AWS CLI & SDK – Automating AWS Like a Pro

Managing AWS via the web console is great for learning, but serious professionals use automation tools like the AWS Command Line Interface (CLI) and SDKs (Software Development Kits) to streamline workflows, deploy applications, and interact programmatically with AWS services.

🧑‍💻 What is AWS CLI?

AWS CLI is a unified tool to manage AWS services via terminal/command line. It supports all major services and can run commands from a local computer, a remote server, or a CI/CD pipeline.

📌 Ideal for automation, scripting, and DevOps tasks.

💻 Installing AWS CLI

✅ For Windows:

• Download the .msi installer from the official AWS CLI page

✅ For macOS:

brew install awscli

brew install awscli

✅ For Linux:

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

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

🔐 Configuring AWS CLI

After installation, run:

aws configure

aws configure

You’ll be prompted to enter:

• AWS Access Key ID
• AWS Secret Access Key
• Default Region (e.g., us-east-1)
• Output Format (json, table, or text)

🔒 Tip: Never hard-code these keys in scripts. Use environment variables or IAM roles for security.

⚙️ AWS CLI Basics – Real Examples

✅ List all S3 buckets:

aws s3 ls

aws s3 ls

✅ Upload a file to S3:

aws s3 cp hello.txt s3://my-bucket-name/

aws s3 cp hello.txt s3://my-bucket-name/

✅ Launch an EC2 instance:

aws ec2 run-instances \
  --image-id ami-0abcdef1234567890 \
  --count 1 \
  --instance-type t2.micro \
  --key-name MyKeyPair \
  --security-groups MySecurityGroup

aws ec2 run-instances \
  --image-id ami-0abcdef1234567890 \
  --count 1 \
  --instance-type t2.micro \
  --key-name MyKeyPair \
  --security-groups MySecurityGroup

✅ Create a new IAM user:

aws iam create-user --user-name newadmin

aws iam create-user --user-name newadmin

📂 CLI Output Formats

Choose between:

• json – best for parsing programmatically
• table – human-readable
• text – compact, script-friendly

Example:

aws ec2 describe-instances --output table

aws ec2 describe-instances --output table

🛡️ AWS CLI Profiles for Multi-Account Management

Use named profiles when working with multiple AWS accounts.

aws configure --profile prod-account

aws configure --profile prod-account

Call with:

aws s3 ls --profile prod-account

aws s3 ls --profile prod-account

🧰 AWS SDK – Write Code That Talks to AWS

The AWS SDK allows developers to integrate AWS directly into their applications using languages like Python, JavaScript, Java, PHP, and Go.

🔶 SDK for Python (Boto3)

✅ Installation:

pip install boto3

pip install boto3

✅ Basic S3 Upload:

import boto3

s3 = boto3.client('s3')
s3.upload_file('local.jpg', 'my-bucket', 'images/local.jpg')

import boto3

s3 = boto3.client('s3')
s3.upload_file('local.jpg', 'my-bucket', 'images/local.jpg')

✅ EC2 Instance Listing:

ec2 = boto3.client('ec2')
response = ec2.describe_instances()

for reservation in response['Reservations']:
    for instance in reservation['Instances']:
        print(instance['InstanceId'], instance['State']['Name'])

ec2 = boto3.client('ec2')
response = ec2.describe_instances()

for reservation in response['Reservations']:
    for instance in reservation['Instances']:
        print(instance['InstanceId'], instance['State']['Name'])

🟢 SDK for JavaScript (Node.js)

✅ Installation:

npm install aws-sdk

npm install aws-sdk

✅ Upload to S3:

const AWS = require('aws-sdk');
const fs = require('fs');

const s3 = new AWS.S3();

const uploadParams = {
  Bucket: 'my-bucket',
  Key: 'file.txt',
  Body: fs.createReadStream('file.txt'),
};

s3.upload(uploadParams, function(err, data) {
  if (err) console.log("Error", err);
  else console.log("Upload Success", data.Location);
});

const AWS = require('aws-sdk');
const fs = require('fs');

const s3 = new AWS.S3();

const uploadParams = {
  Bucket: 'my-bucket',
  Key: 'file.txt',
  Body: fs.createReadStream('file.txt'),
};

s3.upload(uploadParams, function(err, data) {
  if (err) console.log("Error", err);
  else console.log("Upload Success", data.Location);
});

When to Use CLI vs SDK?

Real-World Scenarios

🛡️ CLI & SDK Security Tips

• Use IAM roles for EC2 or Lambda instead of hardcoding keys
• Store credentials securely using AWS Secrets Manager
• Rotate credentials regularly
• Never commit .aws/credentials or .env files to GitHub
• Use least privilege principle in IAM policies

📊 Monitoring and Troubleshooting

• Use --debug flag to troubleshoot CLI commands
• Enable CloudTrail to log all CLI and SDK calls
• Monitor usage with CloudWatch Metrics

📌 Summary