Want to control your AWS cloud like a pro? The AWS CLI is your ultimate command-line weapon—fast, flexible, and fully automated. Let’s dive into how you can master it in no time.
What Is AWS CLI and Why It Matters
The AWS Command Line Interface (CLI) is a powerful tool that allows developers, system administrators, and DevOps engineers to interact with Amazon Web Services directly from a terminal or script. Instead of navigating through the AWS Management Console with a mouse, you can use text-based commands to manage services like EC2, S3, Lambda, and more—saving time and enabling automation.
Unlike the graphical interface, the AWS CLI provides a consistent, scriptable environment across operating systems (Windows, macOS, Linux). This makes it ideal for integrating into CI/CD pipelines, infrastructure-as-code workflows, and large-scale cloud management tasks. Whether you’re launching a server, uploading files, or configuring security groups, the AWS CLI streamlines everything into concise, repeatable commands.
Core Features of AWS CLI
The AWS CLI isn’t just about typing commands—it’s about unlocking efficiency and precision in cloud operations. Its core features make it indispensable for modern cloud workflows.
- Unified Interface: One tool to manage over 200 AWS services.
- Automation Ready: Easily script repetitive tasks using shell scripts or programming languages.
- JSON Output Support: Structured responses make parsing and integration with other tools seamless.
- Configurable Profiles: Manage multiple AWS accounts and roles without switching credentials manually.
These capabilities empower teams to move faster, reduce human error, and maintain consistency across environments.
How AWS CLI Compares to AWS Console and SDKs
While the AWS Management Console offers a user-friendly GUI, it’s limited when dealing with bulk operations or automation. For example, launching 50 EC2 instances via the console requires clicking through wizards repeatedly. With the AWS CLI, you can do it with a single looped command.
On the other hand, AWS SDKs (like boto3 for Python) are great for embedding AWS functionality into applications. However, they require writing full programs. The AWS CLI strikes the perfect balance—offering immediate interactivity without the overhead of coding entire apps.
“The AWS CLI is the Swiss Army knife of cloud management—simple enough for beginners, powerful enough for experts.” — AWS Certified Solutions Architect
Installing and Configuring AWS CLI
Before you can start using the AWS CLI, you need to install and configure it properly. This process varies slightly depending on your operating system, but the end goal is the same: have a working CLI tool authenticated with your AWS account.
The AWS CLI comes in two versions: v1 and v2. AWS recommends using AWS CLI v2 because it includes built-in support for AWS Single Sign-On (SSO), better error messages, and automatic prompt detection. Version 1 is still supported but lacks some modern features.
Step-by-Step Installation Guide
Here’s how to install AWS CLI v2 on popular platforms:
- macOS: Use Homebrew with
brew install awsclior download the bundled installer from the official AWS documentation. - Windows: Download the MSI installer from AWS’s website and run it. It automatically adds the CLI to your PATH.
- Linux: Use the bundled installer script:
curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
Unzip and run the install script as per AWS guidelines.
After installation, verify it works by running aws --version. You should see output showing the CLI version, Python version, and OS.
Configuring AWS CLI with IAM Credentials
To authenticate the AWS CLI with your AWS account, you need valid credentials. These typically come from an IAM user with appropriate permissions.
Run aws configure and provide the following:
- AWS Access Key ID
- AWS Secret Access Key
- Default region name (e.g.,
us-east-1) - Default output format (
json,text, ortable)
These credentials are stored in ~/.aws/credentials, while the region and output format go into ~/.aws/config. Never commit these files to version control!
You can also use temporary credentials via IAM roles or AWS SSO, especially useful in enterprise environments where long-term keys aren’t allowed.
Essential AWS CLI Commands for Daily Use
Once configured, you can start using the AWS CLI to manage your cloud resources. Here are some of the most commonly used commands across key AWS services.
Each AWS service has its own namespace in the CLI. For example, aws s3 controls Amazon S3, aws ec2 manages EC2 instances, and aws iam handles identity and access management.
Managing EC2 Instances with AWS CLI
Amazon Elastic Compute Cloud (EC2) is one of the most widely used AWS services. The AWS CLI lets you launch, stop, terminate, and monitor instances programmatically.
- Launch an instance:
aws ec2 run-instances --image-id ami-0abcdef1234567890 --instance-type t3.micro --key-name MyKeyPair --security-group-ids sg-903004f8 --subnet-id subnet-6e7f829e - Stop an instance:
aws ec2 stop-instances --instance-ids i-1234567890abcdef0 - Terminate an instance:
aws ec2 terminate-instances --instance-ids i-1234567890abcdef0 - List running instances:
aws ec2 describe-instances --filters "Name=instance-state-name,Values=running"
You can filter results using JMESPath queries to extract specific fields, making it easier to parse large JSON outputs.
