GraphQLを使って指定したGithubリポジトリのプルリクエスト情報を取得・Slackに送信するLambda関数です。

notify-remaining-pullrequests.js

const AWS = require('aws-sdk');
const url = require('url');
const https = require('https');
const GraphQLClient = require('graphql-request').GraphQLClient;

// Github APIで使用するトークン
const token = process.env.token;
// リポジトリの所有者名
const owner = process.env.owner;
// Githubのリポジトリ名
const repo = process.env.repo;
// 送信先のSlackのチャンネル名
const slackChannel = process.env.slackChannel;
// Slackのincoming webhookのURL
const encrypted = process.env['kmsEncryptedHookUrl'];
let decrypted;

// Github API v4のエンドポイント
const endpoint = 'https://api.github.com/graphql';

const client = new GraphQLClient(endpoint, {
  headers: {
    Authorization: 'bearer ' + token,
  },
});

// Github API（GraphQL）のクエリ
const query = `{
  repository(owner: "${owner}", name: "${repo}") {
    pullRequests(last: 10,  states:[OPEN]) {
      edges {
        node {
          number
        }
      }
    }
  }
}`;

// OPEN状態のプルリクエストの情報を取得する
function getOpenedPullRequests(callback) {
  let message;
  client.request(query)
  .then(
    data => {
      // マージされていないプルリクエストの件数を取得
      let number = data.repository.pullRequests.edges.length;
      // 送信するメッセージを定義
      message = 'マージされていないプルリクエストが' + number + '件あります。';

      postMessage(message, (response) => {
      if (response.statusCode < 400) {
          console.info('Message posted successfully');
          callback(null);
      } else if (response.statusCode < 500) {
          console.error(`Error posting message to Slack API: ${response.statusCode} - ${response.statusMessage}`);
          callback(null);  // Don't retry because the error is due to a problem with the request
      } else {
          // Let Lambda retry
          callback(`Server error when processing message: ${response.statusCode} - ${response.statusMessage}`);
      }
    });
  }
).catch(err => {
  console.log(err.response.errors); // GraphQL response errors
  console.log(err.response.data); // Response data if available
  });
}

// Slackにメッセージを送信する
function postMessage(message, callback) {
  const slackMessage = {
    channel: slackChannel,
    text: message.toString()
  };
  console.log(slackMessage);
  const body = JSON.stringify(slackMessage);
  const options = url.parse(decrypted);
  options.method = 'POST';
  options.headers = {
    'Content-Type': 'application/json',
    'Content-Length': Buffer.byteLength(body),
  };

  const postReq = https.request(options, (res) => {
    const chunks = [];
    res.setEncoding('utf8');
    res.on('data', (chunk) => chunks.push(chunk));
    res.on('end', () => {
      if (callback) {
        callback({
          body: chunks.join(''),
          statusCode: res.statusCode,
          statusMessage: res.statusMessage,
        });
      }
    });
    return res;
  });

  postReq.write(body);
  postReq.end();
}

function processEvent(event, context, callback) {
  getOpenedPullRequests(callback);
}

exports.handler = (event, context, callback) => {
  if (decrypted) {
    processEvent(event, context, callback);
  } else {
    // Decrypt code should run once and variables stored outside of the function
    // handler so that these are decrypted once per container
    const kms = new AWS.KMS();
    kms.decrypt({ CiphertextBlob: new Buffer(encrypted, 'base64') }, (err, data) => {
        if (err) {
            console.log('Decrypt error:', err);
            return callback(err);
        }
        decrypted = data.Plaintext.toString('ascii');
        processEvent(event, context, callback);
    });
  }
};