LocalStackを用いて、DynamoDBにデータ登録を行うAPIをAPI Gateway + Lambdaで作成する方法についてメモする。

LocalStack 準備

こちらの手順でDocker LocalStack環境を準備しておく。

Dynamo DB 準備

テーブル(sample-table)作成

aws dynamodb create-table --table-name sample-table --attribute-definitions AttributeName=Data,AttributeType=S --key-schema AttributeName=Data,KeyType=HASH --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1 --endpoint-url=http://localhost:4569 --profile localstack

{
    "TableDescription": {
        "AttributeDefinitions": [
            {
                "AttributeName": "Data",
                "AttributeType": "S"
            }
        ],
        "TableName": "sample-table",
        "KeySchema": [
            {
                "AttributeName": "Data",
                "KeyType": "HASH"
            }
        ],
        "TableStatus": "ACTIVE",
        "CreationDateTime": "2021-10-09T14:55:59.763000+09:00",
        "ProvisionedThroughput": {
            "LastIncreaseDateTime": "1970-01-01T09:00:00+09:00",
            "LastDecreaseDateTime": "1970-01-01T09:00:00+09:00",
            "NumberOfDecreasesToday": 0,
            "ReadCapacityUnits": 1,
            "WriteCapacityUnits": 1
        },
        "TableSizeBytes": 0,
        "ItemCount": 0,
        "TableArn": "arn:aws:dynamodb:ddblocal:000000000000:table/sample-table"
    }
}

動作確認(データ登録)

aws dynamodb put-item --table-name sample-table --item={\"Data\":{\"S\":\"fuga\"}}  --endpoint-url=http://localhost:4569 --profile localstack

登録データ確認

aws dynamodb scan --table-name sample-table --endpoint-url=http://localhost:4569 --profile localstack
{
    "Items": [
        {
            "Data": {
                "S": "fuga"
            }
        }
    ],
    "Count": 1,
    "ScannedCount": 1,
    "ConsumedCapacity": null
}

API Gateway 準備

REST API を作成する

リソースID(id)を控える

aws apigateway create-rest-api --name 'LambdaDynamoDBTestAPI' --endpoint-url=http://localhost:4567 --region us-east-1 --profile localstack
{
    "id": "0157166521",
    "name": "'LambdaDynamoDBTestAPI'",
    "createdDate": "2021-10-09T06:01:05.462000+00:00"
}

ルートリソースID(以下id)取得

aws apigateway get-resources --rest-api-id 0157166521 --endpoint-url=http://localhost:4567 --region us-east-1 --profile localstack
{
    "items": [
        {
            "id": "4739445932",
            "path": "/",
            "resourceMethods": {
                "GET": {}
            }
        }
    ]
}

子リソース追加

パス名：lambda_dynamodb_test

リソースID(以下id)を控える。

aws apigateway create-resource --rest-api-id 0157166521 --parent-id 4739445932 --path-part lambda_dynamodb_test --endpoint-url=http://localhost:4567 --region us-east-1 --profile localstack
{
    "id": "A-Z13318A-Z712",
    "parentId": "4739445932",
    "pathPart": "lambda_dynamodb_test",
    "path": "/lambda_dynamodb_test",
    "resourceMethods": {
        "GET": {}
    }
}

HTTP POSTメソッド追加

aws apigateway put-method --rest-api-id 0157166521 --resource-id A-Z13318A-Z712 --http-method POST --authorization-type "NONE" --endpoint-url=http://localhost:4567 --region us-east-1 --profile localstack
{
    "httpMethod": "POST",
    "authorizationType": "NONE"
}

Lambda 準備

lambda_dynamodb_put_test.py

DynamoDBテーブルsample-tableにデータを登録する。

import boto3
from boto3.session import Session
from datetime import datetime 

session = Session(aws_access_key_id='dummy',
    aws_secret_access_key='dummy',
    region_name='ap-northeast-1'
)

dynamodb = session.resource(
    service_name='dynamodb', 
    endpoint_url='http://localhost:4569'
)

def lambda_handler(event, context):
    table = dynamodb.Table('sample-table')
    data = 'sample_' + datetime.now().strftime('%Y-%m-%d-%H-%M-%S')
    response = table.put_item(
       Item={
            'Data': data
        }
    )
    return response