Working with S3 Buckets and Objects
Amazon S3 is the backbone of cloud storage. The AWS CLI provides two ways to interact with S3: high-level s3 commands and low-level s3api commands.
- Create a bucket:
aws s3 mb s3://my-unique-bucket-name - Upload a file:
aws s3 cp local-file.txt s3://my-bucket/ - Download a file:
aws s3 cp s3://my-bucket/remote-file.txt . - Synchronize a folder:
aws s3 sync ./local-folder s3://my-bucket/backup/ - List bucket contents:
aws s3 ls s3://my-bucket --recursive
The sync command is particularly powerful—it only transfers changed files, making it ideal for backups and deployments.
“Using
aws s3 syncsaved our team over 10 hours per week in manual uploads.” — DevOps Lead, Tech Startup
Advanced AWS CLI Techniques for Power Users
Once you’re comfortable with basic commands, it’s time to level up. The AWS CLI supports advanced features that enable complex automation, secure access, and efficient troubleshooting.
These techniques are used daily by cloud engineers and architects to manage large-scale infrastructures with minimal effort.
Using JMESPath for Querying and Filtering Output
By default, AWS CLI commands return JSON data. When dealing with large responses (like listing hundreds of S3 objects), parsing this data manually is impractical.
JMESPath is a query language built into the AWS CLI that allows you to filter and format JSON output. You use it with the --query parameter.
- Get only instance IDs:
aws ec2 describe-instances --query "Reservations[*].Instances[*].InstanceId" --output table - Filter running instances in a specific AZ:
aws ec2 describe-instances --query "Reservations[*].Instances[?State.Name=='running' && Placement.AvailabilityZone=='us-east-1a'].InstanceId" - Extract public IPs of all running instances:
aws ec2 describe-instances --query "Reservations[*].Instances[?State.Name=='running'].PublicIpAddress" --output text
JMESPath supports functions like length(), sort(), and join(), giving you full control over how data is presented.
Leveraging AWS CLI with Shell Scripts
One of the biggest advantages of the AWS CLI is its compatibility with shell scripting. You can combine CLI commands with bash logic to automate entire workflows.
For example, here’s a simple script that backs up logs to S3 daily:
#!/bin/bash
DATE=$(date +%Y%m%d)
aws s3 cp /var/log/app.log s3://my-logs-backup/app-$DATE.log
if [ $? -eq 0 ]; then
echo "Backup successful"
else
echo "Backup failed" >&2
fiYou can schedule this with cron or integrate it into deployment pipelines. More complex scripts can check resource states, trigger alerts, or scale infrastructure based on demand.
Managing Multiple AWS Accounts and Roles
In real-world scenarios, organizations often use multiple AWS accounts—for development, staging, production, billing, etc. The AWS CLI makes it easy to switch between them securely.
Instead of hardcoding credentials, you can define named profiles in your AWS configuration. Each profile can point to a different account or role.
Setting Up Named Profiles
To create a new profile, run:aws configure --profile dev
This will prompt you for access key, secret, region, and output format—just like the default setup. The credentials are saved under the dev profile.
To use it, append --profile dev to any command:aws s3 ls s3://my-bucket --profile dev
You can list all configured profiles by checking the ~/.aws/credentials file or using third-party tools.
Assuming IAM Roles Across Accounts
For enhanced security, many companies avoid long-term access keys. Instead, users assume IAM roles that grant temporary credentials.
You can configure the AWS CLI to automatically assume a role using the role_arn and source_profile settings in ~/.aws/config:
[profile production] role_arn = arn:aws:iam::123456789012:role/AdminRole source_profile = dev region = us-east-1
Now, when you run aws --profile production s3 ls, the CLI will automatically request temporary credentials by assuming the specified role from the dev profile.
“Cross-account role assumption via AWS CLI reduced our security risks and simplified access management.” — Cloud Security Engineer
Best Practices for Secure and Efficient AWS CLI Usage
While the AWS CLI is incredibly powerful, misuse can lead to security vulnerabilities, cost overruns, or accidental deletions. Following best practices ensures safe and efficient operations.
These guidelines are followed by top-tier cloud teams and are aligned with AWS Well-Architected Framework principles.
Secure Handling of Credentials
Never embed AWS credentials directly in scripts or configuration files that are shared or stored in repositories. Use IAM roles, temporary tokens, or credential management tools like AWS SSO or HashiCorp Vault.
