}" )
    {
      $Availability = $MemberObjectStatus.object_status.availability_status;
      $Enabled = $MemberObjectStatus.object_status.enabled_status;
      $Description = $MemberObjectStatus.object_status.status_description;
      
      Write-Host "Pool $pool_name, Member ${member_addr}:${member_port} status:"
      Write-Host "  Availability : $Availability"
      Write-Host "  Enabled      : $Enabled"
      Write-Host "  Description  : $Description"
      
      $bFound = 1;
    }
  }
  if ( $bFound -eq 0 )
  {
    Write-Host "Member ${member_addr}:${member_port} could not be found in pool $pool_name!"
  }
}

#-------------------------------------------------------------------------
# Enable-Member
#-------------------------------------------------------------------------
function Enable-Member()
{
  param($pool_name, $member);
  $vals = $member.Split( (, ':'));
  $member_addr = $vals[0];
  $member_port = $vals[1];

  $MemberMonitorState = New-Object -TypeName iControl.LocalLBPoolMemberMemberMonitorState;
  $MemberMonitorState.member = New-Object -TypeName iControl.CommonIPPortDefinition;
  $MemberMonitorState.member.address = $member_addr;
  $MemberMonitorState.member.port = $member_port;
  $MemberMonitorState.monitor_state = "STATE_ENABLED";
  $MemberMonitorStateAofA = New-Object -TypeName "iControl.LocalLBPoolMemberMemberMonitorState[][]" 1,1
  $MemberMonitorStateAofA[0][0] = $MemberMonitorState;
  
  Write-Host "Setting Montior State to Enabled";
  (Get-F5.iControl).LocalLBPoolMember.set_monitor_state( (, $pool_name), $MemberMonitorStateAofA);
  
  $MemberSessionState = New-Object -TypeName iControl.LocalLBPoolMemberMemberSessionState;
  $MemberSessionState.member = New-Object -TypeName iControl.CommonIPPortDefinition;
  $MemberSessionState.member.address = $member_addr;
  $MemberSessionState.member.port = $member_port;
  $MemberSessionState.session_state = "STATE_ENABLED";
  $MemberSessionStateAofA = New-Object -TypeName "iControl.LocalLBPoolMemberMemberSessionState[][]" 1,1
  $MemberSessionStateAofA[0][0] = $MemberSessionState;

  Write-Host "Setting Session Enabled State to Enabled";
  (Get-F5.iControl).LocalLBPoolMember.set_session_enabled_state( (, $pool_name), $MemberSessionStateAofA);

  Get-PoolMemberStatus $pool_name $member
}

#-------------------------------------------------------------------------
# Disable-Member
#-------------------------------------------------------------------------
function Disable-Member()
{
  param($pool_name, $member);
  $vals = $member.Split( (, ':'));
  $member_addr = $vals[0];
  $member_port = $vals[1];
  
  Write-Host "Disabling Session Enabled State...";

  $MemberSessionState = New-Object -TypeName iControl.LocalLBPoolMemberMemberSessionState;
  $MemberSessionState.member = New-Object -TypeName iControl.CommonIPPortDefinition;
  $MemberSessionState.member.address = $member_addr;
  $MemberSessionState.member.port = $member_port;
  $MemberSessionState.session_state = "STATE_DISABLED";
  $MemberSessionStateAofA = New-Object -TypeName "iControl.LocalLBPoolMemberMemberSessionState[][]" 1,1
  $MemberSessionStateAofA[0][0] = $MemberSessionState;

  (Get-F5.iControl).LocalLBPoolMember.set_session_enabled_state( (, $pool_name), $MemberSessionStateAofA);

  Write-Host "Waiting for current connections to drop to zero..."
  $MemberDef = New-Object -TypeName iControl.CommonIPPortDefinition;
  $MemberDef.address = $member_addr;
  $MemberDef.port = $member_port;
  
  $MemberDefAofA = New-Object -TypeName "iControl.CommonIPPortDefinition[][]" 1,1
  $MemberDefAofA[0][0] = $MemberDef;
  
  $cur_connections = 1;
  
  while ( $cur_connections -gt 0 )
  {
    $MemberStatisticsA = (Get-F5.iControl).LocalLBPoolMember.get_statistics( (, $pool_name), $MemberDefAofA);
    $MemberStatisticEntry = $MemberStatisticsA[0].statistics[0];
    $Statistics = $MemberStatisticEntry.statistics;
    foreach ($Statistic in $Statistics)
    {
      $type = $Statistic.type;
      $value = $Statistic.value;
      
      if ( $type -eq "STATISTIC_SERVER_SIDE_CURRENT_CONNECTIONS" )
      {
        # just use the low value.  Odds are there aren't over 2^32 current connections.
        # If your site is this big, you'll have to convert this to a 64 bit number.
        $cur_connections = $value.low;
        Write-Host "Current Connections: $cur_connections"
      }
    }
    Start-Sleep -s 1
  }

  Write-Host "Disabling Monitor State...";

  $MemberMonitorState = New-Object -TypeName iControl.LocalLBPoolMemberMemberMonitorState;
  $MemberMonitorState.member = New-Object -TypeName iControl.CommonIPPortDefinition;
  $MemberMonitorState.member.address = $member_addr;
  $MemberMonitorState.member.port = $member_port;
  $MemberMonitorState.monitor_state = "STATE_DISABLED";
  $MemberMonitorStateAofA = New-Object -TypeName "iControl.LocalLBPoolMemberMemberMonitorState[][]" 1,1
  $MemberMonitorStateAofA[0][0] = $MemberMonitorState;
  
  (Get-F5.iControl).LocalLBPoolMember.set_monitor_state( (, $pool_name), $MemberMonitorStateAofA);
  
  Get-PoolMemberStatus $pool_name $member
}

#-------------------------------------------------------------------------
# Do-Initialize
#-------------------------------------------------------------------------
function Do-Initialize()
{
  if ( (Get-PSSnapin | Where-Object { $_.Name -eq "iControlSnapIn"}) -eq $null )
  {
    Add-PSSnapIn iControlSnapIn
  }
  $success = Initialize-F5.iControl -HostName $g_bigip -Username $g_uid -Password $g_pwd;
  
  return $success;
}

#-------------------------------------------------------------------------
# Main Application Logic
#-------------------------------------------------------------------------
if ( ($g_bigip -eq $null) -or ($g_uid -eq $null) -or ($g_pwd -eq $null) )
{
  Write-Usage;
}

if ( Do-Initialize )
{
  if ( $g_pool -eq $null )
  {
    Get-Pools;
  }
  elseif ( $g_member -eq $null )
  {
    Get-PoolMembers $g_pool;
  }
  elseif ( $g_mode -eq $null )
  {
    Get-PoolMemberStatus $g_pool $g_member;
  }
  else
  {
    switch ($g_mode.ToLower())
    {
      "enable" {
        Enable-Member $g_pool $g_member;
      }
      "disable" {
        Disable-Member $g_pool $g_member;
      }
      default {
        Write-Usage;
      }
    }
  }
}
else
{
  Write-Error "ERROR: iControl subsystem not initialized"
}