AWS CLI Commands – A Comprehensive Guide

Alaric Bird

3 weeks ago

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Master AWS CLI with this comprehensive guide! Learn how to install, configure, and use AWS CLI commands for EC2, S3, IAM, Lambda, CloudFormation, and more. Boost efficiency with automation and best practices. #centlinux #linux #awsforbeginners

1. Introduction

AWS Command Line Interface (AWS CLI) is a powerful tool that allows users to manage AWS services through command-line commands. It simplifies cloud management by providing a direct way to interact with AWS resources without using the graphical AWS Management Console.

With AWS CLI, developers, system administrators, and cloud engineers can automate workflows, manage cloud resources, and execute commands efficiently. Whether you’re working with Amazon S3, EC2, IAM, Lambda, or other AWS services, AWS CLI provides an effective and scriptable way to streamline operations.

Why Use AWS CLI?

Automates repetitive cloud management tasks
Reduces the need for manual interaction with the AWS Console
Allows bulk operations using shell scripts
Provides programmatic access to AWS services

AWS CLI Commands – A Comprehensive Guide

2. What is AWS CLI?

AWS CLI is a command-line tool that interacts with AWS services using commands instead of a graphical interface. It is built on top of AWS SDKs and provides complete control over AWS services.

Key Features of AWS CLI

Supports multiple AWS services, including S3, EC2, IAM, Lambda, and more
Enables scripting and automation of AWS tasks
Works across Windows, macOS, and Linux
Supports AWS profiles for managing multiple accounts
Provides JSON-formatted output for easy parsing

AWS CLI vs. AWS Management Console

Feature	AWS CLI	AWS Management Console
User Interface	Command-line	Graphical UI
Automation	Supports scripting & automation	Limited automation features
Accessibility	Requires terminal knowledge	Easy for beginners
Bulk Operations	Easily managed via scripts	Requires manual input

Recommended Training: Ultimate AWS Certified Cloud Practitioner CLF-C02 2025 from Stephane Maarek

3. Installing AWS CLI

AWS CLI is available for Windows, macOS, and Linux. Follow the steps below to install it on your preferred platform.

Windows Installation

Download the AWS CLI MSI installer from the AWS website.
Run the installer and follow the setup wizard.
Verify the installation by running:

aws --version

macOS Installation

Install AWS CLI using Homebrew:

brew install awscli

Verify the installation:

aws --version

Linux Installation

Download the installer:

curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"

Unzip the installer:

unzip awscliv2.zip

Run the installation script:

sudo ./aws/install

Verify installation:

aws --version

Watch our video Tutorial to install AWS CLI on Linux:

4. Configuring AWS CLI

Before using AWS CLI, you need to configure it with your AWS credentials.

Setting Up AWS Credentials

Run the following command to configure AWS CLI:

aws configure

You will be prompted to enter:

AWS Access Key ID
AWS Secret Access Key
Default AWS Region
Output format (json, table, or text)

Managing Multiple AWS Profiles

You can configure multiple profiles for different AWS accounts:

aws configure --profile my-second-profile

To use a specific profile, run:

aws s3 ls --profile my-second-profile

5. AWS CLI Commands for Beginners

AWS CLI provides a wide range of commands for managing AWS services. Here are some essential commands to get started:

Listing S3 Buckets

aws s3 ls

This command lists all S3 buckets in your AWS account.

Uploading a File to S3

aws s3 cp myfile.txt s3://my-bucket/

Downloading a File from S3

aws s3 cp s3://my-bucket/myfile.txt .

Checking Running EC2 Instances

aws ec2 describe-instances

Creating a New IAM User

aws iam create-user --user-name newuser

These are just a few basic commands to get started with AWS CLI. Mastering these will help in managing AWS services efficiently.

6. Advanced AWS CLI Commands

As you get comfortable with AWS CLI basics, it’s time to explore more advanced commands that help manage AWS resources efficiently.

Managing EC2 Instances

AWS CLI allows you to start, stop, and terminate EC2 instances directly from the command line.

Start an EC2 instance:

aws ec2 start-instances --instance-ids i-0abcd1234efgh5678

Stop an EC2 instance:

aws ec2 stop-instances --instance-ids i-0abcd1234efgh5678

Terminate an EC2 instance:

aws ec2 terminate-instances --instance-ids i-0abcd1234efgh5678

Working with IAM Policies and Roles

List IAM policies

aws iam list-policies

Attach a policy to a user

aws iam attach-user-policy --user-name newuser --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess

Detach a policy from a user

aws iam detach-user-policy --user-name newuser --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess

Automating Tasks with AWS CLI Scripts

Using shell scripts, you can automate AWS operations like creating backups, managing EC2 instances, or rotating access keys.

