I know its so tempting to reach for the “turn off SELinux” switch but wait, its actually very simple to make SELinux allow Dropbox to work.

It turns out that Dropbox tries to do some naughty stuff that SELinux is there to protect us from – namely executing out of the memory buffer. This type of thing is usually done by programs trying to do malicious things on the system and happily SELinux protects us from this – but that prevents Drop from running.

How to Fix It

There is a nice and simple way to fix this and no I dont mean disable SELinux

There is a boolean that you could flip that turns off this protection – namely allow_execstack

sudo setsebool allow_execstack 1

However this is going way to far as you all now allowing any process to execute from stack, which isnt a good idea.

The best way is to tell SELinux that you just want Dropbox to be able to do this and nothing else. The way that you do this is you label the executable file, in this case /usr/bin/dropbox, as type execmem_exec_t

You can do this with a quick chcon, but thats not the best way to do it, the following two lines will fix Dropbox to work with SELinux

sudo semanage fcontext -a -t unconfined_execmem_exec_t /usr/bin/dropbox
sudo restorecon -v /usr/bin/dropbox

Now if you take a look at the SELinux contetxt of the file, you can see its got the right label

ls -lZ /usr/bin/dropbox
-rwxr-xr-x. root root system_u:object_r:execmem_exec_t:s0 /usr/bin/dropbox

If you spend a little time to understand the basics of SELinux (file contexts and booleans) you will find it is quite straight forward to work on a system with SELinux turned on

If you are interested in learning more about this stuff, check out the Dan Walsh blog

OSG

Like all good conferences you are inevitably faced with with the problem that there are multiple talks that you would like to see but the are being held at the same time. Some of the talks inevitably make it online and this years is now exception. They are available here

Of course, like most conferences, its not all about the tech. FOSDEM is the conference where I see the most socialising. I guess the fact the Belgium has some of the finest beers in the world helps this no end

Each year I come away from FOSDEM itching to get my hands on some of technologies that I have heard about, and this year is no differnt. Spacewalk is a project Ive been interested in for about 6 months now and it seems to have had some really nice features added soon. Im just waiting for them to break the need to use Oracle before I really dive back into it. PostgreSQL is on the roadmap and should be here soon.

There was an interesting talk by Linsay Holmwood about Flapjack, Cucumber Nagios & Visage, both of which Id like to have a play with. Another very interesting talk was give by a couple of Guys from Facebook. They were talking about how they have scaled Facebook with Open Source tools and the additional tools that Facebook have created and Open Sourced. Full marks have to go to Facebook for this, nice to see a company contributing back to Open Source so much. You can go to facebook.com/opensource to find out about this.

I have also come away from FOSDEM ready to give OpsView another try, @dotwaffle extoled its virtues, so I certainly need to take a look at that. I have to say it was a real priviledge to listen to Andrew Tanembaum talk about Minix as well, I had no idea about some of the cool technologies included in it such as the reincarnation service. He was an entertaining speaker also which always helps.

I mentioned that FOSDEM seems to grow each year and take on more and more talks, inevitably this leads to some talks being put in rooms that are too small for the level of interest. I really wanted to take a look at some of the Coreboot talks but the room seemed to be at capacity right from the start. I guess I need to use those online videos I mentioned above.

Each year there also the usual swag available and this year was no different. I came away with a new TShirt and Max Spevak (Fedora Community guy) had brought over some excellent “powered by Fedora” case stickers. Spreaking of which, Max had also organised a Fedora Activity Day on the Friday afternoon, which was a nice way of starting off the weekend, a kind of pre-con. It was great to see so many Fedora Ambassadors at FOSDEM again this year.

All in all I had a great time there, a time that always seems to be over too quickly. It would be great to seem then extend the conference by a day or two. There were over 200 lectures given over the space of two short days, so Im sure there is enough content. I guess it depends if they could secure use of the University on weekdays that may be the limiting factor.

Anyway, a *very* big thanks to the organisers, the sponsors and the people who volunteer their time to make sure that the conference runs so smoothly. If you have never been to a FOSDEM, please make sure to see if you can go next February – watch the site for the exact date.

