Strangeparty » Technology

Frequently Asked Questions about the GNU GPL

Anton Piatek — Thu, 08 Dec 2011 11:18:45 +0000

I have been flicking through the following FAQ on the GNU GPL: Frequently Asked Questions about the GNU GPL – GNU Project – Free Software Foundation (FSF). I am trying to understand the risks that we are told about regularly in IBM of working with/on Open Source code.

I have to say that most of the risks are rather undefined, and no real examples are given. I am having trouble figuring out why IBM is so scared of its employees working with Open Source, and yet at the same time encouraging it (I run Debian on my laptop, and in fact run a Debian server distributing internal tools packaged specially for other Debian users).

The one big concern is of course patents. Personal views on software patents aside, if I were to code a patented idea into some GPL’d code and release it (as an IBM employee) then quite likely that patent will be considered GPL’d and could be used by others – the extent of patents in GPL’d code is untested in court, hence the reason for v3 of the GPL, which will probably explicitly state that any patents are given away under the terms of the GPL if in GPL’d code.

However, even if not modifying the code there is still a huge concern about working with it. Even releasing code that is dynamically linked against a LGPL’d library is incredibly hard to get approved. Why should it be? The FAQ above makes clear that if the library is LGPL’d, then dynamic linking (i.e. using a JAR file in Java) means that the library source must be available and some reverse engineering of the interaction between the two is allowed (in case someone wanted to rewrite the library). Your code does not have to be Open Sourced. Is it simply that shipping the source code is too much effort? Surely if I use a prebuilt JAR, and dump a zip of the corresponding source of a LGPL’d library in the zip I am shipping then that is it. I am complying with the terms of the GPL.

The only thing I can think of is the other side of Patents – somebody else has a patent on something in the GPL code, but the authors of the GPL code were not aware of this. If IBM were to ship GPL’d code that a competitor had a Patent on part of then indeed they would be liable for infringement, not just the author of the code. Is this risk likely? Well, SuSE have just signed a deal with Microsoft for this reason, but RedHat and Ubuntu have declined the deal. Maybe with the GPLv3 this will be less of a problem, as if another company releases GPL code then they will be explicitely releasing any patents on it too.

What if the patent holder is another third party. IBM could still be in trouble if a competitor finds they have a patent on some GPL’d code we are shipping. They won’t bother suing small linux vendors, but IBM has lots of money to claim from, that would be worth going to court for. Could they claim only for IBM and not all the little guys who have already been using it?

Is it too much risk to work on the fact that we could always change the code to avoid the patent at a later date?

Kindle-ing a desire to read

Anton Piatek — Wed, 07 Dec 2011 14:12:56 +0000

This post was originally drafted in May when I actually bought my kindle – I finally got round to actually publishing it…

Earlier this year I finally gave in. I felt a moment of regret about buying into an enormous DRM machine as I clicked purchase on my new Amazon Kindle 3G. I felt a little dirty because of the DRM. Still, I wasn’t buying Sony so I can live with it.

Then theft next day it arrived. So simply packaged, entirely in recycled cardboard, that I forgot about that dirty DRM feeling and tore open the packaging. I pulled out my new kindle and just sat there admiring the instructions showing on the screen. A screen which could show that image for months without charging. It was beautiful.

DRM aside the kindle is an incredible thing.

There are a few hiddenkindle gems including shortcut keys, minesweeper and how to change the screensaver pictures at the following site: From down the hill : Kindle 3 Keyboard Shortcuts et al.

Since then I have been averaging just over a book a month. Some were free, some were £0.71, most are around the £5/£6 mark and one was nearly £10. DRM aside, I have been reading way more than I normally do, as getting to the end of a book is not such an obstacle. The hardest part is choosing what to read next, but while in the middle of a series it is only a 15 second delay to get on to the next book.

I am looking forward to UK lending and eLibraries which support Kindle. Though even without that, I am still reading more than I ever used to and am really loving the fact that I have so much available to read with so little effort. In some ways it is slightly worrying how easy it is to purchase a new book, but at least they are generally cheap.

Upgrading cyanogenmod

Anton Piatek — Mon, 05 Dec 2011 13:48:00 +0000

I previously wrote about rooting a HTC Desire and installing CyanogenMod 7. A month or so ago, a new CyanogenMod rom was released, and I finally found the time to upgrade it.

Of course I first did a full backup, as described in my previous post, using the recover mod.

I first tried updating the rom via RomManager, which is apparently the preferred way to upgrade CyangonMod roms. Updating the Clockwork Recovery Mod went fine, and the app allows very easy downloading of alternate roms, however actually intalling did not go so well. It failed due to some error in the upgrade script. I decided to simply report the error and move on to a manual upgrade.

Manually updating was pretty much the same as installing the roms in my previous post. Using the reovery mod I installed the new Rom from the zip which was downloaded via RomManager, followed by the Google Aps zip. Then I cleared the Dalvik cache, as I wasnt sure if it would interfere (it doesn’t hurt to clear it anyway).

The update was quite smooth, and after a reboot or two nearly everything was working as before, though it took a while for all the app icons to come back on my desktops. As I did not reset any application data I did not have to reinstall any of my apps or restore the data.

The only issue I found is that the calendar would crash upon starting. I installed CatLog, which allows you to view the android system logs, and very quickly found a stack trace from the calendar app saying it could not find a database column.

I guessed that the storage format must have changed, and as it is all synced from my Google calendar anyway, I thought I would just clear the data and let it resync. Under System->Applications I found the app CalendarStorage, and simply deleted all its data. After a moment to resync from the cloud, everything looks fine.

