Serverless Backend with AWS Lambda & API Gateway · Aula

Definição de recursos sem servidor

Escreva modelos do SAM para definir funções do Lambda, endpoints do API Gateway, tabelas do DynamoDB e outros componentes sem servidor.

Definição de recursos sem servidor é uma aula grátis de Serverless Backend with AWS Lambda & API Gateway no CoddyKit. Esta é a aula 2 de 4. Você pode ler a aula completa abaixo gratuitamente — depois pratica ao vivo no navegador com um editor de código integrado e um tutor de IA 24/7. Faz parte do caminho de aprendizado de Serverless Backend with AWS Lambda & API Gateway, e seu progresso é sincronizado entre a web e o app CoddyKit. O curso de Serverless Backend with AWS Lambda & API Gateway inclui 4 aulas no total.

Partes desta aula ainda não foram traduzidas e aparecem em inglês.

What are SAM Templates?

AWS Serverless Application Model (SAM) templates are a powerful way to define your serverless applications using Infrastructure as Code (IaC).

Instead of manually configuring resources in the AWS console, you describe them in a YAML or JSON file. This makes your deployments repeatable, version-controlled, and easier to manage.

Anatomy of a SAM Template

A SAM template has a clear structure. The most important parts are:

AWSTemplateFormatVersion: Specifies the template format version.
Transform: Always AWS::Serverless-2016-10-31 for SAM.
Description: A brief description of your application.
Resources: Where you define all your AWS components.

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: My First SAM App

Resources:
  # Your serverless resources go here

Defining a Serverless Function

The core of many serverless applications is the AWS Lambda function. In SAM, you declare a Lambda using the AWS::Serverless::Function resource type.

You need to specify its handler, runtime, and where its code is located.

Resources:
  MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.lambda_handler
      Runtime: python3.9
      CodeUri: s3://my-bucket/my-app.zip
      MemorySize: 128
      Timeout: 30

Key Lambda Properties

Let's break down some common AWS::Serverless::Function properties:

Handler: The entry point in your code (e.g., filename.function_name).
Runtime: The programming language runtime (e.g., python3.9, nodejs18.x).
CodeUri: Path to your function's deployment package (local or S3).
MemorySize: RAM allocated to the function (MB).
Timeout: Max execution time (seconds).

API Gateway as an Event Source

To make your Lambda function accessible via an HTTP endpoint, you integrate it with Amazon API Gateway. In SAM, you do this by adding an Events property to your function.

The HttpApi type is often preferred for its simplicity and cost-effectiveness.

Resources:
  MyApiFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.lambda_handler
      Runtime: python3.9
      CodeUri: s3://my-bucket/api-app.zip
      Events:
        MyApiEvent:
          Type: HttpApi
          Properties:
            Path: /hello
            Method: GET

Defining a DynamoDB Table

For data persistence, you can define a DynamoDB table directly in your SAM template. SAM provides a convenient AWS::Serverless::SimpleTable resource type.

This creates a basic DynamoDB table with a primary key. For more advanced configurations, you can use AWS::DynamoDB::Table.

Resources:
  MyDataTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        Name: id
        Type: String
      ProvisionedThroughput:
        ReadCapacityUnits: 1
        WriteCapacityUnits: 1

IAM Permissions for Resources

Your Lambda functions often need permission to interact with other AWS services, like DynamoDB. You grant these permissions using IAM (Identity and Access Management) policies.

SAM allows you to attach policies directly to your Lambda function's execution role using the Policies property.

Resources:
  MyLambdaWithDbAccess:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.lambda_handler
      Runtime: python3.9
      CodeUri: s3://my-bucket/db-app.zip
      Policies:
        - DynamoDBReadWriteAccess:
            TableName: !Ref MyDataTable # Grants access to MyDataTable
      Events:
        MyApiEvent:
          Type: HttpApi
          Properties:
            Path: /items
            Method: GET
  MyDataTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        Name: id
        Type: String

Exporting Important Values

After deploying your serverless application, you often need to know the endpoint URL of your API or the name of your DynamoDB table.

The Outputs section in your SAM template allows you to export these values, making them easily accessible after deployment.

Outputs:
  ApiUrl:
    Description: "API Gateway endpoint URL for Prod stage for Hello World function"
    Value: !Sub "https://${ServerlessHttpApi}.execute-api.${AWS::Region}.amazonaws.com/hello"

A Full Serverless Template

Here's a more complete SAM template that defines an HTTP API endpoint, a Lambda function to handle requests, and a DynamoDB table for data storage.

Notice how different resource types are declared and linked together.

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A complete serverless API with Lambda and DynamoDB

Resources:
  MyApiFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.lambda_handler
      Runtime: python3.9
      CodeUri: s3://my-bucket/full-app.zip
      Policies:
        - DynamoDBReadWriteAccess:
            TableName: !Ref MyItemsTable
      Events:
        MyApiEvent:
          Type: HttpApi
          Properties:
            Path: /items
            Method: GET

  MyItemsTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        Name: itemId
        Type: String

Outputs:
  ApiEndpoint:
    Description: "API Gateway endpoint URL"
    Value: !Sub "https://${ServerlessHttpApi}.execute-api.${AWS::Region}.amazonaws.com/items"

SAM Template Check

Which of the following are valid top-level sections in a SAM template?

Recap: Defining Serverless Resources

In this lesson, you learned how to define various serverless resources within a SAM template. We covered:

The basic structure of a SAM template.
Declaring AWS::Serverless::Function for Lambda.
Integrating Lambda with API Gateway using Events.
Defining AWS::Serverless::SimpleTable for DynamoDB.
Granting permissions with IAM Policies.
Using the Outputs section to export values.

Next, we'll learn how to deploy these templates to AWS!

Perguntas Frequentes

A aula “Definição de recursos sem servidor” é grátis?

Sim — o texto completo de “Definição de recursos sem servidor” é grátis para ler aqui na web. Para praticá-la interativamente (um editor de código integrado e um tutor de IA 24/7) e desbloquear o restante do curso de Serverless Backend with AWS Lambda & API Gateway, atualize para CoddyKit PRO. O curso de Serverless Backend with AWS Lambda & API Gateway inclui 4 aulas no total.

O que vou aprender em “Definição de recursos sem servidor”?

Escreva modelos do SAM para definir funções do Lambda, endpoints do API Gateway, tabelas do DynamoDB e outros componentes sem servidor. Você pratica Serverless Backend with AWS Lambda & API Gateway com código prático que executa diretamente no navegador, e um tutor de IA 24/7 responde suas dúvidas enquanto trabalha na aula.

Preciso ter experiência prévia para começar Serverless Backend with AWS Lambda & API Gateway?

Nenhuma experiência prévia é necessária. Serverless Backend with AWS Lambda & API Gateway no CoddyKit é estruturado para alunos iniciantes até avançados, então você pode começar aqui ou desde o início e aprender no seu ritmo. Esta é a aula 2 de 4.

Quanto tempo leva a aula “Definição de recursos sem servidor”?

A maioria das aulas CoddyKit leva cerca de 5–10 minutos. Cada uma é compacta e interativa, então você faz progresso constante e retoma exatamente de onde parou entre web e app.

Posso escrever e executar código nesta aula de Serverless Backend with AWS Lambda & API Gateway?

Sim. Cada aula de Serverless Backend with AWS Lambda & API Gateway inclui um editor de código integrado, então você escreve e executa código real direto no navegador e recebe feedback de IA instantaneamente — nenhuma configuração local necessária.

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