Instance metadata

Question 1

What is instance metadata?

Answer 1

Instance metadata is a service that AWS provides to instances. It is information about the instance that can be accessible from inside any instance.

Question 2

What is the main function of instance metadata?

Answer 2

Helps to manage or configure any running instance.

Question 3

On what address can you access instance metadata of any instance?

Answer 3

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

Question 4

What can you find in the instance metadata?

Answer 4

Meta-data contains information on the environment the instance is in.
You can find out about hostname, security groups, events, the networking or user-data among other things - information is divided into categories.

Question 5

Is the metadata of an instance encrypted or requires authentication to access it?

Answer 5

This is not authenticated or encrypted. Anyone who can gain access to the instance can see the meta-data. This can be restricted by local firewall

Question 6

What is the main thing that you need to consider when using instance metadata?

Answer 6

Treat the metadata as something that can get exposed.

Question 7

When is meta-data useful?

Answer 7

Meta-data can be useful when designing highly available or fault tolerant applications by understanding the environment and the topology they are running inside.
You want your application to spread in different AZs having a configuration and keeping it.
You can give the instance visibility of in which AZ it is in - very advantageous.