Say what just happened

Learn

The mental model

You've now made two real API calls. Before moving on to storage, networking and messaging, think through what happens between pressing Run and seeing JSON: what the CLI sends, what it signs the request with, and who answers.

This step isn't a command: answer the questions below.

Your task

Feedback Report a problem

You ran two commands and got JSON back both times. Answer the questions below: this is the mental model the rest of the cloud builds on.

What does the AWS CLI actually do when you run a command?It logs in to the AWS console and clicks the buttons for youIt sends a signed HTTPS request to the service's API and prints the JSON replyIt runs the command on a server in your AWS account

What does the CLI sign each request with?Your credentials: AWS checks the signature to know who's callingA password you type for every commandNothing: AWS trusts requests from the CLI

Interview prep

Every cloud screen starts by confirming you can actually reach the account.

What does aws sts get-caller-identity tell you, and when would you reach for it?

It returns the account id, user id, and ARN of whoever the current credentials belong to — the cloud equivalent of whoami. It's the first thing to run when a command is mysteriously denied or hitting the wrong account: it confirms which identity and account you're actually authenticated as.

Say what just happened

The mental model

Your task

Interview prep

Output