The latest CyanogenMod 7.1 seems to have some fixes I have been waiting for. In particular, I quite liked the dual lockscreen. A shorter timeout for a swype unlock, where the lockscreen has a music widget. The longer timeout is the unlock pattern. This was not possible in the older CyanogenMod 7.0.3 as a bug seemed to only show the pattern unlock screen.

There is quite a list of new fixes, but I don’t think I needed any of them. One new thing I noticed is that holding down the power button gives not only the usual shutdown/reboot options, but also a screenshot option, which is quite useful and removes the need for a separate app to do this.

Guest presenting on the Ubuntu UK PodCast

Anton Piatek — Wed, 28 Sep 2011 20:41:00 +0000

I was a guest presenter on this weeks Ubuntu UK PodCast. I talked about Southackton, and IBM’s use of Ubuntu on the desktop.
Listen to the podcast at
http://t.co/vVL5M3YJ

Rooting and upgrading a HTC Desire to android 2.3 (CyanogenMod 7)

Anton Piatek — Thu, 23 Jun 2011 20:20:28 +0000

I started writing this as I was actually doing this to my phone. The problem I found with most existing instructions is they seem to slightly contradict other instructions you find. Many have steps which are not well laid out and often don’t give a reason for doing things which can be a bit annoying. Often the instructions are from ancient Android OS version days, so steps like installing hboot versions, and recovery roms are now all covered with the one unrevoked3 step, but not all instructions are clear that this is the case.

These instructions are heavily based on the instructions from CyanogenMod 7 for HTC Desire: http://wiki.cyanogenmod.com/wiki/HTC_Desire_(GSM):_Full_Update_Guide but also some other sites I found along the way, often for other phone models so only parts apply. I also had some direct feedback from various IRC channels.

The following links were useful to me, so I mention in case you want to read some more:
http://forum.xda-developers.com/forumdisplay.php?f=628
http://forum.xda-developers.com/showthread.php?s=ea2964d1e59f99d394ca758037ee6bc1&t=696189
http://forum.xda-developers.com/showthread.php?t=788044

1. Preparations

The first thing that may be of use, especially if you are checking other instructions, is to grab a few version numbers of the rom levels on your phone:

power off, hold vol down and power – get hboot version page, includes radio version
mine was hboot 0.93.0001
and my radio version is 5.11.05.27
hboot version shouln’t matter for unrevoked3 though unless on very new phone like EVO4
You can also check the radio version from “Settings->About Phone->Software information”.
You should see “Basebane version”, mine is 32.49.00.32U_5.11.05.27
The last part of that, after the _, is the radio rom version

2. Rooting your phone

Go to http://unrevoked.com/recovery/ and download the rooting program.

This uses an exploit in the phone to install a new recovery rom, the “clockwork recovery” rom, which can then be used to do complete phone backups and install new roms.

You will need the “usb debugging” enabled on the phone, and the phone connected only to charge, not as disk access or tethering

It is straight forward on linux (run the downloaded file, and follow the instructions on screen), but I believe on windows there are soe extra drivers to install so check the unrevoked site for more instructions if you are on windows. .

I tried unrevoked3 with only 14mb available, and got “internal error: installing package failed”. Getting the space up to 25mb and it worked fine (I just uninstalled the gmail updates)

3. Backup your current OS (nandroid backup)

Reboot into the hboot screen as in step 1 for version numbers, then use use vol up/down to select “recovery”. The power button acts as the “ok” button here.

This boots the clockwork recovery rom which was installed when you ran unrevoked.

Then use trackball to select backup.

This does a complete backup to SD, also referrred to as a “nandroid backup” which should include the system OS, all installed apps and user data.
You probably need as much space as your phone has on internal memory (512mb for desire).
This will take a little while, so do it on power or a full battery.

The backup should appear in your sdcard in /sdcard/clokworkmod/backups/

Then press back and select the reboot option.

4. Backup apps and app data for migration

Why do you need this if you just did a complete backup? Well, when you install the new OS you will be erasing everything from the internal memory, so this backs up your apps so you can install them again, and also the app-data so you don’t lose it all.

I used the free version of “Titanium Backup” but “Astro File manager” has been suggested too, and it looks like “Gemini App manager” can do this as well.
It is pretty straightforward, but see http://www.incredibleforum.com/forum/htc-incredible-hacks/7893-titanium-backup-how.html if you want specific steps.

5. Backup your whole SD card

Ok, maybe I am paranoid, but at this point I plugged in my phone via USB and zipped up the entire SD card onto my computer. This way I have a backup of my SD card, which includes all the above backups, so if anything goes badly wrong I still have the restore files

I had to disable the usb debug mode to get the disk to mount

6. Update radio rom

Before applying the cyanogenmod, or any other, you may need to update your radio rom version.

According to http://wiki.cyanogenmod.com/wiki/HTC_Desire_(GSM):_Full_Update_Guide the version of mine is good enough for CM7, so I didn’t update it.

7. Now install new rom

Installing the mod is straightfowrard (there are instructions in the first link of this page).

Basically download the mod, and google apps if you want it, and drop the zip files in the root folder of the SD card.
Then use the clockwork recovery mod as we did earlier and select “Wipe data/factory reset” to clear the flash (I have seen reports that this may not be required, but as it is such a large change of version numbers, I decided to do a full wipe), then “Wipe cache partition” to clear that too.

Then simply select “install zip from SD card” and install the new mod, and google apps if you wanted it.

Alternatively, you can use Rom Manager to do it as an app.

After the reboot, use your chosen backup program to then restore all your apps and data, however read the next step first as you may find space to still be an issue.

8. Space savings with CyanogenMod 7

After rebooting into the new OS, I had over 100mb free for base image (out of 148mb capacity reported by OS). 83mb free after installing a similar set of google apps from the market.

