[Zendesk+Slack] Slack スラッシュコマンドから Zendesk チケットを起票する仕組みを構築する [2/3]

const https = require("https");

const ZENDESK_DOMAIN = process.env.ZENDESK_DOMAIN;
const ZENDESK_EMAIL = process.env.ZENDESK_EMAIL;
const ZENDESK_API_TOKEN = process.env.ZENDESK_API_TOKEN;
const SAFE_MODE = process.env.SAFE_MODE === "true";

exports.handler = async (event) => {
  for (const record of event.Records) {
    const body = JSON.parse(record.body);

    const subject = body.subject || "Slack からの問い合わせ";
    const message = body.message || "";

    if (SAFE_MODE) {
      console.log("🛡️ SAFE_MODE 有効化中のため、Zendesk API 呼び出しをスキップします。");
      console.log("SKIP subject:", subject);
      console.log("SKIP message:", message);
      continue;
    }

    const postData = JSON.stringify({
      ticket: {
        subject,
        comment: { body: message }
      }
    });

    const auth = Buffer.from(`${ZENDESK_EMAIL}:${ZENDESK_API_TOKEN}`).toString("base64");

    const options = {
      hostname: ZENDESK_DOMAIN,
      path: "/api/v2/tickets.json",
      method: "POST",
      headers: {
        "Authorization": `Basic ${auth}`,
        "Content-Type": "application/json",
        "Content-Length": Buffer.byteLength(postData)
      }
    };

    await new Promise((resolve, reject) => {
      const req = https.request(options, (res) => {
        let data = "";
        res.on("data", chunk => data += chunk);
        res.on("end", () => {
          if (res.statusCode === 201) {
            console.log("✅ チケット作成成功");
            resolve();
          } else {
            console.error("❌ Zendesk エラー:", res.statusCode, data);
            reject(new Error(`Zendesk returned ${res.statusCode}`));
          }
        });
      });

      req.on("error", (e) => {
        console.error("❌ リクエストエラー:", e);
        reject(e);
      });

      req.write(postData);
      req.end();
    });
  }
};

{
  "Records": [
    {
      "body": "{\"subject\": \"テスト件名\", \"message\": \"これはテストメッセージです。\"}"
    }
  ]
}

mkdir slack-zendesk-request-handler
cd slack-zendesk-request-handler
npm init -y
npm install aws-sdk

const crypto = require("crypto");
const querystring = require("querystring");
const { SQS } = require("aws-sdk");

const sqs = new SQS();
const QUEUE_URL = process.env.QUEUE_URL;
const SIGNING_SECRET = process.env.SLACK_SIGNING_SECRET;

exports.handler = async (event) => {
  const headers = Object.fromEntries(
    Object.entries(event.headers || {}).map(([k, v]) => [k.toLowerCase(), v])
  );

  const timestamp = headers["x-slack-request-timestamp"];
  const signature = headers["x-slack-signature"];
  if (!timestamp || !signature) {
    return { statusCode: 400, body: "Missing headers" };
  }

  // Replay attack 対策
  const now = Math.floor(Date.now() / 1000);
  if (Math.abs(now - timestamp) > 60 * 5) {
    return { statusCode: 403, body: "Request too old" };
  }

  const rawBody = event.isBase64Encoded
    ? Buffer.from(event.body, "base64").toString("utf8")
    : event.body;

  const sigBaseString = `v0:${timestamp}:${rawBody}`;
  const expectedSig = "v0=" + crypto
    .createHmac("sha256", SIGNING_SECRET)
    .update(sigBaseString, "utf8")
    .digest("hex");

  // 署名検証
  if (
    !crypto.timingSafeEqual(
      Buffer.from(signature, "utf8"),
      Buffer.from(expectedSig, "utf8")
    )
  ) {
    return { statusCode: 403, body: "Invalid signature" };
  }

  const body = querystring.parse(rawBody);
  const user = body.user_name || "unknown";
  const text = body.text || "";

  const message = {
    subject: `Slack ユーザー ${user} からの問い合わせ`,
    message: text
  };

  await sqs.sendMessage({
    QueueUrl: QUEUE_URL,
    MessageBody: JSON.stringify(message)
  }).promise();

  return {
    statusCode: 200,
    body: "受け付けました"
  };
};

zip -r function.zip .

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "sqs:SendMessage",
      "Resource": "arn:aws:sqs:********"
    }
  ]
}

{
  "headers": {
    "X-Slack-Request-Timestamp": "1234567890",
    "X-Slack-Signature": "v0=fake"
  },
  "body": "user_name=testuser&text=問い合わせ内容です"
}