SYNOPSIS
- wackamole.conf
DESCRIPTION
wackamole reads its configuration information from wackamole.conf (or the file specified with -c on the command line).- Spread
- The spread daemon to which wackamole should connect. Default value is ``4803''
- SpreadRetryInterval
- The time interval between a failed attempt to connect to Spread and the next attempt. Default ``5s''
- Group
- The Spread group overwhich all wackamole instances in the cluster will communicate.
- Control
- The file (unix domain socket) on which wackamole will listen for and to which wackatrl will send out-of-band administrative commands.
- AcquisitionsPerRound
- This is specified within a Balance stanza. This value informs wackamole of the maximum number of interfaces it will assume responsibility for in a single balancing roung. Possible values are non-negative integers and the keywork ``all''
- Interval
-
This is specified within a
Balance
stanza. This value specifies how long each balancing round is to take. The default is
``4s''
Sample Balance stanza:
Balance { AcquisitionsPerRound = all interval = 4s }
- Mature
- Desribing the time interval required before an new node becomes mature and can assume responsibilities. The default value is ``5s''
- Arp-Cache
- This time interval is the interval at which wackamole will recollect local arp cache information and share it with its peers. The default is ``60s''
- Prefer <IP>
- Tells wackamole that this IP address is preferred and that an attempt should be made to assume responsibility for the VIF headed by this IP. Use of this option is discouraged as wackamole can typically make decisions all by its lonesome.
- VirtualInterfaces
-
This stanza describes the virtual interfaces (and the virtual IP addresses
those interfaces contain) that wackamole will manage. A virtual interface
can be a single IP address of the form:
int:IP/CIDR int:IP/CIDRnNET
Interfaces may consist of multiple grouped IPs (that cannot be separated) by specifiying them in braces:
{ int:IP/CIDR int:IP/CIDRnNET int:IP/CIDR }
int in the syntax represents the physical interface on which the IP address will be managed ( e.g. fxp0, eth1, en0, hme0 ). IP is a standard form IPv4 address. CIDR is the numeric CIDR-form netmask (the number of set bits in the netmask). Note that many operating systems ( FreeBSD Solaris Mac OS X recommend that aliases be added with a netmask of 0xffffffff and in these cases, /32 is the appropirate CIDR to use. NET provides a hint to wackamole as to the netspace in which the IP sits. As the netmask directly on the interface is often /32 it often does not illustrate that ARP spoofs can be sent to other IPs (as none lie in its directly attached netspace. NET is a way of effectively telling wackamole the directly attached IP network that ARP responses could be sent to. If NET is not specified, it is assumed to be a n24
With the exception of the interface name and perhaps the netmask, these stanzas must be IDENTICAL across all machines in the cluster. Wackamole manages IP addresses by both index number and IP address, so it is fundamental that the lists look the same and be in the same order.
Sample VirtualInterfaces stanza:
VirtualInterfaces { eth0:10.2.3.11/24 eth0:10.2.3.12/24 eth0:10.2.3.13/24 eth0:10.2.3.13/24 eth0:10.2.3.13/24 }
Sample multi-IP VirtualInterfaces stanza:
VirtualInterfaces { { fxp0:192.168.10.2/32n23 fxp1:192.0.2.2/32n29 } { fxp0:192.168.10.3/32n23 fxp1:192.0.2.3/32n29 } }
EXTENSIBILITY
Wackamole allows for user-defined actions to occur when HA events occur. There are four types of events:- on up
- This occurs when a virtual interface is brought online.
- on down
- This occurs when a virtual interface is brought offline.
- post up
- This occurs after a balancing round during which one or more virtual interfaces where brought online.
- post down
- This occurs after a balancing round during which one or more virtual interfaces where brought offline.
Wackamole allows shared objects to loaded and executed during any of these events by specifying:
RunDynamic module:func event
module is a shared object (or dyld bundle) that can be loaded using the operating systems dynamic run-time loader (dlopen or dyld). func is the name of the symbol to be referenced from that object and invoked. event is one of the four events listed above.
Wackamole also has an optional embedded perl interpreter which allows modules written in perl to be loaded and executed. Perl specific options are:
- PerlUseLib
- Takes a directory as a parameter and is effectively the same as performing use lib within perl.
- PerlUse
- Takes a module as a parameter and performs a use on it making it available for use within wackamole.
The RunDynamic directive envokes perl methods if two colons (::) are used to seperate the module from the func Sample execution of MyModule::DoMagic on a post up event:
PerlUseLib /opt/wackamole/site PerlUse MyModule RunDynamic MyModule::DoMagic post up