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The First Lambda Example

lamdba-handler

Create Lambda Function via Management Console​

  • https://aws.amazon.com/console/
  • Console Home > Lambda
  • 'Create function'
    • Author from scratch
    • 'Function name' e.g. greeting
    • 'Runtime' > Java 21
    • Press 'Create function'
  • Lambda > Functions > greeting
    • Press 'Upload from' > '.zip or .jar file'
    • Upload: /target/lambda-hello-world-1.0-SNAPSHOT.jar
    • Runtime settings > Edit:
    • Handler: zjc.examples.Greeting::greet > Save
    • Test > Test:
hello-world-01.png

LocalStack Lambda Example​

https://docs.localstack.cloud/user-guide/aws/lambda/
lamdba-handler

Create Docker LocalStack​

version: "3.8"

services:
  localstack:
    container_name: "${LOCALSTACK_DOCKER_NAME:-localstack-main}"
    image: localstack/localstack
    ports:
      - "127.0.0.1:4566:4566"            # LocalStack Gateway
      - "127.0.0.1:4510-4559:4510-4559"  # external services port range
    environment:
      # LocalStack configuration: https://docs.localstack.cloud/references/configuration/
      - DEBUG=${DEBUG:-0}
    volumes:
      - "${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack"
      - "/var/run/docker.sock:/var/run/docker.sock"

Create a Lambda function​

Source Code: https://github.com/ZbCiok/zjc-examples/tree/main/aws/aws/lambda/first-lambda-example​

awslocal lambda create-function \
    --function-name localstack-lambda-example \
    --runtime java21 \
    --zip-file fileb://first-lambda-example-1.0-SNAPSHOT.jar\
    --handler zjc.examples.LambdaMethodHandler::handleRequest \
    --role arn:aws:iam::000000000000:role/lambda-role

Invoke the Function​

awslocal lambda invoke \
    --function-name localstack-lambda-example \
    --cli-binary-format raw-in-base64-out \
    --payload '{ "name": "John Doe", "question": "How are you?" }' output.txt

Output; target/output.txt:​

{"answer":"Subscribe: jreact.com"}