AWS - My Findings ​

📚 Cheatsheet ​

Services ​

EC2 (Elastic Compute Cloud) ​

• Provide remote/cloud servers
• You can enable SSH login from "Security Group". There is source IP field where you can specify your IP address, Generally it's default to 0.0.0.0/0 which means anyone can access your server. If you want to only allow your IP address to access the server, you can specify your IP address in this field.
• Default username for Amazon Linux is ec2-user

SES (Simple Email Service) ​

• Used to send emails. You can also send emails in bulk.
• You can verify your domain and email address in SES. You can only send emails from verified domain and email address.

CloudWatch ​

Alarms ​

If you want to set email alerts for lambda fails. Here's best config I'm aware of:

• Period: 15 minutes or 1 minute (select based on your requirement)
• Statistic: Sum
• Metric: Errors
• Conditions: Greater than 0
• Notification: Select SNS topic to send email alerts

DynamoDB ​

Querying ​

• At most you can query 2 cols, partition key and sort key. If you want to query more than 2 cols, you have to use scan which is not recommended for large datasets. Instead prefer RDS if you have more tables like these.

S3 ​

• When you upload file with same key in S3, it will overwrite the existing file with new file.

Lambda ​

Logging ​

Use below logging setup to get clean logs in CloudWatch:

import logging 

# Logging Setup
logger = logging.getLogger()
logger.handlers = []  # remove pre-configured handlers
handler = logging.StreamHandler(sys.stdout)
handler.setFormatter(logging.Formatter("[%(levelname)s] %(message)s")) # Remove datetime as cloudwatch already adds that
logger.addHandler(handler)
logger.setLevel(logging.INFO)

def lambda_handler(event: dict[str, Any], context: Any) -> None:
    logger.info("Event: %s", event)

✨ Tips ​

• Use CloudFormation to deploy your AWS resources. It allows you to define your infrastructure as code, making it easier to manage and version control.
• Prefer layer_<layer_name> for Lambda layers. It helps in identifying from which layer the function is using the code.
• Always use cloudformation with versioning to setup your AWS resources. It allows you to track changes and roll back if needed.
  • Use cloudformation designer & related tool to visualize your AWS infra.
• Enable AWS Cost Anomaly Detection to monitor your spending and receive alerts for unusual spending patterns. Generally, I prefer 10% threshold on AWS account.