After then restoring all my backed up apps and data I found out I only had 25mb free, which is only about 10mb better than on the original android 2.2 from HTC.

You will probably find you have to install an app to force apps to install on SD card by default. Note that CyanogenMod 7 has an option to force all apps there by default, but it will put apps with widgets on there, which breaks the widgets.

There is a way to get even more space for apps with CM7:

All you have to do is add an ext4 partition to your SD card and then install “simple2ext” from the android market.

This is a feature only available on the CyanogenMod 7 roms, and allows you to move all apps, app data, and caches to SD card. There is a performance hit for this, but it seems worth it.

I used a microSD adapter to plug in my SD card into my PC and used “gparted” on Ubuntu (a Live CD will do fine) to shrink the current partition and add an ext4 one
without losing data (but you backed up above in any case, right?)

I created a 1GB partition and after installing simple2ext, I set it to move my apps and dalvik cache to the ext4 partition.

After a reboot I now have loads of space for apps to install to, about 80mb free despite installing another dozen apps without bothering to move them to SD.

To help you decide what to move, the Dalvik cache appears to be a binary cache for the Android implementation of Java. There is a performance hit to moving anything to SD unless you have quite a fast card (http://forum.xda-developers.com/showthread.php?t=1175707 recommends minimum class 4, better yet a class 6). Mine is class 2, and I found that moving the application data seems to
cause the phone to be very noticably slower, so it is probably best avoided unless you have a fast SD card.

Moving the Davlik cache did slow things down a little, but mostly only the boot time and first launch of an app. I decided that for an extra 80mb of space that I could live with that (I have also just ordered a new class 6 SD card, so that should help).

Conclusions

Rooting, and modding was actually incredibly simple. It sounds so scary, but I think it is actually very, very hard to mess it up to a point where you cannot just overwrite with a new mod (or your backup) and start again. Once you get to the nandoid backup point you have a very good recovery strategy!

I have loads more space, which is good, because counting the bytes is annoying. I now don’t have to worry about if I have space to install something.

You do lose the HTC apps and widgets, but I found I could live without them fairly easily (I haven’t used peep since I discovered TweetDeck, and that was my most used HTC app). If you miss the clock widget, search for “sense analog glass clock” on the android market, that is a nice replacement for me. “glass widgets” is a replacement calendar widget, which I now actually prefer.

The battery manager in the new rom is awesome compared to the old 2.2 one. It really shows where the battery is going. I think I possibly get longer battery life with this rom too.

I much prefer the android 2.3 native keyboard to the HTC sense one.

There are some niggles – I have a few gui glitches which cause me to reboot the phone every few weeks, but I am hoping they will be fixed in the next stable build (I have not been brave enough to try the nightly builds :-s )

Overall, I quite like the new UI though it did take some getting used to. The fact I dont have to worry about space is the biggest reason I will keep this rom, though it does sound like starburst rom which is much closer to vanilla HTC sense branded android also allows the “data2sd” hack to get more space

Arduino talking to an I2C LCD display

Anton Piatek — Mon, 17 Jan 2011 19:33:05 +0000

I had a spare Matrix Orbital 20×4 character LCD floating about so I decided to try and connect it up to my Arduino. The display is a LK204-25, which is a brilliant little serial display, with support for a 25 button keypad and six outputs that can be used to control power to something else.

Being a serial display, I could just write to it from my Arduino using the serial interface, but that would mean that I lose the ability to communicate with my Arduino from my computer over serial. Fortunately the display also supports I2C as an interface (some similar, but newer, models also contain a 1-wire interface and a temperature sensor built in).

It turns out that getting the display to work with my Aruino Uni, using I2C is rather trivial. The display needs power, that is easy enough, and then there are just two wires to connect from the Arduino – Analog pin 4 for is SDA, analog pin 5 is SCL. Connect those two up to the display (the display docs show which pins SDA and SCL are) and you are ready to write the code to control it.

It turns out that I2C has fantastic support in Arduino, Wire.h contains all you need. The code below will read a character from the serial connection from your computer and write it to the display. Easy, eh?

// Note the space after the . in the imports below - This blog seems to object to not having it there
#include < wire.h>
// default MatrixOrbital lcd address (0x5C) converted from 8bit to 7bit
#define LCD (0x2E) 
 
void setup() {
  Serial.begin(9600);
  Wire.begin();
 
  // Initialise display with clear command
  Wire.beginTransmission(LCD);
  Wire.send(254);
  Wire.send(88);
  Wire.endTransmission();
}
 
void loop() {
  if (Serial.available() > 0) {
    char c = Serial.read();
    Serial.write(c);
    Wire.beginTransmission(LCD);
    Wire.send(c);
    Wire.endTransmission();
  }
}

Who came up with eBook pricing

Anton Piatek — Sat, 07 Aug 2010 10:34:09 +0000

Seriously… Who decided how to price eBooks?

A friend at work recently recommended I read Richard Morgan’s Altered Carbon. The Kindle app on android allowed me to find it quickly and download the first 3 chapters free to read – I loved it and decided I wanted to read the rest of it… However when checking the prices I was left the feeling that eBooks are just too expensive for what they are

Play.com £5.99
Amazon UK £5.19
Kindle (Amazon UK) £4.88

I went with Play as their free delivery normally takes about 2 days, so that was great. But seriously, nearly the same price for Kindle? For a book I cannot resell, lend or give away?

Digital books should be much, much cheaper – There is no printing cost involved, so the book should be significantly cheaper, but this is not what I am seeing.

If I choose to keep the book and reread it again in a few years, the price may be fine. But I am more likely to read it once, and then give it to a friend to read. Why should i pay nearly the same price for something I cannot lend, sell, or give to a charity shop?