上記ファイルをlambda_dynamodb_put_test.zipにzip化する。

アップロード

aws lambda create-function --function-name="lambda-dynamodb-put" --runtime=python3.8 --role="arn:aws:iam::123456789012:role/service-role/lambda-sample-role" --handler=lambda_dynamodb_put_test.lambda_handler --zip-file fileb://lambda_dynamodb_put_test.zip --endpoint-url=http://localhost:4574 --profile=localstack

起動

aws lambda invoke --cli-binary-format raw-in-base64-out --function-name lambda-dynamodb-put result.log --endpoint-url=http://localhost:4574 --profile=localstack

{"StatusCode": 200}


* 動作確認

```shell
aws dynamodb scan --table-name sample-table --endpoint-url=http://localhost:4569 --profile localstack

{
  "Items": [
      {
          "Data": {
              "S": "fuga"
          }
      },
      {
          "Data": {
              "S": "sample_2021-10-09-06-38-16"
          }
      }
  ],
  "Count": 2,
  "ScannedCount": 2,
  "ConsumedCapacity": null
}

※データが追加されている。

API Gateway - Lambda 設定

Lambda ARN確認

aws lambda list-functions --endpoint-url=http://localhost:4574 --profile=localstack{    "Functions": [        {            "FunctionName": "lambda-dynamodb-put",            "FunctionArn": "arn:aws:lambda:us-east-1:000000000000:function:lambda-dynamodb-put",            "Runtime": "python3.8",            "Handler": "lambda_dynamodb_put_test.lambda_handler",            "Timeout": 60,            "Version": "$LATEST"        }    ]}

API Gateway - Lambda設定

aws apigateway put-integration --rest-api-id 0157166521 --resource-id A-Z13318A-Z712 --http-method POST --type AWS_PROXY --integration-http-method POST --uri arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:000000000000:function:lambda-dynamodb-put/invocations --passthrough-behavior WHEN_NO_MATCH --endpoint-url=http://localhost:4567 --region us-east-1 --profile localstack {    "type": "AWS_PROXY",    "httpMethod": "POST",    "uri": "arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:000000000000:function:lambda-dynamodb-put/invocations",    "integrationResponses": {        "200": {            "statusCode": 200,            "responseTemplates": {                "application/json": null            }        }    }}

設定デプロイ

aws apigateway create-deployment --rest-api-id 0157166521 --stage-name test --endpoint-url=http://localhost:4567 --region us-east-1 --profile localstack{    "id": "1850348379",    "description": "",    "createdDate": "2021-10-09T06:43:04.032000+00:00"}

動作確認

APIリクエスト

POST /restapis/0157166521/test/_user_request_/lambda_dynamodb_test HTTP/1.1
Host: localhost:4567
Content-Type: application/json
Content-Length: 2

{}

APIレスポンス

{"ResponseMetadata": {"RetryAttempts": 0, "HTTPStatusCode": 200, "RequestId": "9f2c5ca3-6187-4d92-811d-5cd62c5f5289", "HTTPHeaders": {"x-amzn-requestid": "9f2c5ca3-6187-4d92-811d-5cd62c5f5289", "content-length": "2", "access-control-allow-methods": "HEAD,GET,PUT,POST,DELETE,OPTIONS,PATCH", "server": "BaseHTTP/0.3 Python/2.7.13, Jetty(8.1.12.v20130726)", "x-amz-crc32": "2745614147", "date": "Sat, 09 Oct 2021 06:44:22 GMT", "access-control-allow-origin": "*", "access-control-allow-headers": "authorization,content-type,content-md5,x-amz-content-sha256,x-amz-date,x-amz-security-token,x-amz-user-agent", "content-type": "application/x-amz-json-1.0"}}}

DynamoDB登録データ確認

aws dynamodb scan --table-name sample-table --endpoint-url=http://localhost:4569 --profile localstack

{
    "Items": [
        {
            "Data": {
                "S": "fuga"
            }
        },
        {
            "Data": {
                "S": "sample_2021-10-09-06-38-16"
            }
        },
        {
            "Data": {
                "S": "sample_2021-10-09-06-44-22"
            }
        }
    ],
    "Count": 3,
    "ScannedCount": 3,
    "ConsumedCapacity": null
}

※データが追加されている。

参考情報