Playing with Amazon Meta Data

The good thing with cloud computing is that your resource can be allocated anywhere on Earth (at least for now!) and you don"t have to care about it. It will just “work”.

But what if you need to know more? Sure some tools offer you options at creation time to control the provisioning process but what if you need to afterwards?

Information will be added to this page as I experiment the service so please make sure you come visit often!

EC2 hosts

EC2 Metadata tool

From http://aws.amazon.com/code/1825

$ wget http://s3.amazonaws.com/ec2metadata/ec2-metadata
$ chmod u+x ec2-metadata

Then some testing! To get the AMI-ID of the current instance

ec2-metadata -a
public-hostname: ec2-x-x-x-x.compute-1.amazonaws.com

To get the PUBLIC HOSTNAME of the current instance

ec2-metadata -p
public-hostname: ec2-x-x-x-x.compute-1.amazonaws.com

To get the LOCAL IPV4 ADDRESS of the current instance

ec2-metadata -o
public-hostname: ec2-x-x-x-x.compute-1.amazonaws.com

If you don’t want to install this useful tool, you can do it the hard way using wget queries like below…

Find out information about physical hardware

wget -q -O - http://169.254.169.254/latest/meta-data/metrics/vhostmd

Public hostname of the current instance

wget -q -O - http://169.254.169.254/latest/meta-data/public-hostname

0143440600