Debian Package of the Day (static archived copy)

Article submitted by JP Vossen. DebADay needs you more than ever! Please submit good articles about software you like!

Nullmailer is a minimal MTA (Mail Transport Agent) that provides mail delivery services to programs (cron jobs, system integrity checkers, log inspectors, etc.) in a host that otherwise does not require a full MTA like Exim or Postfix. Do not confuse an MTA with programs like Evolution or Thunderbird which are MUAs (Mail User Agent): programs that offer an interface to a human to write email.

Nullmailer is one of those packages that create a “well duh” moment when you find out about it. Normally, hosts with no MTA can’t send mail, which turns out to be a Bad Thing in terms of finding out when things like cron jobs break, or for monitoring logs or files. So you go and install a minimal system, then wonder why it’s being so quiet. Well, no MTA, no email. But Exim, Postfix or another full MTA is overkill and might be tedious to maintain. What you really need is just a basic MTA to send messages to the real mail server.

That’s nullmailer.

The package will prompt for your remote mail server and create /etc/nullmailer/remotes, where you can also specify authentication details. You probably also want to create /etc/nullmailer/adminaddr to receive in one mail account all mail destined to your local host. Each file is a oneliner that contains pretty much what you’d expect:

$ cat /etc/nullmailer/adminaddr
I_get_roots_mail@example.com

$ cat /etc/nullmailer/remotes
mail.example.com

There are also several other files that may be used by nullmailer: /etc/nullmailer/defaultdomain and /etc/nullmailer/defaulthost in case you don’t already have /etc/mailname. For a complete list of control files, see the nullmailer(7) man page. Detailed information can be found in the man pages for each part of nullmailer: nullmailer-queue(8), nullmailer-inject(1), and nullmailer-send(8).

Pros:

• Simple.
• Just Works.
• Avoids the configuration, maintenance, memory footprint, and larger attack surface of a full MTA.

Cons:

• Configuration is scattered about in multiple one-line files instead of just a trivial config file.
• Documentation is a also bit scattered.
• The package might be a little more helpful by asking more questions when it’s installed (e.g. prompting for root’s mail recipient).
• Doesn’t provide the -bs switch, so it’s not LSB compatible.
• Gets very chatty in your log files when it can’t connect to the remote mail server.

Other alternatives:

• ssmtp - extremely simple MTA to get mail off the system to a mail hub
• http://linuxmafia.com/faq/Mail/nullmailers.html
• http://www.davidgrant.ca/ssmtp_vs_postfix_no_contest

Nullmailer has been available in Debian at least since Etch, and in Ubuntu Universe since Dapper.

Oops, this article was supposed to go live on Sunday, my bad.

Article submitted by Paul Wise. DebADay needs you more than ever! Please submit good articles about software you like!

Chromium B.S.U. is a top down fast paced high action scrolling space shooter. In this game you are the captain of the cargo ship Chromium B.S.U., and responsible for delivering supplies to the troops on the front line. Your ship has a small fleet of robotic fighters which you control from the relative safety of the Chromium vessel.

You control the robotic fighters with your mouse and repel wave after wave of different kinds of enemy ships. Launch Chromium B.S.U. from the Applications / Games / Arcade menu and start a new game. You will soon be sending volleys of weapon fire toward the enemy ships while protecting yourself with super shields, waiting for powerups to get closer or dodging fire from the larger enemy ships at the end of each level:

If you keep getting killed, quitcher whinin’, you ninny! It’s supposed to be hard! Seriously, Chromium B.S.U. is intended to be a 15 minute adrenaline rush/mental cleanser. Frequent doses of explosions can be very therapeutic. There is always kamikaze attacks or the BIG RED BUTTON if you get into particularly nasty trouble.

The chromium package is in Debian since lenny and Ubuntu since dapper, but it has been recently renamed to chromium-bsu. Chromium B.S.U. is an old favourite of the Linux gaming community that has been neglected until recently. The project is still looking for developers, especially to help move it off obsolete libs like libglpng and fix the rest of the bugs.

The chromium package has been available .

The chromium-bsu package has been available .

Article submitted by Paul Wise. DebADay needs you more than ever! Please submit good articles about software you like!

iotop is a console application for monitoring the I/O usage of processes on your system. It is especially handy for answering the question “Grrr, sloooowness, why is my disk churning so much?”

Just type iotop in your terminal and you will get a regularly updated list of processes and the amount of I/O they are currently using: reads and writesin bytes per second, and percentage of time spent swapping and waiting for I/O.

iotop is related to top and vmstat. In top you see a display of CPU and memory usage but not I/O. The vmstat utility shows it, but its just a stream of one-line reports instead of a dynamic display and doesn’t show the information in a per-process way.

Note that iotop needs the CONFIG_TASK_DELAY_ACCT and CONFIG_TASK_IO_ACCOUNTING options enabled in the kernel; in Debian stock kernels, that’s already the case.

iotop is available in Debian since Lenny and in Ubuntu (universe) since Intrepid.