Also, how on earth does a paper book qualify for no VAT, yet as soon as that book has no paper involved I have to pay VAT?!?

There are lots of Kindle books for £3 or less, and for these I will probably just buy it digitally as its incredibly cheap. But if I wanted to buy a recent release, then I really am paying a lot more for a digital book just to have it early? Why?
I can understand pricing getting lower for older books as they have to compete with people lending books, libraries and second-hand sales, however none of that is possible for DRM protected eBooks, so they should all be priced the same as older releases

App Inventor for Android

Anton Piatek — Mon, 26 Jul 2010 07:41:20 +0000

Saw this recently on the Google blog:

App Inventor is a new tool in Google Labs that makes it easy for anyone—programmers and non-programmers, professionals and students—to create mobile applications for Android-powered devices. And today, we’re extending invitations to the general public.

via Official Google Blog: App Inventor for Android.

It looks really cool, and allows really quick generation of apps via a gui interface which is powered by MIT’s Open Blocks framework which sounds like a really cool way to get children and students into programming

I can’t wait to get my invite to try it out!

eBooks on Android

Anton Piatek — Fri, 23 Jul 2010 18:29:37 +0000

Since buying an Android phone I have been starting to think about using it to read books. The screen isn’t bad, and it turns out that there is some good software out there

Aldiko is a fantastic program for reading free ePub books, so I am working my way through a few H. G. Wells books as they are now public domain and available directly through the program (along with many other free books). The software has good options for font styling, line spacing, page turning, black on white vs. white on black as well as quick shortcuts for changing the brightness.

One thing I have yet to figure out though, is buying eBooks.

Sure, there are loads of places out there that sell them, many including their own software (available for Android) for reading the books with DRM. However it is almost impossible to work out which ones use which DRM systems, and what the restrictions are on them (some may even be per-book)

Why am I worried about DRM? Well, what if I want to read the book on a train on a laptop, or what if my phone dies and I get a different phone? Can I transfer it to another device? What if I decide to buy a hardware eBook reader? Will I be able to copy my books to it and read them there?

I haven’t even addressed the idea of lending the book to my wife without giving her my phone.

DRM worries me greatly, and so I doubt I will buy an eBook anytime soon unless it comes without DRM (but no sites make it very clear that they are DRM-free). Why can’t they come to the same conclusions as online music distributors and realise that DRM-free means more sales?

I guess it is paper books for the forseeeable future

Ubuntu in Business

Anton Piatek — Thu, 15 Jul 2010 14:33:01 +0000

On Tuesday I attended the Ubuntu in Business event run by the Ubuntu UK Community and Canonical, and unlike Proactive Paul I really enjoyed the day and thought it was a success.

I will agree and say that there should have been more introductory talks on Ubuntu and Open Source for those people that were not familiar, especially as they were trying to target new and potential users, however given half the audience was already running Ubuntu I am not sure if that would have been a waste. Certainly introduction demo’s are always good and especially for someone new to Ubuntu or Linux this would show that really it is not very different from using windows and is certainly not scary!

The talks and targetted demo’s were good, in particular I was curious about the Ubuntu Cloud and Landscape which both seem really good. For me the best part of the day was when the guest speakers and Canonical hosts got up on a panel and were interviewed by Glyn Moody which resulted in some fantastic discussion, excellent answers and some good questions and responses from the audience.

Of course the ubuntini cocktail afterwards was interesting too – not really my thing, but was nice to try.

The conversation after the cocktail was possibly the best part of the evening – actually getting to talk to some of the Canonical folks and forging a few new links. Some good conversations about IBM and Ubuntu, hopefully it won’t take too long for sanity to break-out and IBM to consider Ubuntu seriously
(If you are a business buying IBM software and want to use it on Ubuntu, make sure you tell your salesman this – If IBM doesn’t hear people asking for software on Ubuntu then there is no reason to ship it for Ubuntu).

Running a personal server

Anton Piatek — Sun, 27 Jun 2010 18:18:00 +0000

Maybe you read some of my posts on software raid and lvm, or maybe you have a spare pc lying around and want a box you can use as a small personal server and are wondering about some tips for running it with less hassle. I am sharing a few things that I have learnt about running a personal server (though some will apply to any Linux server or always-on machine) that make my life as a part-time admin easier. This is by no means an exhaustive list, nor necessarily the correct way to run a box, but it works well for me and so should be useful to others as well.

ADSL port forwarding

If your box is behind an ADSL modem (and unless you have a professional server and datacentre to put it in, it probably is) then by default the NAT addressing and firewall will mean that you cannot get in remotely to your box. This may be fine if you don’t want anything from the box accessible, but I tend to like being able to ssh in from anywhere, so you need to set up some port forwarding from your ADSL router/modem to get into your box

I wont attempt to describe how your ADSL modem/router config works, you’ll have to read it’s manual, but the ports you probably want are:

ssh 22 – if you want to log from outside your home network with ssh
smtp 25 – if you want your box to be able to receive email
ftp 21 – if you want ftp (though I recommend sftp or scp which use ssh and therefore encrypt your password and data)
http 80 – if you want webpages visible from the internet
https 443 – if you want webpages visible from the internet and want to use https encrypted http

Dynamic DNS

Unless you have a fixed IP address from your ISP, you will probably want some sort of Dynamic DNS system that sets a hostname to have your current IP address. I use http://dyndns.afraid.org as they are free, you can host your own domain there and there are plenty of domains you can use for sub-domains if you don’t want to buy a domain. They provide lots of scripts to help you keep your IP address recorded correctly whenever it changes

Mail

I really want mail configured for delivery, as that is one of the easiest ways to get alerts from your machine (though twitter could be cool too though). If you have a email to smms gateway or smartphone with push email then these alerts can be very fast and direct.