Other Conferences
While Im talking about conferences, please be sure to check out
LOAD www.loadays.org April, Antwerp BE
OGGCamp oggcamp.org March, Liverpool UK

Well now, if you have a WordPress blog and an Android phone you too can have this functionality. WordPress is now in the Android app store, and what’s more its totally free.

Thanks to readwriteweb for the headsup.

Note: This post was done from my phone, alhtough the above link was impossible to do and categories also seem to be broken at the moment but this is a 1.0.0 version.

Im a very happy geek now!

Once logged in you will only have access to a web browser – the browser will be Googles Chrome Browser, as you may expect. There will be no desktop or other apps, everything will be done from the browser. They are going to build in functionality for  working offline, for when you are not connected to the net.

Many people, even in the Linux world, seemed to be opposed to this but I can only see it as a good thing. Under the hood its based on Linux, Google have said they have been working with Ubuntu in this respect. Google have stated that Chrome OS will be Open Source and released the current dev version on Chromium.org. From my point of view I think its going to be good for the Linux platform. The improvement in boot speed and hardware drivers alone can only be good.

I really dont know why Google seem to have so much opposition. I understand peoples concerns about a company that knows so much about its users but they are the only company to have a “do no evil” moto. Whats more Google are also a very transparent company, the information that they have on you can easily be found and deleted if you so wish. For example, if you want to view or delete your web history, just go here and do so.

I do wonder how many people know about the Data Liberation Front, a team of Google engineers who work solely on making sure that you can easily get your data in or out of as many Google products as possible, as simply as possible.

I really do feel that Google are a friend of open source. Their Android phone OS is Open Source and while I know there was some concern over their reation to the Cyanogen mod, when you read into it, you can understand their point of view – plus they worked with the Cyanogen guy to come up with a work arround.

Also, lets not forget the Google Summer of Code. Each year they make this great contribution to Open Source. Im sure its not entirely altruistic but never the less it is a very valuable contribution.

Recenlty Google seemed to cause some more negative ripples with their aquistion of the Etherpad Project. I think anyone who has tried both Wave and EtherPad will understand why Google wanted Etherpad. Etherpads real time document editing is much better than the current Google Wave client. So the Etherpad team have been pulled off Etherpad and put to work on Wave. The controvesy was not so much about this but that the fact they closed Etherpad, a product that many people use and find invaluable. They gave people about a months notice to trasition away from it. The thing I will say about this is that as soon as they became aware of the communities concern, they re-examined the decision and have re-opened EtherPad – in a matter of days. They then said, in a very open way “what were we thinking”.

UPDATE: They have also released the sourcecode for Etherpad under the Apache Licence

This brings me on to Google Wave.I know that people who have been able to try this out are not that overwhelmed with it. What I will say is that its very early days in this products development. I would also so that Wave is all about the protocol underneath that lets you collaborate on document editing and the current Wave client is just the first implementation of a client – there will be other clients. In other words, think of Wave as SMTP and the current client as Outlook Express. There will be better clients

My main point about Wave though is how Google have gone about this. They said, from the outset, that they wanted to create an open protocol, just like SMTP. They also built federation in and they have also desinged it to be extensible, so that people can develope their own plugins. This shows that they are a company that just seem to get it. The understand why Openess is important.

So whats the point of this article, well what Im really saying is give Google a break. Yes they have a lot of information about us and its right to be concerned but their every action to date seems to have been honorable. Lets save the paranoia for companies that treat us and our data appallingly on a daily basis

I’d love to hear your opinion of this subject, please leave a comment or use the contact form

OSG

On a web server, the service runs under an account context – in my case the account is apache. Now all the files in the root of my WordPress folder are owned by root, and only root can write to them. So this is why auto-upgrade doesnt work. Changing the ownership of these files to be Apache would fix it. However, this means that if ever Apache is attacked and breaks giving the user access as the apache user, he would have read-right access. Its a pretty unlikely scenario I know but hey, call me paranoid

If you want your WordPress to be autoupgradable, you simple need to change the ownership of the wordpress files to apache so that the webserver has read/write access.

