Getting AWS EC2 instance id (instanceid) from within the ec2 instance

In general you can get a lot of instance metadata by accessing API on
http://169.254.169.254/latest/meta-data/
That includes instance id.

On generic Linux system, you can get the ID either using curl:
curl http://169.254.169.254/latest/meta-data/instance-id
or wget:
wget -q -O - http://169.254.169.254/latest/meta-data/instance-id

If you instance is based on Amazon Linux or have cloud-utils installed you can also run:
ec2-metadata -i
for instance id.

more documentation on metadata is a available here:
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html

Provided by:Forthscale systems, cloud experts