AWS CLI Setup

Why Use the AWS CLI?

While the AWS Console (web interface) is great for exploration, the CLI is essential for:

• Automation - script deployments, backups, and maintenance
• Speed - many operations are faster from the terminal
• Reproducibility - commands can be saved and repeated
• AI-assisted workflows - Claude Code can run AWS commands for you

Step 1: Install AWS CLI

Step 2: Configure AWS CLI

Now we'll connect the CLI to your AWS account using the access keys you created in the previous lesson.

2.1 Run the Configuration Wizard

bash
Copy
aws configure

You'll be prompted for four pieces of information:

2.2 Enter Your Credentials

AWS Access Key ID [None]: AKIAIOSFODNN7EXAMPLE
AWS Secret Access Key [None]: wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
Default region name [None]: us-east-1
Default output format [None]: json

2.3 Choose Your Region

Pick a region close to you or your users:

Step 3: Verify Your Configuration

3.1 Check Your Identity

bash
Copy
aws sts get-caller-identity

You should see something like:

json
Copy
{
    "UserId": "AIDAIOSFODNN7EXAMPLE",
    "Account": "123456789012",
    "Arn": "arn:aws:iam::123456789012:user/admin"
}

This confirms the CLI is authenticated and shows which user you're acting as.

3.2 List S3 Buckets (Simple Test)

bash
Copy
aws s3 ls

If you have no buckets, you'll see no output (that's fine!). If you see an error, something is wrong with your credentials.

3.3 Check Your Region

bash
Copy
aws configure get region

Should output your chosen region (e.g., us-east-1).

Step 4: Understanding Configuration Files

The AWS CLI stores your credentials in two files:

Step 5: Multiple Profiles (Optional)

If you have multiple AWS accounts (personal, work, different projects), use named profiles:

Create a Named Profile

bash
Copy
aws configure --profile work

Enter credentials for your work account.

Use a Named Profile

bash
Copy
# Specify profile per-command
aws s3 ls --profile work

# Or set for your entire session
export AWS_PROFILE=work   # Linux/macOS
$env:AWS_PROFILE="work"   # Windows PowerShell

List Configured Profiles

bash
Copy
aws configure list-profiles

Common CLI Commands Quick Reference

Now that you're set up, here are some useful commands:

bash
Copy
# Get help for any command
aws help
aws s3 help
aws ec2 describe-instances help

# List resources
aws s3 ls                          # List S3 buckets
aws ec2 describe-instances         # List EC2 instances
aws ecr describe-repositories      # List container registries

# Get account info
aws sts get-caller-identity        # Who am I?
aws iam list-users                 # List IAM users

# Check service quotas
aws service-quotas list-service-quotas --service-code ec2

Troubleshooting

"Unable to locate credentials"

bash
Copy
# Check if credentials file exists
ls -la ~/.aws/credentials

# Reconfigure if needed
aws configure

"Access Denied" Errors

Your IAM user may lack permissions. Check:

1. You're using the correct profile
2. Your IAM user has the required policies attached
3. You're operating in the correct region

bash
Copy
# Verify which identity you're using
aws sts get-caller-identity

"Region is missing"

bash
Copy
# Set your default region
aws configure set region us-east-1

# Or specify per-command
aws ec2 describe-instances --region us-west-2

Clock Skew Errors

AWS requires your system clock to be accurate. Fix with:

What's Next?

Your AWS CLI is now configured and ready. In the next lesson, we'll learn about AWS core concepts like regions, services, and how everything fits together before we deploy our first application.