Ive decided to come up with two scripts, one that is run before the upgrade, that changes the ownership to apache and one that runs after the upgrade to change the ownership back. Its really very simple, so here they are

Before upgrade

chown apache:apache /var/www/html
chown apache:apache /var/www/html/readme.html
chown apache:apache /var/www/html/index.php
chown apache:apache /var/www/html/license.txt
chown apache:apache /var/www/html/xmlrpc.php
chown -R  apache:apache /var/www/html/wp-content/
chown -R  apache:apache /var/www/html/wp-includes/
chown -R  apache:apache /var/www/html/wp-admin/
chown apache:apache /var/www/html/wp-*

chown root:root /var/www/html

chown root:root /var/www/html/readme.html

chown root:root /var/www/html/index.php

chown root:root /var/www/html/license.txt

chown root:root /var/www/html/xmlrpc.php

chown -R  root:root /var/www/html/wp-content/

chown -R  root:root /var/www/html/wp-includes/

chown -R  root:root /var/www/html/wp-admin/

chown root:root /var/www/html/wp-*

chown root:root /var/www/html
chown root:root /var/www/html/readme.html
chown root:root /var/www/html/index.php
chown root:root /var/www/html/license.txt
chown root:root /var/www/html/xmlrpc.php
chown -R  root:root /var/www/html/wp-content/
chown -R  root:root /var/www/html/wp-includes/
chown -R  root:root /var/www/html/wp-admin/
chown root:root /var/www/html/wp-*

Its probably not really necessary but it feels better this way

Please note, my WordPress files are in the root folder, not in “wordpress” or “blog”, so you will need to adapt the above for your own case

OSG

Long Time Fan
Ive been a long time (read 2000/2001) fan of VMware – they were the first and, you could argue, still are the best in their space. Im a Linux fan, have been for a while and one of the reasons that I liked VMware was because the software I bought from them (yes I paid for Workstation and upgrades) was available for my OS of choice. Whats more they took the time to make sure that the windows worked with GTK2 looks. This to me meant that they liked their Linux users, they gave a crap about us.

I was so disappointed when I moved my home server from VMware Server 1 to VMware server 2 as the Linux client had gone. At least its been replaced with a web interface, that seems like a good idea – then all operating systems can manage the server. The interface came in for some criticism but it did everything I needed it to for the most part and I could manage my home VM server while out and about.

Times change and VMWare came out with their free version of ESX – namely ESXi. Now while ESX also had a decent web interface, ESXi did not. Your only choice of a graphical interface now meant you had to run Windows. So I stayed with Server 2.0

Recently I became aware of “VMWare Go” which was a “new web interface of ESXi users”. Yay I thought, good times! Alas no, when I went to log in I was prompted with a message that said “Your broswer must be at least Firefox 3 or higher, or IE v7 or v8 to use this site”. Thats odd I thought as I am running 3.5.5. What I very quickly realised is that this wasn’t to do with browser, it was to do with OS. I tried the site from my dual boot laptop (the only place I have Windows left these days) and I was able to get in with Firefox 3.5.5 on Windows but running the wizard prompts you to download components like the .net framework and other such single platform technology. How utterly disappointing

End of the Road
What did we do VMware? Why did you abandon us? Well anyway, I guess its the end of the road then old friend. Be happy.

Im off to migrate my stuff to Xen or KVM. Im not sure which yet, Xen has Amazon using it and Citrix seem committed to open source. In fact Ian Pratt was on FLOSS Weekly earlier in the year, so they seem to have the right mindset. On the other hand the Redhat road map points to KVM.

Anyway, watch this space. Im going to take my time to decide which to chose – i am on the rebound after all

OSG

Faulty by Design
The Rocom devices seem to last about 12-18 months before going faulty. I suspect that its the flash cartridge but being a proprietary design means its not easily replaceable.

Requirements
Ideally the device will have no moving parts; we did away with the original devices (which were literally CD players) because they were unreliable and not remotley manageable.

