Scala

g8 で雛形をつくり

$ sbt new scala/scala-seed.g8
WARN: No sbt.version set in project/build.properties, base directory: /Users/hoge/Projects/aws-lambda-in-scala
[warn] Executing in batch mode.
[warn]   For better performance, hit [ENTER] to switch to interactive mode, or
[warn]   consider launching sbt without any commands, or explicitly passing 'shell'
[info] Set current project to aws-lambda (in build file:/Users/hoge/Projects/aws-lambda-in-scala/)

A minimal Scala project.

name [Scala Seed Project]: AWS lambda in Scala

Template applied in ./aws-lambda-in-scala

適当にコードを書く

package example

import scala.collection.JavaConverters._
import com.amazonaws.services.lambda.runtime.Context

object Lambda {

  def handler(lambdaInput: Int, context: Context): java.util.List[String] = {
    val logger = context.getLogger
    logger.log("start lambda handler")
    execute(lambdaInput)
  }

  def execute(input: Int): java.util.List[String] = {
    List("%d".format(input)).asJava
  }

}

AWS

事前準備

lambda_exec_role という IAM ロールを事前に作成。 AWSLambdaFullAccess と CloudWatchLogsFullAccess のポリシーをアタッチ。

Lambda Function を登録

#!/usr/bin/env bash

export AWS_DEFAULT_PROFILE=lambdatest
AWS_ACCOUNT_ID=xxxxxxxxxxxxxx
aws lambda create-function \
 --region ap-northeast-1 \
 --function-name aws-lambda-in-scala \
 --zip-file fileb://target/scala-2.12/aws-lambda-in-scala-assembly-0.1.0-SNAPSHOT.jar \
 --role arn:aws:iam::${AWS_ACCOUNT_ID}:role/lambda_exec_role \
 --handler example.Lambda::handler \
 --runtime java8 \
 --timeout 15 \
 --memory-size 512

実行

#!/usr/bin/env bash

export AWS_DEFAULT_PROFILE=lambdatest
aws lambda invoke \
 --region ap-northeast-1 \
 --function-name aws-lambda-in-scala \
 --payload 123 \
 --invocation-type RequestResponse /tmp/lambdatest.log

確認

$ cat /tmp/lambdatest.log 
["123"]

CloudWatchLogs にもログが出力されてた。