I use exim, not because it is the fastest or most configurable mail system available, but because it is very easy to get configured and running on Debian or Ubuntu. Simply install the exim4 package and the debconf wizard will get you up and running.

sudo aptitude install exim4

The wizard, which can be re-run with the command sudo dpkg-reconfigure exim4-config, asks you how you want to configure exim. Normally you select the first or second option (“internet site; mail is sent and received directly using SMTP” or “mail sent by smarthost; received via SMTP or fetchmail”). Most of the questions come with sensible defaults. If you selected the second option you will get asked what your smarthost for sending mail is, in many cases this is just mail.your.isp or you can use google if you have an account, but it will require authentication which which is a little more complicated to set up.

Next you want to set all email for ‘root’ to forward to you preferred email address.
Edit /root/.forward to look like this

# Exim filter   < <== do not edit or remove this line!

if error_message then finish endif

deliver me@myemail.com

You can test sending email with a simple command line of mail root -s test followed by a message and then CTRL+d. You should get the email at your address set above.

Logwatch

I like to know what is happening on my boxes, and logwatch does a great job at summarising the changes that have happened very day. Install logwatch with

sudo aptitude install logwatch

and it will email root every day with a summary of log changes and other useful info.

As I don’t actually want this information every day, I moved the cronjob for logwatch from daily to weekly with

sudo mv /etc/cron.daily/00logwatch /etc/cron.weekly/00logwatch

so now I get a weekly summary for my box, which is good enough for me

Raid emails

As I use software raid to make my disks a little more redundant (Warning: RAID is not a backup strategy. 2 disks CAN (and sod’s law / murphey’s law says that at the worst possible time they actually will) both die at the same time. RAID simply gives you an extra chance to get a new disk without having to get your data from a backup)

If you use software RAID, make sure your raid config
cat /etc/mdadm/mdadm.conf
has the following lines set appropriately

MAILADDR root
MAILFROM raid@myserver.com

Smart disk monitoring

As I don’t trust disks (and you shouldn’t either, as they will die on you at the most annoying time) I like to have the S.M.A.R.T disk monitoring installed, which does occasional tests on the disks, and can warn you if the disk starts showing bad sectors. If your disk does have bad sectors, it is probably best to replace it pretty soon, though sometimes you can just get a very small set of bad sectors and live with the disk for a long time.

Install smart with

sudo aptitude install smartmontools

and if you have logwatch installed too, then the SMART reports get added to your logwatch summaries (including disk temperatures which can be a good indication of airflow in your box)

Toughening SSH

I found that I had a lot of attempted logins on my box because SSH was open on the default port. One solution is to move the default port, but I am likely to forget to use that port number and just confuse myself… So I started looking at other ways to reduce the risk of having someone brute-force their way into an account.

You can use some really good stuff like fail2ban to take failed logins and firewall that IP off for a while, but I decided that I wanted something even stronger. I disabled password logins completely via SSH! To do this you will need to have created a ssh keypair and set up the public key on your server and make sure it works to log you in BEFORE you disable password logins.

To disable password logins, simply edit
/etc/ssh/sshd_config
and change

PasswordAuthentication yes

to say “no” instead. This will mean that you can never log in with a password, and have to use a ssh key. This will be almost impossible to brute-force, though you do have to keep your private ssh keyfile secure.

As a minimum, you may want to think about setting

PermitRootLogin no

in your sshd config so that the root account cannot be brute-forced, as this is probably the most common account that attempts are made on.

Monitoring with Munin

To keep an idea of how busy the box is, the cpu and ram usage, disk usage and many more things I have installed munin to monitor my servers. Munin logs system activity and automatically creates web-accessible charts of the status of your box. An example is online at http://munin.ping.uio.no/. I have set mine as password protected via an apache htaccess file with htpassword (there are plenty of resources online for how to do this), so that only I can see how busy my box is.

If you also install sensord and lm-sensors then munin can also chart things like fan speeds and temperatures

Security updates

Whether you are running Debian, Ubuntu or any other linux OS, make sure you check how to setup security updates for your distribution and install updates regularly. Having old packages is possibly the easiest way to get your box exploited.

If you don’t like having to remember to install packages you can install cron-apt to download the packages and tell you, so you can install them, or even install them for you (however it is generally a good idea to know what is going onto your system before it goes in, just in case anything looks suspicious or might break something)

/etc in revision control

Have you ever made a change to your system config, then realised not long later that it was a bad change, but can’t remember what you did?

Introducing etckeeper. etckeeper is a very clever package that takes /etc and puts it all in git. It can easily be configured to automatically commit every time you install or remove a package, so that all you have to do if you found something in /etc is broken is check the recent changes!

Simply install it with

sudo aptitude install etckeeper

and it pretty much works out of the box (It also supports other code control tools other than git, but the default is git)

Anything Else?

This list is by no means complete, and there are probably many more common tweaks you can do – Please leave a comment if you think of anything else that fits in or anything I might be doing wrong (hey, nobody’s perfect!) as I am always looking to improve how I run my little servers.

If you have several machines and static IP addresses then you can configure syslog to log to across the network, which would be cool as you could have errors logged from a box that has had bad disk crashes and dies and still know why. However I don’t have static IP’s so have not looked into this much

HTC Desire – Android rocks!

Anton Piatek — Wed, 09 Jun 2010 18:32:31 +0000

I gave in to the whole “smart phone” thing on the a week ago and ordered a HTC Desire online. The phone arrived last Tuesday and has barely been out of my hand since.

