How to set an environment variable in Amazon EC2

Question

I created a tag on the AWS console for one of my EC2 instances.

However, when I look on the server, no such environment variable is set.

The same thing works with elastic beanstalk. env shows the tags I created on the console.

$ env

 [...]

 DB_PORT=5432

How can I set environment variables in Amazon EC2?

Answer 1

First, you have to retrieve information from the metadata and later you will be able to run your own set of environment commands.

So first, run this curl statement.

$curl http://169.254.169.254/latest/meta-data/instance-id

Then you can call the describe-tags using the pre-installed AWS CLI (or install it on your AMI) You can call describe-tags using your AWS CLI and if not pre-installed, install it.

aws ec2 describe-tags --filters "Name=resource-id,Values=i-5f4e3d2a" "Name=Value,Values=DB_PORT"

After this, you can use the Operating System’s set environment variable command.

export DB_PORT=/what/you/retrieved/from/the/previous/call

You can also check out this shell script which was written with the above instructions.

https://github.com/12moons/ec2-tags-env