All we really need it to do is

• play music on a loop
• automatically start after power interuption
• be remotely managable

Open source
The continued failure of device after device (we have about 70 of them accross EMEA) got me thinking, there must be a better way. I looked at Shuttle PCs but they failed the moving parts criteria (well there are ways but it didnt seem a good fit). Then my mind we to a very small fanless PC that i bought a couple of years back from Aleutia. So I took a look at the website to see if it was viable. The original device has now become the Aleutia T1

While the original device ran Puppy Linux but all the current ones run Ubuntu. Great, so the device is small, fanless and runs a very good, open source, operating system, and has a network port. So far so good.

Next I needed to work out if it would automatically start after a power outage. I dropped a quick email to the guys at Aleutia to see if this was possible and they very quickly responded to confirm that there was a BIOS setting for exactly this requirement. The final part was playing music on a loop. I was expecting it to be quite easy to acheive and I wasnt wrong.

The method of music playback I have gone for is called MPD (Music Playback Daemon), which is easily installable (its in the Ubuntu repos). I quickly installed MPD an uploaded an MP3 to the folder. Finally I added the MP3 to the playlist and set it to repeat and I was in business. Within 30 mins of unpacking the T1 I had it playing back music.

I shutdown the T1 and removed the power adaptor to test its ability to power on automatically. No sooner than I applied the power the device booted up, once the device had booted, MPD started playing the music – WIN

Final Steps
Now that I had a working device up and running, I need to think about how its supported within our company. I guess other people wouldnt be happy with SSHing into it to control it (which is really very simple actually). What I needed was a front end. Needless to say there are many front ends written for MPD. I went with a very simple web front end called MPDPlayer – its one of the many open source front ends listed on the wiki.

Ive done a little customisation of this and added a file upload button so that the whole process can be managed from the web interface.

Test Test Test
Im now in the process of testing and I do seem to have come accross a bug where playback stops after a number of days. I could just schedule a reboot of the device every night but I would prefer this to be a last resort. The MPD forums have given me some into on how to debug MPD, so I shall persue that.

Conclusion
So whats the catch? Well there doesnt seem to be one, plus this solution comes in nearly £100 cheaper than a Rocom and comes with a three year warranty rather than Rocoms 12 month one. Finally, as it uses a standard compact flash card, if it does go faulty, we can very easily replace it.

Overall Im really pleased with how easy its has been to “scracth my own itch” using existing open source projects. I intend to contribute my file upload button back to the MPDPlayer guys in the true Open Source fashion. Im also hoping that this experience will open my companies mind to using more open source solutions in future.

As ever I welcome your comments

OSG

The process was quite straight forwardand their clear pricing meant that I could be sure roughly how much it would cost. The only part I couldnt work out is the bandwith costs. Anyway I decided to leave OSG with Amazon for one month so that I could get an idea of the total cost of hosting a server instance with them.

Its been about a month now and the costs are in. The bandwith costs were tiny (probably due to the very small ammount of traffic that my site gets) and so my calcualtions were spot on.

Does it compare?

How does it compare ? Well thats not a straight forward comparison as my old server had 512megs of Ram and the smallest Amazon instance is 1.7gigs. So while the Amazon instance is more expensive, when you compare it to a server with the same amount of RAM its actually a very good price.

That said, I dont need all that extra RAM, so I have elected to move OSG back out of the Amazon cloud and back to a hosting provider.

Where did I go?

I have moved over to Linode – these guys seem to have good feedback on http://www.webhostingtalk.com/ and my experience with them has certainly been very good so far compared to my previous hosting provider.

I will no doubt do a mini write up on that in a week or two but please let me know if anything isnt working

OSG

Google Wave

Ive just watch the 80minute talk about Googles Wave and I think they really could be onto something. It combines rich interaction with very social features and its kind of an opt in model, like Facebook or Twitter, where you have to add people to your system. This means no unsolicited waves.

