>edfave at long last done a little more work on the mailserver project. The latest thing to report is the addition of dspam to filter out spam. In addition to this clamAV is also integrated.
The next step will be to do some more testing and then plug in another application which should make training and using the spam filter a little easier.
The documentation surrounding the addition of dspam and antivirus to the setup I am working on has been very hard to come by and in some cases is conflicting. Having made significant progress recently I am hoping to eventually have my setup production ready by the end of the year*. *Might as well give myself plenty of time.
Let me start by outlining the recent issues I have been having with electronic devices. Usually they behave as expected and under normal circumstances and change in this normal behaviour is easily recognisable. Problems occur however when multiple events coincide and reveal a change in behaviour or problem. Such an event recently occured; my previous post explained the issues I was having with Xorg Server. When updating my sever and power desktop I ran into an intermittant issue with sporadic keyboard lag. I initially attributed this to the usage of Synergy to share the keyboard and mouse between the server and desktop. The synergy setup used the linux server as the host sharing it’s keyboard and mouse with the Windows/Linux Dual boot desktop.
To diagnose the problem I booted the desktop into windows to make use the Logitech software to report on the battery status. This all checked out and the battery status was returned as ‘Good’ for both the keyboard and mouse. I proceeded to check several other options and recompiled software drivers. Stuggling to resolve the issue I returned to checking the Logitech utility, after giving the utility about 60 secs of run time it finally decided to report a low battery status. Replacing the batteries in both the keyboard and mouse solved the problems. It was another complete coincidence that the batteries in both the mouse and keyboard had failed at the same time. The peripherals had been purchased years apart with the batteries previously replaced in the keyboard only once and the mouse still using the same set from new.
On to the next battery failure now this one was partly down to human error. Whilst trying to use a laptop in the field I discovered that I had not packed the power supply. This resulted in a mild panic on my part due the urgent need to complete the task at hand. The laptop itself was a few years old and still running Windows 2000. Given the fact that it had been on constant charge when used the previous day the reason for my panic was the battery reporting 25 minutes run time after booting. With the requirement to have to carry out work, shut down, reboot and carry on working I had to be quick. In the end I took brief yet complete notes from which I could complete the rest later. That concludes the next battery issue.
After the current spate of battery problems the last thing I needed when returning to work was to find the batteries in the wireless mouse were dead. I don’t know what it was about the last few weeks but it seems that the battery population must be somewhat reduced. That reminds me, its time to buy some more AA batteries. You never know when the next device will fail.
Recently when applying the updates to my Gentoo Linux machines a new version of Xorg-Server was presented. Normally package updates are straight forward, this one on the other hand needed a big change in drivers and config files. My main issue with the upgrade is the poor upgrade documentation, there is a lack of detail surrounding the conversion of the old config file into the new config file. Now I can see the reasoning behind the change in config file syntax, it now provides fine grained control of options on a per device basis whilst allowing for common options to be applied to mutiple devices.
I found myself booting one of my laptops and discovering the keyboard and mouse wouldn’t work. This meant I could not login and change the config files. My way around this was to boot into a rescue shell, disable the xdm service running the graphical login screen and editing the config file from the command line where the keyboard worked.
My second laptop was not as much trouble but proved a little tricky by insisting on giving me a US English keyboard layout instead of GB English. This was partly my fault in that I had had missed out a set of quotes on one line of the new config file. I discovered that if a set of attributes were added to the section of the config that dealt with my mouse and they were not recognised it would not process the entire file resulting in the correct keyboard settings not being processed. This leads me back to my initial problems with the quality of the upgrade documentation not outlining common issues.
Lets get on to another issue now, getting my mouse buttons to work, previously I had specified some options in the old config to remap the forward and back buttons onto the hozizontal movement of the scroll wheel. The upgrade documentation lead me to believe I could transfer the options across to the new config, but this lead to the problem I described previously with the options not being recognised. Instead I have had to specify my button map in the .Xmodmap file in my home directory. In someways its a better place to put it but it would have been handy if the upgrade guide had given me a pointer that this was the way to achieve the result.
I now have 1 of my 4 machines fully upgraded, the rest can wait until the weekend.
In my efforts to add spam and virus filtering to my mailserver project I needed to have a hardcopy of a man page. Whilst it is possible to forward the output to a file “man [command] > outputfile” or directly to the printer “man [command] | lpr” neither option is perfect. Directing the output to a file leaves extra characters in the output making the text a little unreadable in places. Directing the output directly to the printer uses a font which is over large and a waste of paper.
The trick is to use the ‘-t’ option for the man command. This reformats the the man page with groff and sends the output to stdout as normal. The reformatted page is in Postscript format (looks a little odd when viewed on screen) which can be directly sent to the printer. The result is a nicely formatted printout with page numbers.