Example: Script to Start All Stopped EC2 Instances

#!/bin/bash
aws ec2 describe-instances --query "Reservations[*].Instances[*].[InstanceId,State.Name]" --output text | awk '$2=="stopped"{print $1}' | while read instance; do
    aws ec2 start-instances --instance-ids $instance
done

7. Working with S3 Using AWS CLI

Amazon S3 (Simple Storage Service) is one of the most commonly used AWS services. AWS CLI makes it easy to manage S3 buckets and objects.

Creating and Deleting S3 Buckets

Create an S3 bucket

aws s3 mb s3://my-new-bucket

Delete an S3 bucket

aws s3 rb s3://my-old-bucket --force

Uploading and Downloading Files

Upload a file to an S3 bucket

aws s3 cp myfile.txt s3://my-bucket/

Download a file from an S3 bucket

aws s3 cp s3://my-bucket/myfile.txt .

Setting Permissions and Managing ACLs

Make a file publicly readable

aws s3api put-object-acl --bucket my-bucket --key myfile.txt --acl public-read

List permissions of a file

aws s3api get-object-acl --bucket my-bucket --key myfile.txt

8. Managing EC2 Instances with AWS CLI

EC2 (Elastic Compute Cloud) is a core AWS service for running virtual machines. AWS CLI allows you to efficiently manage EC2 instances.

Launching a New EC2 Instance

aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro --key-name MyKeyPair --security-groups MySecurityGroup

Viewing and Modifying Instance Details

Describe all running instances

aws ec2 describe-instances --query "Reservations[*].Instances[*].[InstanceId,State.Name,PublicIpAddress]"

Modify an instance type

aws ec2 modify-instance-attribute --instance-id i-0abcd1234efgh5678 --instance-type t3.micro

Stopping and Terminating Instances

Stop an instance

aws ec2 stop-instances --instance-ids i-0abcd1234efgh5678

Terminate an instance

aws ec2 terminate-instances --instance-ids i-0abcd1234efgh5678

9. Using AWS CLI for IAM Management

IAM (Identity and Access Management) is critical for securing AWS resources. AWS CLI provides full control over users, groups, and roles.

Creating and Managing IAM Users

Create a new IAM user

aws iam create-user --user-name newuser

Delete an IAM user

aws iam delete-user --user-name olduser

Assigning Roles and Permissions

Attach a policy to a user

aws iam attach-user-policy --user-name newuser --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess

List policies attached to a user

aws iam list-attached-user-policies --user-name newuser

Generating Security Credentials

Create an access key for a user

aws iam create-access-key --user-name newuser

Delete an access key

aws iam delete-access-key --access-key-id ABCDEFGHIJKLMNOPQRST --user-name newuser

10. Automating Tasks with AWS CLI and Scripts

Automation is one of the key advantages of AWS CLI. By using shell scripts, you can schedule and automate AWS tasks.

Writing Shell Scripts for Automation

Example: Auto Backup S3 Files to Another Bucket

#!/bin/bash
aws s3 sync s3://source-bucket/ s3://backup-bucket/

Scheduling Tasks with Cron Jobs

To automate AWS CLI tasks, use cron jobs on Linux/macOS:

0 2 * * * /path/to/myscript.sh

This will run the script every day at 2 AM.

Best Practices for AWS CLI Automation

Always use IAM roles instead of access keys
Encrypt sensitive data using AWS KMS
Use logging to track automation failures

11. Working with AWS Lambda Using AWS CLI

AWS Lambda lets you run code without managing servers. With AWS CLI, you can create, update, and invoke Lambda functions quickly.

Deploying a Lambda Function

To deploy a Lambda function, you first need a ZIP package containing your function’s code.

Create a ZIP file

zip function.zip index.js

Deploy the Lambda function

aws lambda create-function --function-name MyLambdaFunction --runtime nodejs14.x --role arn:aws:iam::123456789012:role/execution_role --handler index.handler --zip-file fileb://function.zip

Updating and Managing Lambda Configurations

Update Lambda function code

aws lambda update-function-code --function-name MyLambdaFunction --zip-file fileb://function.zip

Change Lambda memory size

aws lambda update-function-configuration --function-name MyLambdaFunction --memory-size 512

Invoking Functions from the Command Line

Invoke a Lambda function

aws lambda invoke --function-name MyLambdaFunction output.txt

Check Lambda logs

aws logs describe-log-streams --log-group-name /aws/lambda/MyLambdaFunction

12. AWS CLI and CloudFormation

AWS CloudFormation enables Infrastructure as Code (IaC). AWS CLI helps you create, update, and delete stacks efficiently.

