MYSQL_README.html   [plain text]

<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"



<title>Postfix MySQL Howto</title>

<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">



<h1><img src="postfix-logo.jpg" width="203" height="98" ALT="">Postfix MySQL Howto</h1>



<p> The Postfix mysql map type allows you to hook up Postfix to a
MySQL database. This implementation allows for multiple mysql
databases: you can use one for a virtual(5) table, one for an
access(5) table, and one for an aliases(5) table if you want.  You
can specify multiple servers for the same database, so that Postfix
can switch to a good database server if one goes bad.  </p>

<p> Busy mail servers using mysql maps will generate lots of
concurrent mysql clients, so the mysql server(s) should be run with
this fact in mind.  You can reduce the number of concurrent mysql
clients by using the Postfix proxymap(8) service. </p>

<h2>Building Postfix with MySQL support</h2>

<p> Note: to use mysql with Debian GNU/Linux's Postfix, all you
need is to install the postfix-mysql package and you're done.
There is no need to recompile Postfix. </p>

<p> The Postfix MySQL client utilizes the mysql client library,
which can be obtained from: </p>

    <p> <br> </p>

<p> In order to build Postfix with mysql map support, you will need to add
-DHAS_MYSQL and -I for the directory containing the mysql headers, and
the mysqlclient library (and libm) to AUXLIBS, for example: </p>

make -f Makefile.init makefiles \
    'CCARGS=-DHAS_MYSQL -I/usr/local/mysql/include' \
    'AUXLIBS=-L/usr/local/mysql/lib -lmysqlclient -lz -lm'

<p> Then, just run 'make'. This requires libz, the compression
library.  Older mysql implementations build without libz. </p>

<h2>Using MySQL tables</h2>

<p> Once Postfix is built with mysql support, you can specify a
map type in like this: </p>

alias_maps = mysql:/etc/postfix/

<p> The file /etc/postfix/ specifies lots of
information telling Postfix how to reference the mysql database.
For a complete description, see the mysql_table(5) manual page. </p>

<h2>Example: local aliases </h2>

# mysql config file for local(8) aliases(5) lookups

# The user name and password to log into the mysql server.
user = someone
password = some_password

# The database name on the servers.
dbname = customer_database

# The table name.
table = mxaliases

# Query components, see below.
select_field = forw_addr
where_field = alias

# You may specify additional_conditions or leave this empty.
additional_conditions = and status = 'paid'

# The above variables will result in a query of the form:
# select forw_addr from mxaliases where alias = '$lookup' and status = 'paid'
# ($lookup is escaped so if it contains single quotes or other odd
# characters, it will not cause trouble).

<h2>Additional notes</h2>

<p> The MySQL configuration interface setup allows for multiple
mysql databases: you can use one for a virtual table, one for an
access table, and one for an aliases table if you want. </p>

<p> Since sites that have a need for multiple mail exchangers may
enjoy the convenience of using a networked mailer database, but do
not want to introduce a single point of failure to their system,
we've included the ability to have Postfix reference multiple hosts
for access to a single mysql map.  This will work if sites set up
mirrored mysql databases on two or more hosts.  Whenever queries
fail with an error at one host, the rest of the hosts will be tried
in random order.  If no mysql server hosts are reachable, then mail
will be deferred until at least one of those hosts is reachable.



<li> The initial version was contributed by Scott Cotton and Joshua
Marcus, IC Group, Inc.

<li>Liviu Daia revised the configuration interface and added the configuration feature.