การนำแอปพลิเคชัน SAM ไปใช้งาน

Welcome to deploying SAM applications! The AWS Serverless Application Model Command Line Interface (SAM CLI) is your best friend for building and managing serverless projects.

It extends AWS CloudFormation to simplify defining serverless resources. The SAM CLI provides commands to build, test, and deploy your serverless applications.

Before deploying, your SAM application needs to be built. The sam build command takes your application code and dependencies, then prepares them for deployment.

• It packages dependencies (e.g., Python libraries).
• It transpiles code if needed (e.g., TypeScript to JavaScript).
• It creates a deployable artifact in a .aws-sam/build directory.

Let's look at a simple Python Lambda function and its template.yaml. The sam build command processes this to create deployable code.

After running sam build, the packaged code would be ready for local testing or deployment.

The SAM CLI allows you to test your Lambda functions locally without deploying them to AWS, saving time and costs. Use sam local invoke to simulate a Lambda invocation.

You can pass event data directly to your function, just like how AWS services (like API Gateway or S3) would trigger it.

To test the Lambda function from the previous scene, you'd use sam local invoke with the logical ID of your function and an event file.

For example, sam local invoke MyHelloWorldFunction --event event.json would test a function named 'MyHelloWorldFunction' using the data in event.json.

If your SAM application includes an API Gateway, you can simulate the entire API locally using sam local start-api. This command starts a local web server that mimics API Gateway.

You can then send HTTP requests to http://127.0.0.1:3000 and test your API endpoints end-to-end, locally.

Once your application is built and tested locally, you're ready to deploy it to AWS. The sam deploy command is used for this.

It packages your application artifacts, uploads them to an S3 bucket, and then uses AWS CloudFormation to deploy your serverless resources.

For your first deployment, using the --guided flag is highly recommended. It will walk you through setting up necessary parameters interactively.

• Stack Name: Unique identifier for your CloudFormation stack.
• AWS Region: Where to deploy your resources.
• S3 Bucket: For storing deployment artifacts.
• Capabilities: Acknowledging IAM resource creation.

Example: sam deploy --guided

In real-world scenarios, you'll often have development, staging, and production environments. SAM CLI helps manage this by allowing you to specify different stack names and parameters.

• Use distinct Stack Names (e.g., my-app-dev, my-app-prod).
• Use --parameter-overrides to pass different values for environment-specific configurations (e.g., database names, API keys).

Which SAM CLI command is used to test your API Gateway endpoints locally?

Congratulations! You've learned the essential steps for building, testing, and deploying serverless applications using the SAM CLI.

• sam build: Packages and prepares your application.
• sam local invoke: Tests individual Lambda functions locally.
• sam local start-api: Simulates API Gateway for local API testing.
• sam deploy: Deploys your application to AWS CloudFormation.

Mastering these commands is key to efficient serverless development!