CLI scripting basics in AWS - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What is the output of this AWS CLI command?

You run the following AWS CLI command to list all S3 buckets in your account:

aws s3api list-buckets --query 'Buckets[].Name' --output text

What will be the output format?

A A newline-separated list of bucket names in plain text.

B A JSON array of bucket names.

C A table with bucket names and creation dates.

D An error because --output text is invalid here.

💡 Hint

Think about what the --output text option does in AWS CLI.

The --output text option formats the output as plain text, and the query selects only the bucket names, so the result is a tab-separated list of bucket names.

❓ Configuration

intermediate

Which AWS CLI command sets the default region for future commands?

You want to configure your AWS CLI so that all future commands use the region us-west-2 by default. Which command achieves this?

A aws configure region us-west-2

B aws set region us-west-2

C aws configure set region us-west-2

D aws configure default-region us-west-2

💡 Hint

The AWS CLI uses the configure set command to change settings.

The correct syntax to set the default region is 'aws configure set region us-west-2'.

❓ security

advanced

What error occurs when running this AWS CLI command without permissions?

You run this command to list EC2 instances:

aws ec2 describe-instances

Your IAM user does not have permission to describe instances. What error message will you see?

A A ResourceNotFoundException error because no instances exist.

B No error; the command returns an empty list.

C A SyntaxError due to incorrect command syntax.

D An AccessDeniedException error indicating lack of permissions.

💡 Hint

Think about what happens when you lack permissions to perform an AWS action.

AWS returns an AccessDeniedException error when the user lacks permissions for the requested action.

❓ Architecture

advanced

Which AWS CLI command sequence correctly creates and tags an EC2 instance?

You want to create an EC2 instance and then add a Name tag to it using AWS CLI. Which sequence of commands is correct?

A

1) aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro
2) aws ec2 create-tags --resources <instance-id> --tags Key=Name,Value=MyInstance

B

1) aws ec2 create-tags --resources <instance-id> --tags Key=Name,Value=MyInstance
2) aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro

C 1) aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro --tag Name=MyInstance

D 1) aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro --tags Key=Name,Value=MyInstance

💡 Hint

Creating tags requires the instance ID, which you get after launching the instance.

You first launch the instance, then use its ID to create tags. The run-instances command does not accept a --tag or --tags parameter directly.

✅ Best Practice

expert

What is the best practice to securely run AWS CLI commands in automated scripts?

You want to run AWS CLI commands in an automated script on a server. Which approach is best to securely provide credentials?

A Store AWS access keys directly in the script as plain text variables.

B Use IAM roles attached to the server or instance to provide temporary credentials.

C Manually enter AWS credentials each time the script runs.

D Store AWS credentials in a publicly accessible file on the server.

💡 Hint

Think about avoiding hardcoding secrets and using AWS features for security.

Using IAM roles attached to the server or instance provides temporary credentials automatically and avoids exposing secrets in code or files.