Creating and Deploying CloudFormation Stacks

Create a new stack

aws cloudformation create-stack --stack-name MyStack --template-body file://template.json

List all stacks

aws cloudformation list-stacks

Updating and Managing Infrastructure as Code

Update an existing stack

aws cloudformation update-stack --stack-name MyStack --template-body file://updated-template.json

Rolling Back and Deleting CloudFormation Stacks

Rollback changes in case of failure

aws cloudformation rollback-stack --stack-name MyStack

Delete a stack

aws cloudformation delete-stack --stack-name MyStack

13. AWS CLI for Monitoring and Logging

AWS CLI can help monitor AWS resources and retrieve logs for troubleshooting.

Checking CloudWatch Metrics

List available metrics

aws cloudwatch list-metrics

Get CPU utilization of an EC2 instance

aws cloudwatch get-metric-statistics --metric-name CPUUtilization --namespace AWS/EC2 --statistics Average --dimensions Name=InstanceId,Value=i-0abcd1234efgh5678 --start-time 2024-01-01T00:00:00Z --end-time 2024-01-02T00:00:00Z --period 3600

Managing AWS Logs Using AWS CLI

List log groups

aws logs describe-log-groups

Retrieve recent log events

aws logs get-log-events --log-group-name /aws/lambda/MyLambdaFunction --log-stream-name latest

Setting Up Alerts and Notifications

Create a CloudWatch alarm

aws cloudwatch put-metric-alarm --alarm-name HighCPUUsage --metric-name CPUUtilization --namespace AWS/EC2 --statistic Average --period 300 --threshold 80 --comparison-operator GreaterThanThreshold --dimensions Name=InstanceId,Value=i-0abcd1234efgh5678 --evaluation-periods 2 --alarm-actions arn:aws:sns:us-east-1:123456789012:MyNotificationTopic

14. Security Best Practices for AWS CLI

Security is crucial when using AWS CLI. Follow these best practices to keep your AWS environment secure.

Using IAM Roles Instead of Access Keys

Avoid using static access keys and instead assign IAM roles to EC2 instances:

aws iam attach-role-policy --role-name MyRole --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess

Implementing Multi-Factor Authentication (MFA)

Enable MFA for users with sensitive permissions:

aws iam enable-mfa-device --user-name admin --serial-number arn:aws:iam::123456789012:mfa/admin-mfa --authentication-code-1 123456 --authentication-code-2 654321

Regularly Rotating Credentials

Rotate IAM access keys every 90 days:

aws iam create-access-key --user-name developer
aws iam delete-access-key --access-key-id OLD_ACCESS_KEY_ID --user-name developer

15. Troubleshooting AWS CLI Issues

Even with proper configuration, AWS CLI issues may arise. Here’s how to troubleshoot common problems.

Common Errors and How to Fix Them

Invalid credentials error

aws configure

Reconfigure AWS CLI and ensure your credentials are correct.

Command not found error

aws --version

Ensure AWS CLI is installed properly.

Debugging AWS CLI Commands

Enable debugging mode:

aws s3 ls --debug

Where to Find AWS CLI Logs

AWS CLI logs errors and API calls. Check logs for debugging:

cat ~/.aws/cli/cache/*.json

16. Conclusion

AWS CLI is an essential tool for managing AWS services efficiently. Whether you’re handling EC2 instances, automating S3 backups, deploying Lambda functions, or monitoring CloudWatch metrics, AWS CLI streamlines cloud management with powerful commands and scripting capabilities.

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By mastering AWS CLI, you can:

Automate repetitive cloud tasks
Improve security with IAM role-based access
Enhance infrastructure management with CloudFormation
Optimize monitoring and logging with CloudWatch

Start using AWS CLI today and take control of your cloud environment like a pro!

17. FAQs

1. How do I update AWS CLI to the latest version?

To update AWS CLI, use the following command:

Windows:

aws --version # Check version 
msiexec.exe /i https://awscli.amazonaws.com/AWSCLIV2.msi

macOS (Homebrew):

brew upgrade awscli

Linux:

sudo curl -s "https://awscli.amazonaws.com/AWSCLIV2.pkg" -o "awscliv2.pkg" 
sudo installer -pkg awscliv2.pkg -target /

2. Can I use AWS CLI without configuring credentials?

Yes, you can use AWS CLI without manually configuring credentials by using IAM roles. Attach an IAM role to your EC2 instance to grant necessary permissions automatically.

3. How can I switch between multiple AWS accounts in AWS CLI?

Use AWS CLI profiles to manage multiple accounts:

aws configure --profile my-second-account
aws s3 ls --profile my-second-account

4. What are the best alternatives to AWS CLI?

Alternatives to AWS CLI include:

AWS SDKs (Python, Java, Go)
AWS Tools for PowerShell
AWS CDK (Cloud Development Kit)

5. Does AWS CLI support automation for all AWS services?

Most AWS services are supported, but some advanced configurations may require AWS SDKs or CloudFormation. Check the official AWS CLI documentation for full service compatibility.

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