The hardware is fairly similar to the iPhone in shape, but a matt-black back casing and sort of purplish-metallic looking trim. The screen may be slightly taller than the iPhone, but only just.

Android is quite a cool OS, though I cannot tell how much is core Android and how much is “HTC Sense” which comes as part of the phone. One thing to say is that while an iPhone feels like a phone with lots of pages of buttons, the Desire is somewhat more like a computer. Technically it IS a computer – It is running a 2.6.29 Linux Kernel and you can hack a root account on it, though I have not done so (yet? Yeah, I surprised even myself here – I thought I would be hacking it and upgrading it to the latest Android straight away, but I am just enjoying all it can do right now)

I have 7 desktop screens, and swiping left or right moves between them. Each one can be filled up with application icons or shortcuts, or many applications also have “widgets” such as a clock with weather forcasting on it (clicking on the weather opens the weather app showing the weeks forecast).

Similarly I have a calendar widget showing me what is coming up from my Google calendar, and clicking on it takes me to the Google calendar application.

The touch-screen is a capacitive type and behaves wonderfully, though typing on the keyboard does take some getting used to.

The integration of the phone is quite incredible. Adding a twitter account and setting to get alerts whenever someone mentions me and now my phone beeps, vibrates and shows a twitter update in the pull-down status panel alongside text messages.

Facebook and Google integration however are far more impressive. Setting a Facebook and Google account and once it syncs I can see all the people I know in Facebook and all my Contacts in Google on my phone. Not only are they visible, but if it can it links the accounts (you can manually set links too) so that all the data shows up together. So for example, I have friends that I only had a mobile number in my phone, and email address in Google, and now that all shows up together along with their Facebook profile photo and more details from Facebook! (If only I could then force all that data back into my online Google address book)

I suspect the iPhone appstore is slightly better stocked than the Android Market, however there are still plenty of very good apps out there, and many are free (yes, there is a free lightsabre app if you really need it)

Google Maps is rather cool, and even has “Navigation”, which gives voice directions while driving (or walking) – It even pronounces the names of streets, though not particularly well.
If you are walking the route, at the touch of a button you can see the route through Google’s street-view so that you can see where the turns really are, though I suggest not trying this while driving.

As I am with 3 as my provider, I fought my way through their website to get the MSN and Skype applications, which once found were easy to install. One odd thing is that both Skype and MSN only work if you have good 3 signal AND have turned off wireless. It seems strange to me as there is no harm in letting you use wireless, but I guess they have their reasons (I believe that the Skype app actually uses a GSM phone call to do the voice to their server which should be easier on their network than VOIP, but that doesnt exaplain why wifi couldnt be used)

Google Earth is pretty cool to see running on a device in your hand, but perhaps even cooler is the Google Sky app which not only uses GPS to work out where on the Earth you are, but also uses the Compass to work out which way you are facing, and the tilt/accelerometer thingy to work out which way your phone is facing. Holding the phone in front of you, as you would taking a picture, it shows the stars, planets and constellations that are visible in that direction. As I know almost nothing about star constellations this is rather interesting to me.

Okay, so Google have influenced the apps a lot, but they did write a lot of the OS, and it is perfectly fine to use without a Google account (it does POP/IMAP and Exchange for email), but I think you get more out of it if you use Google already.

One thing I have yet to try is application development: I’ve only had it a few days – come on!
Looking at the developer docs it looks pretty straightforward – Eclipse IDE, Java classes provided, you should even be able to debug your app running on your phone via the USB cable. The only downside I have heard is that the GPS libraries require licensing, though apparently it will work in debug mode on your phone. It also appears that there is a $25 signup fee for the Android Market, but that doesn’t seem too extreme (especially when you compare it to $99 per year for the Apple app store)

One thing worth checking: I found (as did many other people if you search for it) that having the Twitter account enabled for updates (for example in Friend Stream) caused the calendar to continually poll for updates. This uses lots of battery (and probably bandwidth). It seems that calendar is the task responsible for nearly all background updates, so don’t just assume that it is your calendar using all your power or bandwidth, it is probably something asking calendar to do lots of updates

If you think something is using too much battery power, download the app “Spare Parts” from the Android market, and in it select “Battery History->Partial Wake Usage” and see what comes top. Mine used to show Calendar, but after removing the flickr account settings from the core OS “Settings->Accounts & Sync->Flickr->remove” and restarting the phone the bars are all very much smaller (and Calendar barely features on the usage)

Spare Parts looks incredibly useful, as you can also track bandwidth usage.

Posted from WordPress for Android

O2 Joggler

Anton Piatek — Wed, 19 May 2010 17:08:27 +0000

My O2 Joggler just arrived and it is quite an interesting piece of kit.

I’ve not had much time to play with it yet, but the O2 software stack seems a bit limited. Google calendar can be installed, but no mail, and I’m not sure the calendar will pop-up if something is approaching.
No web browser was a major failing in my opinion – Sure you get Sky News, but the interface for that is rather simple and I expected better (feels like WAP on a phone!)

The weather apps (for some reason there are two) are ok, but the default one seems to show some odd forecasts (Friday, Thursday, Saturday with Friday and Thursday showing night forecasts for some reason)

I have yet to try uPnP for pictures and music, but the internet radio plays BBC stations fine.

The traffic app looks a bit simple, though the google maps app is nice. The messaging could be interesting as it can send/receive texts, but as I can’t see me using it much. The O2 calendar I have yet to try.

After poking that far, I decided to boot Ubuntu, so following http://www.stephenford.org/joggler/ I downloaded the Ubuntu image that has been customised for the Joggler, copied it to my usb key and it booted fine.

