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September 7, 2024

Lambda Function Running Spring Boot in Docker Image

kotlin

lambda

springboot

Contents

Repository

Serverless Framework

serverless.yml
service: billie-payment-kotlin-dockerized

provider:
  name: aws
  region: ap-southeast-2
  stage: uat
  architecture: arm64 # because I am using macbook air m2, otherwise empty this field
  iam:
    role:
      name: ${self:service}-${self:provider.stage}-role
  ecr:
    images:
      billie-payment-kotlin-lambda-uat:
        path: ./

functions:
  api:
    image:
      name: billie-payment-kotlin-lambda-uat
    timeout: 900
    environment:
      SPRING_PROFILES_ACTIVE: uat
    events:
      - http: ANY /
      - http: ANY /{proxy+}

custom:
  serverless-offline:
    useDocker: true

plugins:
  - serverless-offline
Dockerfile

Make sure to use your correct .jar filename:

FROM gradle:8.10.0-jdk21-alpine AS build
WORKDIR /app
COPY . .
RUN gradle bootJar --no-daemon

FROM public.ecr.aws/lambda/java:21
RUN mkdir -p $LAMBDA_TASK_ROOT/lib/
ARG JAR_FILE="application.jar"
COPY --from=build /app/build/libs/${JAR_FILE} $LAMBDA_TASK_ROOT
RUN mkdir -p ${LAMBDA_TASK_ROOT}/extract && \
    cd ${LAMBDA_TASK_ROOT}/extract && \
    jar -xf ${LAMBDA_TASK_ROOT}/${JAR_FILE} && \
    mv ${LAMBDA_TASK_ROOT}/extract/BOOT-INF/classes/* ${LAMBDA_TASK_ROOT}/ && \
    mv ${LAMBDA_TASK_ROOT}/extract/BOOT-INF/lib/* ${LAMBDA_TASK_ROOT}/lib && \
    mv ${LAMBDA_TASK_ROOT}/extract/META-INF/* ${LAMBDA_TASK_ROOT}/META-INF/ && \
    if [ -d ${LAMBDA_TASK_ROOT}/BOOT-INF/classes/META-INF ]; then \
        mv ${LAMBDA_TASK_ROOT}/BOOT-INF/classes/META-INF/* ${LAMBDA_TASK_ROOT}/META-INF/ && \
        rmdir ${LAMBDA_TASK_ROOT}/BOOT-INF/classes/META-INF; \
    fi && \
    rm -rf ${LAMBDA_TASK_ROOT}/extract ${LAMBDA_TASK_ROOT}/${JAR_FILE} ${LAMBDA_TASK_ROOT}/BOOT-INF

CMD ["com.billie.payment.StreamLambdaHandler::handleRequest"]

PostgreSQL Specific Integration

For detail please refer to this article. Which includes

  • Enum Handling (special annotatoin needed)
  • Tables are named in camel cases (special PhysicalNamingStrategy needed)

Spring Boot Specialized for Lambda

Write the following file at the same level as the entrypoint of the application:

Dependencies
implementation("com.amazonaws:aws-lambda-java-core:1.2.3")
implementation("com.amazonaws.serverless:aws-serverless-java-container-springboot3:2.0.3")
Initializr

StreamLambdaHandler.handleRequest
package com.billie.payment

import com.amazonaws.serverless.exceptions.ContainerInitializationException
import com.amazonaws.serverless.proxy.model.AwsProxyRequest
import com.amazonaws.serverless.proxy.model.AwsProxyResponse
import com.amazonaws.serverless.proxy.spring.SpringBootLambdaContainerHandler
import com.amazonaws.services.lambda.runtime.Context
import com.amazonaws.services.lambda.runtime.RequestStreamHandler
import java.io.IOException
import java.io.InputStream
import java.io.OutputStream


class StreamLambdaHandler : RequestStreamHandler {
    @Throws(IOException::class)
    override fun handleRequest(inputStream: InputStream, outputStream: OutputStream, context: Context) {
        handler!!.proxyStream(inputStream, outputStream, context)
    }

    companion object {
        private var handler: SpringBootLambdaContainerHandler<AwsProxyRequest, AwsProxyResponse>? = null

        init {
            try {
                handler = SpringBootLambdaContainerHandler.getAwsProxyHandler(PaymentApplication::class.java)
            } catch (e: ContainerInitializationException) {
                e.printStackTrace()
                throw RuntimeException("Could not initialize Spring Boot application", e)
            }
        }
    }
}