I’m busy wiring together a new server configuration environment using Windows Deployment Services (don’t ask), Cobbler and Chef. So far things seem to be going quite well, until I bumped in to the following error trying to get a new client to register with the Chef server:
HTTP Request Returned 401 Unauthorized: Failed to authenticate!
A quick sift through Google results didn’t get anything usable. A quick sniff of the packets going over the wire though showed that it was authenticating using a signed certificate. Normally when you sign HTTP requests like that you add some kind of timed expiry. Could the problem be clock related?
Sure enough, a quick check on the new client and the server showed that there was just over an hour time difference. Getting the time on the client and the server in sync got the client registered!
After more than 5 years at ThoughtWorks I’ve decided that it’s time for a change of scenery. As much as I enjoyed the challenge of consulting, meeting new people and seeing new places – I prefer spending time with my family more. It was a tough decision to make, but I think it’s the right one for me now. I will miss many people at TW, but on the plus side I’m again working with some great people who I missed when they left TW…
As I’m going to be doing DevOps type stuff all day every day at DRW now, I’m hoping I’ll have more time to document and share the things I discover.
I’ve been putting off this post for a few months now, but I think the time has finally come to admit what I’m sure people who care have guessed for a while – active development on Buildix has stopped, and will probably not resume. The site will stay up for the foreseeable future, nothing will vanish, but nothing new will be added either.
We started the project because at the time, setting up a new Continuous Integration server was quite an arduous task. The only real option out there for a Java project was CruiseControl, and it could take a new developer days to get their first build through the system. Thankfully though this is no longer the case.
Since then the whole CI landscape has changed. Just having a single “build server” is now more the exception than the rule. It’s all about build farms these days using tools like Cruise, Hudson and TeamCity. They integrate nicely with a variety of SCM’s and story tracking tools. Setting up a build environment with these tools is really easy now. I’d like to think that Buildix at least had something to do with helping people to see how easy it could be to get a CI environment up and running, and I know that at least in the case of Cruise this is true because I’ve been part of that team.
So – thank you to all of you who used Buildix and liked it and provided feedback. Thank you also to the current big players in the CI field who put effort into making sure that looking after your CI environment no longer needs to be a full time job for someone.
A few months ago I got an email from Patrick Debois who I’d met at CITCON Europe asking if I’d be interested in speaking at the first conference aimed at System Administrators practising/interested in/sceptical about Agile. One of the key beliefs of those of us doing this already is that Agile practices are generally too narrowly focussed in their implementation. At the moment it’s primarily the Development organization who drive its adoption, but to get the most benefit Development and Operations groups within an organization need to work together.
With this in mind it was decided to call the conference DevOpsDays. Videos of the talks will be online in the archives section soon, so I’ve decided to write down my thoughts about what went well and not so well – I am a fan of retrospectives.
How often has someone come up to you and asked you what build of your software is currently deployed in a specific environment?
How many times have you come across a .jar or .dll file and wondered what version it is? Especially when using Open Source Software?
The most frightening one for me is when I’ve looked at a cluster of production servers and noticed that the .war file for the application deployed on it is a different size on one of the nodes. Which one was the correct one to deploy? Luckily this happened to me a long time ago, but I know that people out there are still having this problem today.
The solution is what I call “Self Identifying Software”. Every build of your software needs to have something that tells you what version it is and how to get back to the source code that created it. Having a build label or release number visible in your application is a good start, but it does not make your software Self Identifying. Product companies have been doing this for ever. The problem is that for that number to be useful (particularly when you’re trying to access the source code to reproduce and fix a bug) you then need to refer to a build system or release notes to find out where the source code came from (if you’re lucky). It often also does not apply to development builds. To be truly Self Identifying you need to make sure that every build (including builds developers create on their workstations) also includes enough information from the SCM system so that anyone who has access to the source code can go right back to the exact source code that produced that binary. For example, if you use Subversion as your SCM then this will be a URL and a revision number.
This is not exactly a new concept, it’s something I (and others) have been doing for a number of years now. The reason I’ve decided to write about it now though is that recently I was showing a new guy around one of the projects I’m working on at the moment, and when I showed him how to determine which version of the app was deployed he was delighted.
I’ve been doing even more reading than normal lately on the subject of Clouds lately as quite a few of us within ThoughtWorks who are going to be speaking on the subject next month are comparing notes. It follows that when I clicked the link for “The Wrong Cloud” I was not actually prepared for a delightfully entertaining paper that would contain my quote of the day:
“Today’s so-called cloud isn’t really a cloud at all. It’s a bunch of corporate dirigibles painted to look like clouds. You can tell they’re fake because they all have logos on them. Real clouds don’t have logos.”
As much as I enjoyed reading their paper, I must say that I disagree with a lot of what the guys at Maya are saying. Yes, there is a large dose of spin and hand wavey magic going on with the current leading fashion trend (that bit is totally true). Yes, it is very easy to tightly couple your application to a cloud vendor. The thing is though that it’s not that different from the tie in you get when selecting what language you use to develop your application in, which third party libraries you use or even what operating system(s) to target. The only real difference I can think of is that if for some reason the cloud vendor you’re backing stops running your app goes down, unlike all those mission critical OS/2 applications that are still running out there…
I’m pretty sure that you’d have fair warning before the plug was pulled though, especially if you’re still paying them money every month for their services.
The real questions you need to ask before doing anything on any cloud service are:
- What is the problem I’m trying to solve?
- Do any of the cloudy offerings actually help me solve that problem?
- What is the cost difference between deploying this app in the cloud vs our own infrastructure (assuming you have any of your own)?
- What is the point at which that will change? Is there a usage point where it would be cheaper for me to move off the cloud?
- If I chose platform X, how hard will it be to move to platform Y?
Cloud is not a magic silver bullet – such things don’t exist. As with any technology choice you make, you need to select the most cost effective one for the problem you have, and try your hardest to ignore the FUD.
Last year at JAOO I had the chance to speak to Markus from Software Engineering Radio about the talk I gave there on Continuous Integration. It’s finally available now over here. The slides that go along with the talk are available from the JAOO site.