Getting wireless up was ok (at least I could copy and paste the wpa2 key from a file I put on the USB key before booting it, rather than typing the rather long random string I have on the on-screen keyboard as I had to for the O2 software), but I did find that using the touch-screen is not a good alternative to a mouse (and the on-screen keyboard can be really annoying!)

At least Ubuntu gives you a web browser (Chrome and Midori are installed by default in this image), but it is still tricky to use.
I had to increase the font sizes just to get windows that I could click the menus on.

So far the only thing it is actually great for is solitaire – which is a rather expensive deck of cards!

I need to try some of the hacks at http://www.jogglerwiki.info/ like installing telnet/ssh and then see what I can hack on top of the O2 software, as it seems better built for a touchscreen and keyboard-less device, though I am not sure what I will be able to get working. It does appear to have flash running on it, and one site suggests that any flash .swf file can be launched easily

Update: Good review at http://jtlog.wordpress.com/2010/05/20/new-clock-radio/

GPS scripts

Anton Piatek — Sun, 10 Jan 2010 14:21:56 +0000

I have a simple walking GPS (Garmin Etrex H) which is great for walks, hiking etc. I wrote about using it under Ubuntu earlier.

I can input waypoints and use it to direct me where to go and it can be set to tell you where you are in BNG (British National Grid, i.e. Ordnance Survey map coordinates) so working with a map becomes almost trivial. One thing I found I needed was a way of creating a GPX file to upload to the GPS which is formed from these BNG coordinates. Some of the walking books I have give BNG waypoints but you can’t just upload that data into the GPS (unless someone knows better? I never got it to work).

So I set out writing a script to do this – BNG_to_gpx_route allows you to enter a list of BNG waypoints and it either outputs the GPX file (to file or stdout) or even writes direct to your GPS if you have gpsbabel installed!

I may well write a few more scripts to help me with my gps as I come across the need (though if you have a need maybe I will too, so let me know if you have a thought for a useful util for your gps).

Another good way to plan a route is with Marengo GPS Route Planner, which allows you to draw a path with a google-maps interface, and then simply download a GPX file which can again be uploaded to your GPS with gpsbabel

My GPS also records where you have walked which is known as a track. This can be used for finding your way back if the walk was difficult, or giving to someone else to follow your walk. One other use is for geotagging your photos, which means you run a script against your photos to add to the “meta-data” which describes details of your photos, and with the track file from your gps it adds the coordinates to the file, so when you upload them to flickr or zoomr they know where the photo was taken!

Like many others, I wondered if I would have to write this myself but it turns out there is a really good script called gpsPhoto (thanks to bluemonki for pointing it out) which already does this!

It is pretty simple, you just need to give it the path to a gps file, or directory of files, and a list of photos or a directory of photos, along with a time offset (in case your gps time and camera are different (i.e. a few minutes out, or even an hour out for daylight savings time etc)) and it will add the gps coordinates to your photos. Apparently it even works on Canon raw files, so hopefully I could just tag photos as I get them from the camera and then any time I create a new jpg from them they should automatically have the gps data in them!

Cross-platform realtime collaborative editing

Anton Piatek — Wed, 11 Nov 2009 12:04:21 +0000

I recently stumbled across Gobby:

Gobby is a free collaborative editor supporting multiple documents in one session and a multi-user chat. It runs on Microsoft Windows, Mac OS X, Linux and other Unix-like platforms.

It looks really cool, and the realtime-editing would be very well suited to trying to draw up any form of document or source code at the same time when you will have too much activity for trying to use a code repository.

It is a shame Gobby does not have hooks builtin to allow loading code from a VCS or DVCS (that would be cool), but you can launch it headless on a server with an auto-save directory and then all connect in and start loading documents. There are times when I have wanted something like this, particularly when you are starting out a new piece of code and have several people wanting to get started right away. Once the pace dies down, it probably makes a lot of sense to move the file to your source code control system, but for that initial burst this looks like a fantastic tool

powerline networking

Anton Piatek — Wed, 30 Sep 2009 12:00:47 +0000

After moving into our new house, I contemplated running a pile of ethernet cables before we got the new carpets laid, as I have always had issues with wireless. In the end I didn’t find the time to rip up floorboards and skirting boards to lay the cables I wanted, and as it turns out the solid brick walls reduce the wireless networking strength down to almost useless (it sometimes connects upstairs, and sitting at the wrong side of the dining-room table loses the signal).

I decided that powerline networking might be a better solution. I looked at linksys’ range and decided on the PLK300 kit which is a 200mbpss kit with a 1-port adapter, and a 4-port adapter. I suspect that 200mbit means 100mbit/s in real terms as powerlines have only one pair of wires, so it is simples (as opposed to ethernet’s two pair that gives full duplex).

Getting the encryption was simple enough – press the right incantation of buttons, but I actually have no way of testing the encryption works. As for real-world speeds, I only get about 4-5Mb/s (32-40mbit/s) which is not as fast as I was hoping, but the wiring in my house is probably quite old and it is going from the downstairs power ring to the upstairs ring. I think it is probably fast enough, and as wireless is slower (and less reliable) the only other alternative is carving up the floor and walls to run cable – and I am too lazy…

Of course, as the devices are just ethernet bridges, it works seamlessly with linux and my existing network, and has almost no configuration. The power rating of these devices totals about 50W, but they seem to use less than that according to my Current Cost meter.

BCC releases iplayer desktop for linux

Anton Piatek — Sat, 20 Dec 2008 19:04:00 +0000

BBC recently announced that iplayer now supports downloads on windows an linux, in the form of iplayer desktop. You can get started on the iplayer labs page.

So I decided to try it out…

iplayer security dialog - extremely bad! Why can't they get a digital signature for the download?

