Amazon EC2 - Retrieving Metadata

One can use tools like curl and wget to retrieve information from Amazon's metadata service to get information about an EC2 server you are sending the request from. This can be quite useful, as you may wish to write a script that may do different things based on the instance ID etc.

Steps

curl http://169.254.169.254/latest/meta-data/

That is the fixed IP from the docs. It does not need to be changed.

This will return a list of additional paths you can query to get the information you require. If it ends in a / then you know that it is a directory or additonal paths, and not a single piece of information to be returned (like instance-id).

ami-id
ami-launch-index
ami-manifest-path
block-device-mapping/
events/
hostname
identity-credentials/
instance-action
instance-id
instance-life-cycle
instance-type
local-hostname
local-ipv4
mac
metrics/
network/
placement/
profile
public-hostname
public-ipv4
public-keys/
reservation-id
security-groups
services/

IMDSv2

The examples above are straightforward and use IMDSv1. If you need to use IMDSv2, then you would do the following:

TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 3"` \
  && curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/meta-data/

However, bear in mind that doing so will change the response structure.

References

• AWS Docs - Retrieve instance metadata