Alain M. Lafon

SUN Ray with PS2 keyboards
If you want to hook up a Sun Ray at home, you might want to use your favourite old PS2 keyboard attached via some USB connector. Depending on your keyboard layout you might be disappointed by the result, because it will be standard US. That’s because the PS2 keyboard isn’t designed for the Ray clients and won’t prompt back a valid layout to the server which will then assume a standard scenario.
There is a simple solution to this problem; in the file “/usr/openwin/etc/keytables/keytable.map” edit the entry

6      0       US6.kt

and rewrite it to your favourite layout(British English in this case)

6       0      UK6.kt

There is one drawback however; from this point on this is going to be the single standard fallback layout for all keyboards hooked via SUN Ray clients to your server which won’t report a valid layout themselves. So if you want to use different layouts on different clients you might want to check the xkb option in “/opt/SUNWut/bin/utxconfig”, which I haven’t done until now.

Integration of Databases in the Postfix SMTP server in Debian GNU/Linux

Why would somebody want to let postfix connect to a SQL-database?

• There’s no need to create a real local user for each e-mail account
• SQL-databases can be kept in RAM, so if you have excessive mailing
  on your server, there will be reduced harddisk access
• Management of mailinglists becomes real easy
• /etc/aliases is kept small and simple

Step 1
Install the package “mysql-server” and “mysql-client” if not yet installed.
Log on to your sql-server using the root account:

mysql --user root
mysql> create database postfix_database;
mysql> GRANT ALL PRIVILEGES ON postfix_database \
TO 'postfix'-AT-'localhost' IDENTIFIED BY 'postfix_password' \
WITH GRANT OPTION;
mysql> flush privileges;
mysql> create table postfix.postfix_alias (destination VARCHAR(50), \
alias VARCHAR(50));
mysql> exit;

Now we have created a database called “postfix_database” and a user called
“postfix” who has access to it using his unique password “postfix_password”.
With “flush privileges” we bring the sql-server up to date concerning user rights.
Then we create a table called “postfix_alias” in the database “postfix” with two rows:
“destination” is a text variable where the mail will be relayed to and “alias” is the name
of the mailinglist in my example.

Step 2
Install the package “postfix-mysql”. Besides the needed
library this will bring you the config file “/etc/postfix/mysql-aliases.cf” which we
will modify like this

user = postfix
password = postfix_password
table = postfix_alias
query =  SELECT destination FROM postfix_alias WHERE alias = '%s'
hosts = unix:/var/run/mysqld/mysqld.sock
select_field = destination
where_field = alias

Since postfix runs in a chroot it lacks several information it needs to have;
for example the socket to the mysql daemon. That’s why we provide it
with some bind mounts, which can be done by inserting these lines into
“/etc/fstab”.

/etc/passwd     /var/spool/postfix/etc/passwd           none bind 0 0
/etc/shadow     /var/spool/postfix/etc/shadow           none bind 0 0
/etc/group      /var/spool/postfix/etc/group            none bind 0 0
/var/run/mysqld /var/spool/postfix/var/run/mysqld       none bind 0 0

To update this information the root user has to remount all filesystems
using “mount -a”.

Step 3
We’re done already(almost). All that is still needed is some information in the database.
Single entries can be made with the mysql client like this:

mysql> insert into postfix_alias values \
('someone-AT-somewhere-DOT-de', 'mailinglistname');

Now if you send a mail to “mailinglistname-AT-yourhost-DOT-com” the mail will be relayed to
“someone@somewhere-DOT-de”. That’s it.
I wrote a JSP/Servlet combination in JavaEE to create a webpage where users can
put themselves on or off a mailinglist; you can find it
here or in the
projects folder if you’re interested.

Step 4

Note that installing the package postfix-mysql updated a line in your “/etc/postfix/main.cf”:

alias_maps = hash:/etc/aliases
...
alias_maps = mysql:/etc/postfix/mysql-aliases.cf

There are most likely many more lines in this file, but the important factor is
that the first line mapping to “/etc/aliases” is made obsolete by the second entry.
So if you were using some important relaying in this file you should migrate it.
For this reason I wrote a small
shellscript that was capable to do the job for my setup.

I wrote a small shellscript which converts existing mail
relays in /etc/aliases to a SQL database. It worked for me in this
simple form but I can take no responsibility whatsover for any other
setup.

The usage is pretty much straight forward – simply give the script
the needed information as to where the aliases file is located, the
account for MySQL and so forth.
Note: In the current implementation you have to create the database,
a user and a valid relay table yourself. If you don’t know how to do that
you can extract this information in my howto on migrating Postfix to
MySQL.

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