They have been working on this for two years and it looks really good. Dont take my word for it, go and check out the video here

Finally, and I have saved the best until last, they will be releasing it under open source so that you can set up your own Wave platform and it has federation built right in so that it will interoperate with other Wave platforms brilliantly

Lets hope this finally kills off email – it had a good innings but its time for it to go now

OSG

EC2 offers you the ability to “stand up” multiple servers almost instantly, configure and run them and only ever pay for the number of hours they are up. A server instance starts at $0.10 an hour – this is for their “small Linux instance”, which is 1.7gb ram and 350gb disk space. They also offer Windows instances which are slightly more, but still amazingly low priced. This makes it extremely cost effective to use for large proof of concept work or for full time production. Anyway, let me walk you through my first steps in/on Amazons cloud.

First of all you have to have an Amazon account, as I already had one all I needed to do was to “sign up” for the EC2 service (remember you pay for what you use in server/hours). Two clicks later and Im ready to go.

In my eagerness to get started I overlooked the “Getting Started” video on the front page and decided to see how for I could get without reading the documentation. If you want the short answer – I had my first box up and running in less than 5 minutes. For the more detailed version read on,

There are a couple of steps to complete before you get you box up and running and the interface holds your hand nicely through these. Im impressed with the level of security that is setup right out of the box. The two steps you need to do (apart from choosing your instance) are both security related. Firstly you need to select or create the security group – in other words the firewall settings. There are suggested entries there already and customising it is very simple.

Secondly you will need to generate a keypair that you will need to administer the boxes. Again the wizard walks you through this step also, Once those two steps are done and you have chosen your instance type, you click on create and after a minute or so you can see your first instance change its status to starting.

Cool, lets see the console then.

The first instance I chose to create was a Fedora box, so when I hit the “Console” button I was provided with details on how to connect to the instance. For now, you connect to the DNS name that Amazon give you, which maps to a local IP address within Amazons cloud. You can also rent “Elastic IP” addresses for $0.01 per hour, I decided the funky DNS name and private IP was fine for my testing. So I SSH to the DNS name, referencing the file that contains your keypair. The provide the exact syntax that you need to use but its pretty straightforward. You are not prompted for a password as you are using, the more secure, keypairs. And thats it – you have a bash console your box.

I yum installed an Apache server and hit the page in my browser and there was the default webpage. I then went on to setup a WordPress install jas i would on a hosted server. Everything went to plan

As my first hour approached its end I shut down the instance and went out. Upon my return I wanted to try a Windows host. Interestingly the previous instance had disappeared. It seems that if you shutdown an instance, for a certain period of time, the diskspace is reclaimed. If you want to keep instances around when they are shutdown you can do this by using Amazons EBS (Elastic Block Store) which is $0.10 per gb per month.

Anyway, as I mentioned above, I decided to try a Windows box next. I selected the Server 2003 and SQL Server 2005 instance. This time the firewall settings suggested were as follows

• Remote Desktop (3389)
• HTTP (80)
• SQL Monitor (1434)

I accepted the defaults but if I was going to use it “in production” I would close the SQL port. I clicked the button to fire up the instance and a minute or two later it changed its status to “running”. Hitting the console button this time brings up a box explaining how to connect to the server, namely via RDP. Again security is there right out of the box because the local Administrator password is randomly set and then encrypted in the instances log file. To get to this password you have to right click on the instance in Amazons control panel and select decrypt password. You are prompted to paste in your key to a dialog box and a few seconds later your password is displayed.

Pointing your RDP client to the DNS name of the instance and using these credentials gets you logged onto your server – its as easy as that. This would make testing things like large scale Exchange setups, that involve many servers talking to each other, really easy and you wouldn’t have to stump up for the hardware required to do this in your own lab.

This (EC2) is just one of the services that Amazon offer. I’ve been very impressed with my first steps in the cloud, things couldn’t have been any easier to get up and running and I’m pleased to see that security has been part of the core design. When you consider that the underlying technology is Open source then I think its something we (the Open Source community) can be proud of.

OSG

Update:
There is talk on the net about Amazon open sourcing its cloud tools – this would great news and very beneficial for The Cloud as a whole. So nice to see people aren’t trying to lock down or lock you into their offerings – lets hope it turns out to be true

More Screenies

Edit:
Sorry about the lost screenshots, this was due to a major incident at my previous hosting provider. At least I had the databases backed up :-/