path: root/usr.sbin/relayd/relayd.conf.5

.\"	$OpenBSD: relayd.conf.5,v 1.2 2006/12/16 11:52:51 reyk Exp $
.\"
.\" Copyright (c) 2006 Pierre-Yves Ritschard <pyr@spootnik.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd November 1, 2006
.Dt HOSTATED.CONF 5
.Os
.Sh NAME
.Nm hostated.conf
.Nd Host Status daemon configuration file.
.Sh DESCRIPTION
The
.Xr hostated 8
daemon maintains 
.Xr pf 4
tables up to date.
.Sh SECTIONS
The
.Nm
configuration file is divided into four main sections.
.Bl -tag -width xxxx
.It Sy Macros
User-defined variables may be defined and used later, simplifying the
configuration file.
.It Sy Global Configuration
Global settings for
.Xr hostated 8 .
.It Sy Tables
Table definitions describe the content of a 
.Xr pf 4
table and the method used for checking the health of the hosts
they contain.
.It Sy Services
Services will be translated to
.Xr pf 4
rdr rules if their table or backup table have content.
.El
.Sh MACROS
Macros can be defined that will later be expanded in context.
Macro names must start with a letter, and may contain letters, digits,
and underscores.
Macro names may not be reserved words (for example,
.Ic table ,
.Ic service ,
or
.Ic timeout ) .
Macros are not expanded inside quotes.
.Pp
For example:
.Bd -literal -offset indent
www1="10.0.0.1"
www2="10.0.0.2"
table webhosts {
	check tcp
	timeout 300
	real port 80
	host $www1
	host $www2
}
.Ed
.Sh GLOBAL CONFIGURATION
Only one global setting can be set.
.Pp
.Bl -tag -width Ds -compact
.It Xo
.Ic interval Ar number
.Xc
Set the interval in seconds at which the hosts will be checked.
The default interval is 10 seconds.
.El
.Sh TABLES
Tables are used to group a set of hosts that can be checked using the same
method.
Only one health-checking method can be used per table.
Table specific configuration directives are described below.
.Bl -tag -width Ds
.It Ic check tcp
Use a simple tcp connect to check that hosts are up.
.It Ic check icmp
Ping hosts in this table to determine wether they are up or not.
This method will automatically use icmp or icmpv6 depending on the
address family of each host.
.It Ic check http Ar path Ic code Ar number
For each host in the table, verify that retrieving the URL
.Ar path
gives the HTTP return code
.Ar number
.It Ic check http Ar path Ic digest Ar string
For each host in the table, verify that retrieving the URL
.Ar path
produces a content whose SHA1 digest is
.Ar digest .
The digest does not take the HTTP headers into account.
To compute the digest you can use this simple command:
.Bd -literal -offset 2n
ftp -o - http://host[:port]/path | sha1
.Ed
.Pp
This will give you a digest of the form
.Bd -literal -offset 2n
a9993e36476816aba3e25717850c26c9cd0d89d
.Ed
.Pp
that you can use as-is in your digest statement.
.It Ic timeout Ar number
Set the timeout in milliseconds for each host that is checked.
The default timeout is 200 milliseconds.
.It Ic real port Ar number
When using the tcp or http checking methods, use this port to connect
to hosts.
This parameter is mandatory.
Main and backup tables need to have the same real port.
.It Ic host Ar address
Add the host whose address is
.Ar address
to the list of hosts to be checked in this table.
Each table needs at least one host.
.It Ic disable
Start the table disabled, no hosts will be checked in this table.
The table can be later enabled through
.Xr hostatectl 8 .
.El
.Sh SERVICES
Services represent a
.Xr pf 4
rdr rule, they are used to specify which addresses will be redirected 
to the hosts in the specified tables.
The configuration directives that are valid in this context are described
below.
.Bl -tag -width Ds
.It Ic virtual ip Ar address Ic port Ar number
Specify an address and a port that will be used to redirect requests
to the hosts in the main or backup table.
Optionally an interface name can be specified like this.
.Bd -literal -offset indent
interface ``ifname''
.Ed
.Pp
to specify which interface the rdr rule will be enabled on.
.It Ic table Ar name
Specify the main table to be used.
This is mandatory.
.It Ic backup table Ar name
Specify the table to switch to when all hosts in the main table
are seen as down or disabled.
.It Ic disable
Set the service initially disabled.
It can be later enabled through
.It Ic tag Ar name
Automatically tag packets passing through the
.Xr pf 4
rdr rule with the name supplied.
This allows for easier filter rules in your main
.Xr pf 4
configuration.
.Xr hostatectl 5 .
.El
.Sh EXAMPLE
This configuration file would create a service 'www' which load-balances
4 hosts and falls back to 1 host containing a ``sorry page'':
.Bd -literal -offset indent
##
##
www1=front-www1.private.example.com
www2=front-www2.private.example.com
www3=front-www3.private.example.com
www4=front-www4.private.example.com

interval 5

table phphosts {
	timeout 300
	real port 8080
	check http "/" digest 630aa3c2f...
	host $www1
	host $www2
	host $www3
	host $www4
}

table sorryhost {
	check icmp
	disable
	timeout 300
	real port 8080
	host sorryhost.private.example.com
}

service www { 
	virtual ip www.example.com port 8080 interface trunk0
	virtual ip www6.example.com port 80 interface trunk0

	tag HOSTATED
	table phphosts
	backup table sorryhost
}
.Ed
.Sh FILES
.Bl -tag -width "/etc/hostated.conf" -compact
.It Pa /etc/hostated.conf
.Xr hostated 8
configuration file
.El
.Sh SEE ALSO
.Xr hostated 8 ,
.Xr hostatectl 8 .