Enable multi-factor authentication (MFA) for IAM users who generate access keys. Rotate access keys regularly and disable unused ones.
Use the principle of least privilege: grant only the permissions necessary for a task. For example, a backup script should only have s3:PutObject and s3:ListBucket permissions—not full S3 access.
Use Dry Runs and Verbose Logging
Before executing destructive commands (like terminate-instances or delete-bucket), test them with filters or use services that support dry runs.
While not all AWS CLI commands support a native --dry-run flag, many do (e.g., EC2 actions). Always check the documentation.
Use --debug to see detailed logs of what the CLI is doing under the hood. This helps troubleshoot authentication issues, latency problems, or unexpected behavior.
Integrating AWS CLI with DevOps and Automation Tools
The true power of the AWS CLI shines when integrated into broader automation ecosystems. From CI/CD pipelines to infrastructure provisioning, it acts as a bridge between code and cloud.
Modern DevOps practices rely heavily on tools like Jenkins, GitHub Actions, Terraform, and Ansible—all of which can invoke the AWS CLI to deploy and manage resources.
Using AWS CLI in CI/CD Pipelines
In a typical CI/CD workflow, after code is tested, the AWS CLI can deploy artifacts to S3, update Lambda functions, or invalidate CloudFront caches.
Example GitHub Actions step:
- name: Deploy to S3
run: |
aws s3 sync build/ s3://my-website-prod --delete
aws cloudfront create-invalidation --distribution-id E123456789 --paths "/*"
Credentials are securely injected via GitHub Secrets or OIDC federated access, eliminating the need to store keys in the repo.
Combining AWS CLI with Infrastructure as Code (IaC)
While tools like Terraform and AWS CloudFormation manage infrastructure declaratively, the AWS CLI complements them by handling tasks outside their scope.
For example:
- After Terraform applies a change, use
aws ec2 describe-instancesto verify instance count. - Use
aws ssm send-commandto run scripts on EC2 instances provisioned by CloudFormation. - Trigger Lambda functions during deployment using
aws lambda invoke.
This hybrid approach gives you both structure and flexibility.
Troubleshooting Common AWS CLI Issues
Even experienced users encounter issues with the AWS CLI. Understanding common problems and how to fix them can save hours of frustration.
Most errors stem from misconfiguration, permission issues, or network problems.
Authentication and Permission Errors
If you see errors like Unable to locate credentials or AccessDenied, check the following:
- Are credentials set via
aws configure? - Is the correct profile being used (
--profile)? - Does the IAM user or role have the required permissions?
- Are temporary credentials expired?
Use aws sts get-caller-identity to verify which identity you’re currently using.
Region and Service Availability Problems
Some AWS services aren’t available in all regions. If a command fails with Unknown endpoint, confirm that:
- The service is supported in your configured region.
- You’ve specified the correct region using
--regionor default settings. - DNS resolution and internet connectivity are working.
You can list available regions with aws ec2 describe-regions.
What is AWS CLI used for?
The AWS CLI is used to manage Amazon Web Services from the command line. It allows users to control EC2 instances, S3 buckets, Lambda functions, and hundreds of other AWS services using simple commands, enabling automation, scripting, and integration into DevOps workflows.
How do I install AWS CLI on Windows?
Download the MSI installer from the official AWS website, run it, and follow the prompts. After installation, open Command Prompt or PowerShell and run aws --version to verify. Then configure it with aws configure using your IAM credentials.
Can I use AWS CLI with MFA?
Yes, you can use AWS CLI with Multi-Factor Authentication (MFA) by assuming IAM roles that require MFA. You’ll need to include the MFA token code when requesting temporary credentials via the AWS Security Token Service (STS).
How do I switch between AWS accounts using CLI?
Use named profiles in the AWS CLI configuration. Set up each account as a separate profile with aws configure --profile profile-name, then switch between them using the --profile flag in commands.
Is AWS CLI free to use?
Yes, the AWS CLI itself is free to download and use. However, any AWS resources you create or interact with (like EC2 instances or S3 storage) are subject to standard AWS pricing.
Mastering the AWS CLI is a game-changer for anyone working in the AWS ecosystem. From basic resource management to advanced automation, it provides unmatched control and efficiency. By installing it correctly, securing your credentials, leveraging scripting and profiles, and integrating it into your DevOps pipeline, you unlock the full potential of the cloud. Whether you’re a beginner or a seasoned pro, continuous learning and adherence to best practices will keep your workflows fast, secure, and reliable.
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