Day - 9 | aWS CLI

Getting Started with AWS CLI (Command Line Interface)

As part of my cloud learning journey, I recently explored the AWS Command Line Interface (AWS CLI). AWS CLI is a powerful tool that allows us to interact with AWS services directly from the terminal, making cloud operations faster, repeatable, and automation-friendly.

In this blog, I’ll share my understanding of AWS CLI, how to set it up, and how it helps in real-world cloud and DevOps workflows.

🚀 What is AWS CLI?

AWS CLI is a unified command-line tool provided by Amazon Web Services that enables users to manage AWS services using commands instead of the AWS Management Console.

With AWS CLI, you can:

• Create and manage AWS resources

• Automate repetitive cloud tasks

• Integrate AWS operations into scripts and CI/CD pipelines

It is widely used by Cloud Engineers, DevOps Engineers, and SREs.

🧩 Why Use AWS CLI?

Some key benefits of AWS CLI include:

• Automation – Execute repetitive tasks using scripts

• Speed – Faster than navigating the AWS Console

• Consistency – Same commands across environments

• Integration – Works well with shell scripts and CI/CD tools

🛠️ Installing AWS CLI

🔹 On Linux / Ubuntu

sudo apt update
sudo apt install awscli -y

🔹 On Windows

• Download the AWS CLI MSI installer from the AWS official website

• Complete the installation wizard

Verify installation:

aws --version

🔐 Configuring AWS CLI

Before using AWS CLI, it must be configured with AWS credentials.

aws configure

You will be prompted to enter:

• AWS Access Key ID

• AWS Secret Access Key

• Default region name (e.g., us-east-1)

• Default output format (json)

These credentials are stored securely in the local system.

📦 Basic AWS CLI Commands

🔹 List S3 Buckets

aws s3 ls

🔹 Upload File to S3

aws s3 cp file.txt s3://bucket-name/

🔹 Download File from S3

aws s3 cp s3://bucket-name/file.txt ./

Create EC2

aws ec2 run-instances \
  --image-id ami-0ecb62995f68bb549 \
  --instance-type t3.micro \
  --key-name monukey \
  --security-group-ids sg-0e36b8cde65590a72 \
  --subnet-id subnet-09c4fc6e15071b5ac \
  --associate-public-ip-address \
  --region us-east-1 \
  --count 1 \
  --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=EC2-CLI-Demo}]'

List EC2 Instances

aws ec2 describe-instances

🔹 List IAM Users

aws iam list-users

🔄 AWS CLI vs AWS Console

Both are useful, but AWS CLI is preferred for automation and large-scale operations.

🧠 Real-World Use Cases

• Automating EC2 start/stop operations

• Uploading application logs to S3

• Managing infrastructure in CI/CD pipelines

• Performing bulk operations across AWS services

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🔐 Security Best Practices

• Never expose AWS credentials publicly

• Use IAM Roles instead of access keys on EC2

• Grant least privilege permissions

• Rotate access keys regularly