AWS on iMil.net

Score!

Sun, 11 Jun 2017 11:42:00 +0000

This happened:

Launch the AWS Console from the CLI or a mobile phone

Sat, 20 May 2017 15:48:47 +0000

At ${DAYJOB} I happen to manipulate quite a few AWS accounts for different customers, and I find it really annoying to log out from one web console, to log into a new one, with the right credentials, account ids and MFA.

Here you can read a good blog post on how to enable cross account access for third parties and use a basic script to open a web browser to switch from one account to the other.
I liked this idea so I pushed it a bit further and wrote this small piece of code which allows you not only to switch accounts, but also to simply open any AWS account from the command line.

Ansible and AWS ASG, a (really) dynamic inventory

Fri, 05 Aug 2016 14:07:00 +0000

I found myself searching ridiculously too long to achieve what I believed was a simple task: to apply an Ansible role to newly created instances… started by an Auto Scaling Group. If you’re used to Ansible you know that it relies on an inventory to apply a playbook, but obviously, when you’re firing up EC2 instances with the same playbook, you are not able to know what will be your virtual machines IP addresses, nor can ec2.py, the recommended method to deal with dynamic inventories.

EC2 VPN connection informations (updated)

Sat, 06 Jun 2015 11:19:42 +0000

For a mysterious reason, EC2 VPN connection informations are stored in XML within the JSON data retrieved by either boto or the awscli command line tool.

Here’s a quick python snippet to convert those datas in a convenient, easily parsable dict:

Combining this piece of code with jinja2 could help you generate racoon (or whatever IPSec software you use) on the fly.

Update

here’s a complete example of an automatic generation for racoon / ipsec configuration files using the previous snippet, along with jinja2.

Latency based Alias DNS record in Route53

Thu, 04 Jun 2015 23:05:56 +0000

Yes, I know I write a lot about AWS these days, but you know, obsession is my thing.

So as I wrote earlier, I generate my CloudFormation templates using troposphere, and the one thing I had to finish today was to register a latency based Alias record on Route53 for an ELB. While Route53 GUI is fairly easy to use, I’ve been stuck on its programmatic emanation for quite a while, so here’s a troposphere definition of such a CloudFormation object:

Rock your CloudFormation with troposphere and boto

Thu, 04 Jun 2015 10:55:48 +0000

So you’re using AWS CloudFormation in order to bring up complex infrastructures; haven’t you already told yourself that instead of writing down all those JSON lines by hand, you could bring more fun to your architect life? I did, and I found a way to programmatically design a whole architecture using troposphere and boto3. Simply put, troposphere gives you bindings in order to generate CloudFormation’s JSON template, but hey, it’s python, meaning that you can create loops, use conditions and even dynamically build objects.

Reserved Instances mystery solved

Thu, 28 May 2015 11:40:56 +0000

AWS is an amazing piece of cloud, but the documentation is not always clear. I’ve been scratching my head trying to understand how Reserved Instances pricing was applied to actual instances. First I was searching for a “Launch a Reserved Instance” button, or even “Associate this Reserved Instance”, but no, nothing. I found the official documentation to be quite evasive so I took my chance on the ##aws IRC channel on irc.freenode.net; there I found a very friendly community that explained me (and many more after me) the simple truth: It’s all automagic!

aws cli and jq filtering

Wed, 20 May 2015 23:07:16 +0000

Long time no see huh? ;)

I’m diving into Amazon Web Services for some months now, and I must say I’m pretty impressed by the overall quality. Compared to the other “clouds” I’ve played with, it’s the most mature and comprehensive by far.

While writing a couple of tools to make my life easier, there’s one piece that took me longer: filtering the output of the aws ec2 describe-instances command. The output is in JSON, which is quite nice you might say, and it is, but when it comes to interact with JSON in the command line, things can get a little messy.