AWS et al have released a new version of their command line tools, most appropriately called awscli. It’s built on python boto and for example can be used as such:
aws ec2 describe-instances
I don’t want to rewrite how you set it up, the best place to start is at the GitHub page: https://github.com/aws/aws-cli. You’ll need your AWS access and secret keys, to setup some environment (I run on os x) and obviously use python and associated required packages. I like to work with virtualenv and virtualenvwrapper and here’s a good post on those tools.
What’s interesting about this tool is firstly it’s built on boto, and this is good for the boto community and python programmers like me. Actually it’s using the boto-core project which is a new version of the lower level boto functionality. For my interest, what’s interesting is that boto-core is using the requests package from Kenneth Reitz which I believe I suggested to Mitch Garnatt a while back (it’s a big *if* if I was the cause but I like to think so 
.
What’s interesting for this post is that it outputs the results in json. This brings me to my next interesting tool, jq. The idea of jq is that it’s like writing SQL for json. JQ is a standalone tool, if you use virtualenv and virtualenvwrapper you can just put your jq tool in $VIRTUAL_ENV_HOME/my_new_virtual_env/bin.
Here you can do some pretty cool stuff which allows you to summarise your EC2 (and other aws) infrastructure. For example, now I can use awscli to do things like:
aws ec2 describe-instances | jq '.reservationSet[].instancesSet[].keyName' "mykey1" "mykey2" "etc"
Above I’m asking for the keys associated with my entire list of instances. With this command below I can just grab the instance ids with their public dns values.
aws ec2 describe-instances | jq '.reservationSet[].instancesSet[] | {dnsName, instanceId}'
{
"instanceId": "i-98e793e6",
"dnsName": "ec2-23-23-57-193.compute-1.amazonaws.com"
}
{
"instanceId": "i-97ed79e6",
"dnsName": "ec2-23-21-75-169.compute-1.amazonaws.com"
}
You can see that using this approach becomes fairly powerful and the more one gets used to jq and aws commands, the more powerful it becomes. It’d be interesting to see some more examples of how this can work.
