[chef] Re: Re: Re: Automatically starting a new EC2 instance with Chef

["Jeffrey E. Sussna" < >]

Very nice. I presume that putting everything in the user data script is what 
makes ELB wait for the chef run to finish before it considers the instance in 
service?

I think your post may also answer a question I was about to pose to the 
group. I want to use chef/EC2 to build an on-demand regression test 
environment. When an instance gets tipped up, it doesn't know what regression 
suite it will run, so it doesn't know what software needs to be installed 
(the suite itself, plus needed libs and exes). The question is how to 
dynamically assign roles to nodes. If I understand your solution (and chef) 
correctly, whatever creates the user data script could dynamically set the 
value of role[] in the runlist. Then, when chef-client registers the instance 
with chef-server, it would say "hi, my name is regression-box-42, and my role 
is regression-suite-23", which would cause chef to configure it with the 
appropriate software for "regression-suite-23". Am I right?

On May 28, 2011, at 12:30 AM, Edward Sargisson wrote:

> Hi all,
> I followed the advice (and made great use of Avishai's user data
> script) and now have my site running so that AWS Elastic Load
> Balancing will automatically detect an instance going down and bring
> another back up - configured from the standard OS image using Chef.
> 
> I hope I don't breach the standards of this list by including a link
> to the blog post I've written which details all the steps.
> http://www.trailhunger.com/blog/technical/2011/05/28/keeping-an-amazon-elastic-compute-cloud-ec2-instance-up-with-chef-and-auto-scaling/
> 
> Many thanks,
> Edward
> 
> On Sat, May 14, 2011 at 12:36 PM, Avishai Ish-Shalom
> <
 >
>  wrote:
>> If you want to achieve this goal with the minimum amount of work, create
>> a launch configuration with a user data script that installs ruby,
>> installs chef, write the validation certificate, chef config and
>> bootstrap json then launch chef. Ubuntu images are bundle with
>> cloud-init which is able to read shell scripts from user data. In other
>> words, edit the attached script and use that as the user data for new
>> instances or autoscaling groups.
>> 
>> BTW, a native chef plugin for cloud-init is waiting to be merged. If and
>> when it's included, launching ubuntu images with chef will become
>> ridiculously easy.
>> 
>> Regards,
>> Avishai
>> 
>> 
>> On 14/05/11 16:55, Edward Sargisson wrote:
>> 
>>> Hi all,
>>> What tools and services are available to automatically start a new EC2
>>> instance with Chef?
>>> 
>>> My site has just one server and yesterday it failed. Unfortunately, I
>>> was at my day job and couldn't do anything about it. It's configured
>>> with Chef so starting up a new server with knife then using Opscode
>>> Platform to put the roles on was reasonably easy (it could be easier
>>> but I have some issues to fix).
>>> 
>>> What I would like is for some service to realise that my server is
>>> down and then call Chef to setup a new one. Amazon Auto Scaling almost
>>> does this - the issue is that it merely starts an AMI and doesn't do
>>> anything cleverer than that. My Chef setup assumes a brand new Ubuntu
>>> image and goes from there. I suppose that, for future use, whatever
>>> solution I use needs to also listen to the CloudWatch metrics to scale
>>> up and down when required.
>>> 
>>> So:
>>> Do I write an image which bootstraps chef automatically?
>>> Or is there some other way to solve this problem?
>>> 
>>> Thanks,
>>> Edward
>>