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While searching for an easy way to do server side Spam filtering, so I don’t have to bear with all those spams when looking at my Inbox with Webmail, I found IMAP Spam begone. It’s a python script that scans your Inbox for new messages and hands them to Spamassasin to check their spam status and copies them to a pre-defined folder in your Maildir if it is found to be a spam message. Client side spam filtering is done with Apple Mail on my iBook which works very good for me. So there is a second layer of filtering in place in case something still gets through.

Although isbg.py is rather old and hasn’t been updatet in about three years it works very conveniently and tags nearly all of my Spams, moves them to my Junk folder and deletes them from my Inbox. The script is called from a cronjob and run every 10 minutes so there is a slight chance that I still find Spams in my Webmail before isbg.py is able to run and delete them.

The reason I settled for this “external” integration of Spamassasin via isbg.py is that I didn’t want to mess around with the transport rules of my MTA because of the chance to do something not all users are happy with. With IMAP Spam begone I have an individual solution that works for me without altering the way all the other people experience the mail service.

Below you’ll find the command line options I have running, for further explanations please refer to the projects homepage.

isbg.py --spaminbox INBOX.Junk --spamc --delete --nostats --expunge

Update: Since the ISBG site seems to be down currently, I’ll provide a download link for the script here.

isbg.py

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Because I searched for it now for half an hour and could only find it in the Google cache.

Irssi proxy usage:

First you’ll need to have the proxy module installed, either configure
irssi with –with-proxy and do make install, or manually:

cd src/irc/proxy
make
mkdir ~/.irssi/modules
cp .libs/libproxy.so ~/.irssi/modules/

In irssi, say:

/LOAD proxy

You really should set some password for the proxy with:

/SET irssiproxy_password secret

Then you’ll need to configure the ports/ircnets the proxy listens in, something like:

/SET irssiproxy_ports ircnet=2777 efnet=2778 freenode=2779

There we have 3 different irc networks answering in 3 ports. Note that you’ll have to make the correct /IRCNET ADD and /SERVER ADD commands to make it work properly.

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Tunnelblick

A few month ago I started to look at OpenVPN which has a very good GUI for the Mac called “Tunnelblick“. After I managed to set it up on my server I thought why not share my home directory via the VPN tunnel and mount it on my Desktop. It should be fairly usable, providet I’ve got sufficient net connection on my end, since my server has a 100MBit internet line. So I set up Samba and let it listen only on the VPN interface.
The following is a quick step-by-step how-to on setting up such a setup 🙂

Install OpenVPN on your server
Donwload the latest source from http://openvpn.net/download.html
Unpack it and run the usual commands:
./configure
make
make install
Then do some testing:
make check
If it all works fine, you’re good to go.
The other possibility is of course to install it from a package your distribution provides you, in my case this is handled by apt (aptitude install openvpn) which has the advantage of setting up init scripts so the VPN is startet at system boot and taking care that the whole environment on the server is suitable.

Configure OpenVPN on your server
We’re gonna work with a pre shared static key here because it is easier to set up and provides enough security for home use.
My config file on the server side looks as simple as following (/etc/openvpn/home.conf):
dev tun
ifconfig 10.8.0.1 10.8.0.2
secret static.key
comp-lzo
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
This tells OpenVPN to start a new VPN on the “tun” device with the IP of 10.8.0.1 using the key named “static.key”. The rest are some tweaking commands which should be pretty self explanatory.

Now we only need the static key.
We can construct one by putting in the following command:
openvpn --genkey --secret static.key
The static key file is formated in ASCII and should be kept very private. Send one copy to the computer you would like to connect to your server and keep the other copy besides your config file on your server.

Install and set-up Samba
Next you need to install Samba. I again took the Debian way via “aptitude install samba”. Then I tweaked the standard setup to export the user’s home directories and listen only on the VPN interface and not the normal one.
interfaces = lo, 10.0.0.0/8
bind interfaces only = Yes

[homes]
comment = Home Directories
browseable = yes
writable = yes
create mask = 0775
directory mask = 0775

The rest of the smb.conf file can be pretty much left alone.

Start openvpn and samba
Provided you installed it via your packaging system or set up the init scripts yourself you can now start the two programs by typing in “/etc/init.d/openvpn start” and “/etc/init.d/samba start” (or wherever your distri keeps it’s init scripts).
If the two started up ok, you’re done on the server side.
Time to move on to the client.

Install Tunnelblick
Download it from www.tunnelblick.net, mount the Disk Image and double click on “Tunnelblick-Complete.mpkg” which installs all the necessary drivers and software packages. Now you should have a Tunnelblick icon in your Applications folder.
When starting the program for the first time, it will well you that there is no configuration file present and will offer you a sample configuration.
Simply replace the sample configuration with the following:
remote IP_OR_DOMAIN_OF_YOUR_SERVER
dev tun
ifconfig 10.8.0.2 10.8.0.1
secret static.key
comp-lzo
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
As the last step you have to put the file “static.key” that you obtained from your server earlier in ~/Library/openvpn (this is where your config resides as well).
This should be it. Click on the Tunnel entrance symbol to the left of your Spotlight icon and choose your config, after a short moment the connection will be present.

The last thing to do is to mount your home directory.
Press CMD+K in the Finder (or go to “Go -> Connect to Server” in the Menu) and type in the following:
smb://user@10.8.0.1/user
substituting “user” with your username on the server. After that a new icon should appear on your desktop containing all the files you have in your home directory on your server 🙂

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MotionI recently installed a simple video surveillance system at a facility I work.

The main goal is to know who (and when) entered our server room. Currently the setup features a tiny Philips USB cam connected to a Linux server (running Debian Sarge). At a later Stage this webcam will be replaced by a proper network camera (or even several cameras).

The software I used is called Motion – a relatively easy to set up video surveillance system that does motion detection (…and much, much more). Motion detection is ideal for my purpose because the room is normally completely dark unless somebody enters it and switches on the light.

Now every time somebody comes in, a short video is produced and saved on our server. I made a web accessible filesystem alias to the video directory, so I could check whether there was new footage available. This process was not automated enough for me, so I slapped together a short (und ugly) PHP script that takes the contents of the video directory and delivers it as a RSS feed that I can now subscribe to with my news reader.

The script is available at the Motion WIKI and can also be downloaded from there.

[Update:]
Some photos of the former chaos in our server room and it’s extinction can be viewed here.

special thanks to Herbert for having the idea 😉