AWS Lambda入門②(Node編)〜DynamoDBにアクセスする〜

service:sls-sample# AWS周りの設定provider:name:awsruntime:nodejs12.xregion:ap-northeast-1stage:devenvironment:DYNAMODB_TABLE:${self:service}-${self:provider.stage}iamRoleStatements:-Effect:AllowAction:-dynamodb:Query-dynamodb:Scan-dynamodb:GetItem-dynamodb:PutItem-dynamodb:UpdateItem-dynamodb:DeleteItemResource:'arn:aws:dynamodb:${self:provider.region}:*:table/${self:provider.environment.DYNAMODB_TABLE}*'# Lambdaの設定functions:hello:handler:handler.hello# DynamoDBの設定resources:Resources:Hello:Type:AWS::DynamoDB::TableProperties:TableName:${self:provider.environment.DYNAMODB_TABLE}-helloAttributeDefinitions:-AttributeName:idAttributeType:SKeySchema:-AttributeName:idKeyType:HASHProvisionedThroughput:ReadCapacityUnits:1WriteCapacityUnits:1

environment:DYNAMODB_TABLE:${self:service}-${self:provider.stage}iamRoleStatements:-Effect:AllowAction:-dynamodb:Query-dynamodb:Scan-dynamodb:GetItem-dynamodb:PutItem-dynamodb:UpdateItem-dynamodb:DeleteItemResource:'arn:aws:dynamodb:${self:provider.region}:*:table/${self:provider.environment.DYNAMODB_TABLE}*'

resources:Resources:Hello:Type:AWS::DynamoDB::TableProperties:TableName:${self:provider.environment.DYNAMODB_TABLE}-helloAttributeDefinitions:-AttributeName:idAttributeType:SKeySchema:-AttributeName:idKeyType:HASHProvisionedThroughput:ReadCapacityUnits:1WriteCapacityUnits:1

sls deploy

npm i aws-sdk
# or
yarn add aws-sdk

'use strict';// AWS SDKをimportconstAWS=require('aws-sdk');// DynamoDBにアクセスするためのクライアントの初期化constdynamo=newAWS.DynamoDB.DocumentClient();// 環境変数からテーブル名を取得(あとでserverless.ymlに設定します)consttableName=process.env.tableName;// 全量取得module.exports.getAll=async()=>{constparams={TableName:tableName,};try{// DynamoDBにscanでアクセスconstresult=awaitdynamo.scan(params).promise();// 正常に取得できたらその値を返すreturn{statusCode:200,body:JSON.stringify(result.Items),};}catch(error){// エラーが発生したらエラー情報を返すreturn{statusCode:error.statusCode,body:error.message,};}};module.exports.hello=asyncevent=>{return{statusCode:200,body:JSON.stringify({message:event}),};};

# ...省略functions:hello:handler:handler.hellogetAll:handler:handler.getAllenvironment:tableName:${self:provider.environment.DYNAMODB_TABLE}-hello# ...省略

yarn add -D serverless-dynamodb-local

# ...省略plugins:-serverless-dynamodb-localcustom:dynamodb:stages:devstart:port:8082inMemory:truemigrate:trueseed:trueseed:hello:sources:-table:${self:provider.environment.DYNAMODB_TABLE}-hellosources:[./seeds/hello.json]

[{"id":"1","message":"Hello"},{"id":"2","message":"Hello！!!"},{"id":"3","message":"Hello World"}]

sls install dynamodb

'use strict';constAWS=require('aws-sdk');// 環境変数にLOCALが設定されていたらローカルDB用の設定を使う(portはymlで定義したものを設定)constoptions=process.env.LOCAL?{region:'localhost',endpoint:'http://localhost:8082'}:{};constdynamo=newAWS.DynamoDB.DocumentClient(options);// ...省略

sls dynamodb start

$ sls dynamodb start
Dynamodb Local Started, Visit: http://localhost:8082/shell
Serverless: DynamoDB - created table sls-sample-dev-hello
Seed running complete for table: sls-sample-dev-hello

LOCAL=true sls invoke local--function getAll

{"statusCode":200,"body":"[{\"message\":\"Hello\",\"id\":\"1\"},{\"message\":\"Hello！\",\"id\":\"2\"},{\"message\":\"Hello World\",\"id\":\"3\"}]"}

sls deploy

sls invoke --function getAll

{"statusCode":200,"body":"[]"}

// ...省略// 1件取得module.exports.get=asyncevent=>{// パラメータで渡されたidを取得const{id}=event;// 検索条件のidを指定constparams={TableName:tableName,Key:{id},};try{constresult=awaitdynamo.get(params).promise();return{statusCode:200,body:JSON.stringify(result.Item),};}catch(error){return{statusCode:error.statusCode,body:error.message,};}};// 1件登録module.exports.put=asyncevent=>{// 一意な値を作るためにタイムスタンプを取得constid=String(Date.now());const{message}=event;constparams={TableName:tableName,Item:{id,message},};try{constresult=awaitdynamo.put(params).promise();return{statusCode:200,body:JSON.stringify(result),};}catch(error){return{statusCode:error.statusCode,body:error.message,};}};

# ...省略functions:hello:handler:handler.hellogetAll:handler:handler.getAllenvironment:tableName:${self:provider.environment.DYNAMODB_TABLE}-helloget:handler:handler.getenvironment:tableName:${self:provider.environment.DYNAMODB_TABLE}-helloput:handler:handler.putenvironment:tableName:${self:provider.environment.DYNAMODB_TABLE}-hello

LOCAL=true sls invoke local--function put --data'{"message": "Hello!!!!!"}'

{"statusCode":200,"body":"{\"id\":\"1583340674414\",\"message\":\"Hello!!!!!\"}"}

LOCAL=true sls invoke local--function get --data'{"id": "1"}'

{"statusCode":200,"body":"{\"message\":\"Hello\",\"id\":\"1\"}"}

sls deploy

sls invoke --function put --data'{"message": "Hello!!!!!"}'

{"statusCode":200,"body":"{\"id\":\"1583340839287\",\"message\":\"Hello!!!!!\"}"}

sls invoke --function get --data'{"id": "1583340839287"}'

{"statusCode":200,"body":"{\"id\":\"1583340839287\",\"message\":\"Hello!!!!!\"}"}

module.exports.query=asyncevent=>{const{id}=event;constparams={TableName:tableName,KeyConditionExpression:'id = :id',ExpressionAttributeValues:{':id':id},};try{constresult=awaitdynamo.query(params).promise();return{statusCode:200,body:JSON.stringify(result.Items),};}catch(error){return{statusCode:error.statusCode,body:error.message,};}};