First I had trouble upgrading flash – Installing it was easy, but I found I still had a flash 9 install listed in my about:plugins page. Following the Flash – MozillaZine Knowledge Base page helped me solved this (it turns out I had a flash 9 file in my ~/.mozilla/plugins folder)

Then it was time to install iplayer. First it installed Adobe AIR, which was simple enough. Then the iplayer desktop app installed inside AIR – the security dialog for this was particularly unappealing as it did not have any knowledge of the publisher, let alone a secure signature or certificate to assure me it was really BCC content I was installing

After that it was plain sailing – Top Gear started downloading straight away, and was done within minutes.

It plays great, works fullscreen (though my laptop can’t manage full screen well, I probably need to look at setting up 3d acceleration which I didnt do when I installed it ~2 years ago as the drivers were rubbish), and the volume still goes to 11 like the iplayer.

Amazon UK online music store opens

Anton Piatek — Sat, 06 Dec 2008 18:04:59 +0000

Amazon UK recently launched their online music store, which seemed top open much quieter than I would have expected. It did make national radio (Radio 1) on my way home from work, however they were more interested in the fact that albums are £3 each (I think this is promotional price) than the fact it is DRM free.

My biggest problem with iTunes (apart from the fact the iTunes software doesn’t run on linux) is that the files are DRM protected. This means I cannot play them on linux, and cannot play them on any portable player other than my iPod. Amazon’s music is mp3, DRM-free and will play on nearly all devices, all operating systems and I can even burn a mp3 (or normal audio cd) of songs to play elsewhere.

I seem to remember Apple trying to go DRM-free but the music companies objected (mind you, the music companies also wanted Apple to increase prices) but that doesn’t seem to have affected Amazon.

The radio news I was listening to suggested a price war resulting from this, however I am more interested in getting music I can actually play how and where I want.

As a side story, a friend recently had to get a new computer as their old one died. They got the music they had (windows WMA files, which were DRM protected) from the old disk, but had a hard time playing it. The new computer wasn’t allowed to play it! It took a lot of effort to get it working.

This is my biggest objection to DRM – It actually make things worse for the consumer, including making it harder to play and harder to backup.

LightScribe on Debian – burn your cd/dvd labels!

Anton Piatek — Sat, 25 Oct 2008 16:26:13 +0000

I have started doing some photography for other people, so decided I should really put some effort into how I present the photos. I thought about buying an inkjet for printing labels, but they weren’t all that cheap and from my experience with inkets in the past the ink dries out and is rather expensive to replace.

I also had problems finding inkets that could print direct to cd from linux… Then BlueMonki suggested a LightScribe drive. LightScribe is a technology where you put the disk in the burner upside down and it etches a label onto it. Of course you need a new drive and specific media, but the drives are available for £20 and media is less than 30p each, which is more expensive than a normal dvd+r but not a problem for occasional use.

I picked up a Samsung drive because it was cheap, and came with 3 faceplates, so I could match my silver pc case. I was a little worried that I would have a hard time making the software work, but it was really easy.

Install the LightScribe system software, available in 32bit .debs, and install it with sudo dpkg -i
Then install the LaCie LightScribe labeller software which you will have to convert with alien –scripts before you can install it (you might need to install alien from apt/synaptic first), then install it with dpkg as well

You can also use the LightScribe simple labeller if you just want text, but its a little boring to do that. If you do use it, after aliening the rpm and installing it you might need to change the group of /opt/lightscribeApplications as Debian doesnt have a wheel group. I used “sudo chgrp cdrom -R /opt/lightscribeApplications” as I am in the cdrom group and that sounded the most sensible group name.

You will probably want to work on your images with Gimp, or your favourite image tool, to add text to your cd label, though you could just use an image without text.

I found a cd template file here, which I modified to make square and make the middle transparent so I could add a layer in gimp and add stuff in the right places, then turn off the layer to save the image for burning. My version is here, consider it in the public domain.

Once you have your cool cd label image created, you want to burn it. Simple run “4L-gui” (I couldnt find an icon for this, so you might need to run it from the run dialog or a console window), select your image, move it and scale it as needed then hit the burn button in the top right.

It all worked straightforward, which was surprising. Best of all it seems that the LaCie software will work on any LightScribe drive so buy whichever one you fancy.

There is a lot more software out there for windows, but you will probably want to do more than they let you, and then you simple need Gimp and something to burn an image.

It is worth pointing out that burning the label takes ~15 minutes, but I didn’t mind. I do have to look out for what colour media you can buy as I think that could make quite a difference to how the final result looks.

EA Hit with Class Action Lawsuit over Spore DRM

Anton Piatek — Thu, 25 Sep 2008 12:22:43 +0000

EA Hit with Class Action Lawsuit over Spore DRM

…a class action lawsuit has been filed against Electronic Arts in federal court, which alleges the company defrauds its customers by not disclosing the installation of SecuROM copy protection as part of Spore’s installation.

…

“Consumers are given no control, rights or options over SecuROM,” the complaint continues. “The program is uninstallable. Once installed, it becomes a permanent part of the consumer’s software portfolio. Even if the consumer uninstalls Spore and entirely deletes it from their computer, SecuROM remains a fixture in their computer unless and until the consumer completely wipes their hard drive through reformatting or replacement of the drive.”

I wonder if I can join the lawsuit? I only use my windows image for playing spore, so probably don’t care that the copy protection software is not removable. I am more bothered that I can only install Spore 3 times (ever), as I will likely delete windows (hard disk failure?) and then later decide I want to play spore again (at least I have with all other good games – Quake II, StarCraft, Diabo II, etc)

Isn’t SecuROM the same software that Sony had problems with? Or am I getting confused. Sony lost their lawsuit (though it was DRM on a music CD), so I wonder how much chance EA has…