AWSのLambdaとAPIGatwwayを連携

作りたいもの

要約

なんか簡単な処理をAPIを経由してアクセスしたい
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lambdaでなんかできそう
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postmanで再現するにはホストがいる
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API Gatewayでいけそう⇦今ここ
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多分、APIGateway＋Lambdaの連携でできるかも

lambdaは色々なAWSサービスのトリガーで動作することができる

今回はAPI Gatewayから起動するようにする

やること

1. APIGatewayを作成

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2. APIのリソースを作成

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3. APIのメソッドを作成

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4. lambdaを作成

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添付コード

exports.handler = async (event, context, callback) => {
    
    console.log("EVENT: \n" + JSON.stringify(event, null, 2))
    
    // リクエスト
    console.log("body: ", event.body);
    
    // レスポンス
    const response = {
        statusCode: 200,
        headers: {
            "Content-Type": "application/json"
        },
        body: JSON.stringify({
            "aaa": 111,
            "bbb": "aaa",
        }),
    };
    callback(null, response);
};

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5. APIとLambdaを紐付けデプロイ

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6. curlで確認

 % curl https://5ftyywmhe6.execute-api.ap-northeast-1.amazonaws.com/dev/test1
{"aaa":111,"bbb":"aaa"}%
 %

できた　^_^

おまけ

lambdaからみたAPI Gatewayからのeventの中身

{
    "resource": "/test1",
    "path": "/test1",
    "httpMethod": "GET",
    "headers": {
        "Accept": "*/*",
        "CloudFront-Forwarded-Proto": "https",
        "CloudFront-Is-Desktop-Viewer": "true",
        "CloudFront-Is-Mobile-Viewer": "false",
        "CloudFront-Is-SmartTV-Viewer": "false",
        "CloudFront-Is-Tablet-Viewer": "false",
        "CloudFront-Viewer-Country": "JP",
        "Host": "一応隠す",
        "User-Agent": "curl/7.64.1",
        "Via": "一応隠す",
        "X-Amz-Cf-Id": "一応隠す",
        "X-Amzn-Trace-Id": "一応隠す",
        "X-Forwarded-For": "一応隠す",
        "X-Forwarded-Port": "443",
        "X-Forwarded-Proto": "https"
    },
    "multiValueHeaders": {
        "Accept": [
            "*/*"
        ],
        "CloudFront-Forwarded-Proto": [
            "https"
        ],
        "CloudFront-Is-Desktop-Viewer": [
            "true"
        ],
        "CloudFront-Is-Mobile-Viewer": [
            "false"
        ],
        "CloudFront-Is-SmartTV-Viewer": [
            "false"
        ],
        "CloudFront-Is-Tablet-Viewer": [
            "false"
        ],
        "CloudFront-Viewer-Country": [
            "JP"
        ],
        "Host": [
            "一応隠す"
        ],
        "User-Agent": [
            "curl/7.64.1"
        ],
        "Via": [
            "一応隠す"
        ],
        "X-Amz-Cf-Id": [
            "一応隠す"
        ],
        "X-Amzn-Trace-Id": [
            "一応隠す"
        ],
        "X-Forwarded-For": [
            "一応隠す"
        ],
        "X-Forwarded-Port": [
            "443"
        ],
        "X-Forwarded-Proto": [
            "https"
        ]
    },
    "queryStringParameters": null,
    "multiValueQueryStringParameters": null,
    "pathParameters": null,
    "stageVariables": null,
    "requestContext": {
        "resourceId": "一応隠す",
        "resourcePath": "/test1",
        "httpMethod": "GET",
        "extendedRequestId": "一応隠す",
        "requestTime": "30/Dec/2020:06:47:19 +0000",
        "path": "/dev/test1",
        "accountId": "一応隠す",
        "protocol": "HTTP/1.1",
        "stage": "dev",
        "domainPrefix": "一応隠す",
        "requestTimeEpoch": 一応隠す,
        "requestId": "一応隠す",
        "identity": {
            "cognitoIdentityPoolId": null,
            "accountId": null,
            "cognitoIdentityId": null,
            "caller": null,
            "sourceIp": "一応隠す",
            "principalOrgId": null,
            "accessKey": null,
            "cognitoAuthenticationType": null,
            "cognitoAuthenticationProvider": null,
            "userArn": null,
            "userAgent": "curl/7.64.1",
            "user": null
        },
        "domainName": "一応隠す",
        "apiId": "一応隠す"
    },
    "body": null,
    "isBase64Encoded": false
}

リクエストパラメータ

GETの場合は「queryStringParameters」とかに、POSTの場合は「body」に入るみたい

    "queryStringParameters": null,
    "multiValueQueryStringParameters": null,
    "body": null,

Lambda単体で動作検証したい場合はここにパラメータ突っ込めば良いかな・・・

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