The entire command is:
man -t <command> | lpr
Replace with the name of the application/feature you wish to view information for.
After spending much time and effort on the mailserver project I think I have finally created a secure and working basic setup. It’s currently a little to late to do extensive testing but the brief tests carried out so far look good. A laptop with a self signed ssl certificate can securely connect to the mailserver over the local lan and retrieve the email in the imap store and securely send email out again. Trying to use the mail client on the mailserver itself correctly fails to retrieve the imap store or send email due to not having a self signed certificate to send.
If the rest of my tests work out in a similar manner and the services run stable for a week or so I might finally be able to declare the first stage of the project complete and finish off the documenting the process upto this point.
I was hoping to begin this month with news that my mailserver project was reaching the milestone objective of being secure and working, alas it is not to be. The good news is that over the past month I have made significant progress and am in the final stages of securing and testing.
I have dovecot and postfix talking to each other and maildrop filtering the incomming mail. Work at the moment is partly on documenting my decisions and testing processes and partly on implementing the remote authentication over a secure link. I am taking the security aspect quite seriously and as a result it requires extra time to get it right. Currently my documentation/notes are upto 30+ pages in openoffice and I may even split the guide into sections. The SSL certificate generation and usage notes I have been making are quite extensive and can be used to generate self-signed certificates for other applications too.
Fingers crossed another month might be all I need; only time will tell.
Driving home this evening down a dark country lane at a reasonable velocity I discovered some weaker members of the species. The weaker links in a species should be allowed to assist the species as a whole by removing themselves from the genepool. This usually involves their own stupidity leading to their own demise.
The event in question featured 2 cyclists and a pedestrian. Cyclists in recent years seem to have decided that a tiny flashing or constant LED array smaller than a playing card sufficient to indicate their presence on the road rather than a larger bulb based light. This is fine for reducing the overall weight and handling of thier chosen method of transportation; however on the other side of a blind bend its only effect is a brief blur as its rider slides over the roof of the car. It was lucky then that I spotted the 2 cyclists pushing their little LEDs along the road. Clad in dark colours the LEDs were the only things visible. Now it is difficult to see them and their going at walking pace and being hit by a motor vehicle might be a little uncomfortable for them. Walkers in a similar situation would be on the other side of the road looking for oncomming traffic and being ready to launch themselves into the nearest hedge should events take a turn for the worst, but not the travellers tonight.
I think I have established the stupidity of the cyclists pushing poorly lit bikes along in the dark without high visibility clothing but I have neglected the pedestrian with them. If I were to be in a situation where a motorist may not see me I would be sure to make sure I was out of the way at the side of the road. The primary candidate for elimination from the species was to be found walking down the middle of the road, back towards the traffic without any illumination talking to one of the dismounted cyclists.
I could have assisted the human race by removing a weak link, but apparently the law says I should leave them be. Calling it an accident is not a way around it either, I would be found guilty of causing them harm. For some strange reason the stupid have more rights than the sensible. If they don’t want to come to harm they should not be in a position to be harmed and those too stupid to realise danger are of no use to society as a whole. Society just ends up breeding lemmings. Which raises the question of “How do we point them to the nearest cliff?”
It’s unfortunate that my first post in 2009 has to be on this sad topic but I guess it has been on the cards for a few weeks now. The nice twice/thrice weekly tech update presented by Morgan Webb has come to an end. This means her smilling face will be missing from the main page of this site in future. The reason according to webbalert.com is that Morgan has more pressing regular commitments and does not have the time to dedicate to this project. It is certainly a shame and you will be missed. A few minutes of condensed tech news allowed me and others to keep up to speed on world tech happenings. There doesn’t appear to be an alternative at the moment .
I hope everybody out there who has at some point watched WebbAlert joins me in wishing Morgan all the success in her future projects.
In the past few weeks I purchased some new Anti-virus and Firewall software from ESET to replace my expiring & bloated AVG install. The first machine to get the upgrade was my XP desktop machine; everything went well. I was impressed with the lighter feel to the software and the added fact that it didn’t seem to be hogging the system resources quite as much. A weeks trial later I decided it was stable and usable enough to be used on my laptop; running Windows Vista. The install was painless and the software scanned my system and there were no obvious issues.
The problems arose when I came to reboot the machine following some windows updates and some minor web application updates. Read the rest of this entry »
Well it’s that time of year again; the time the wallet starts to strain as money is removed from it. To ease myself into the spending spree which will happen over the next few weeks I have treated myself to a Gigabit Switch and a toner cartridge. They may not be exciting items for most people but I feel I need them. I was also feeling the need for another 24″ monitor but the reviews of the intended model have put me off for the moment.
All I have ton do now is put my feet up and wait for things to arrive.
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