kintoneで画像保存にGoogle Driveを使う方法（Cloud Run経由）

import express, { type Request, type Response } from "express";
import cors from "cors";
import multer from "multer";
import { google } from "googleapis";
import { Readable } from "stream";

const PORT = process.env.PORT ? Number(process.env.PORT) : 8080;
const DRIVE_FOLDER_ID = process.env.DRIVE_FOLDER_ID as string;
const ALLOW_ORIGIN = process.env.ALLOW_ORIGIN || "https://<your_kintone_domain>";
const PERMISSION_MODE = (process.env.PERMISSION_MODE || "none") as "none" | "domain" | "anyone";
const PERMISSION_DOMAIN = process.env.PERMISSION_DOMAIN || "";

if (!DRIVE_FOLDER_ID) {
  console.error("DRIVE_FOLDER_ID is required.");
  process.exit(1);
}

const app = express();
app.use(cors({ origin: ALLOW_ORIGIN }));

const upload = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: 50 * 1024 * 1024 } // 50MB
});

const auth = new google.auth.GoogleAuth({
  scopes: ["https://www.googleapis.com/auth/drive"]
});
const drive = google.drive({ version: "v3", auth });

app.post("/upload", upload.array("file"), async (req: Request, res: Response) => {
  try {
    const files = (req.files as Express.Multer.File[]) || [];
    if (!files.length) return res.status(400).json({ error: "no file" });

    const results = [];

    for (const f of files) {
      const meta = {
        name: f.originalname,
        parents: [DRIVE_FOLDER_ID]
      };

      const createRes = await drive.files.create({
        requestBody: meta,
        media: { mimeType: f.mimetype, body: Readable.from(f.buffer) },
        fields: "id,name,webViewLink,webContentLink",
        supportsAllDrives: true
      });

      const fileId = createRes.data.id;

      if (PERMISSION_MODE === "domain" && PERMISSION_DOMAIN) {
        await drive.permissions.create({
          fileId,
          requestBody: { role: "reader", type: "domain", domain: PERMISSION_DOMAIN },
          supportsAllDrives: true
        });
      } else if (PERMISSION_MODE === "anyone") {
        await drive.permissions.create({
          fileId,
          requestBody: { role: "reader", type: "anyone" },
          supportsAllDrives: true
        });
      }

      results.push({
        id: fileId,
        name: createRes.data.name,
        webViewLink: createRes.data.webViewLink,
        webContentLink: createRes.data.webContentLink
      });
    }

    return res.status(200).json(results.length === 1 ? results[0] : results);
  } catch (err: any) {
    console.error(err);
    return res.status(500).json({ error: "upload_failed", detail: err?.message });
  }
});

app.listen(PORT, () => console.log(`listening on :${PORT}`));

// ==== 設定 ====
const API_ENDPOINT = "https://<your-cloud-run-domain>/upload"; // Cloud Run の /upload エンドポイント

// ==== フィールドコード ====
const TABLE = "files"; // サブテーブル
const COL = {
  name: "file_name",       // 文字列(1行)
  id:   "drive_file_id",   // 文字列(1行)
  view: "drive_view_url"   // リンク
};
const SPACE_UPLOAD = "upload_btn"; // スペース（アップロードボタン表示用）

// 空行チェック
function isEmptyRow(row) {
  return !row || !row.value ||
    (!row.value[COL.name]?.value && !row.value[COL.id]?.value);
}

// サブテーブルに1行追加（最初の空行があれば上書き）
function pushRow(record, { id, view, name }) {
  const row = {
    value: {
      [COL.name]: { value: name || "" },
      [COL.id]:   { value: id || "" },
      [COL.view]: { value: view || "" }
    }
  };

  if (record[TABLE].value.length > 0 && isEmptyRow(record[TABLE].value[0])) {
    record[TABLE].value[0] = row;
  } else {
    record[TABLE].value.push(row);
  }
}

// アップロードボタン設置（新規/編集画面）
function setupUploadButton(record) {
  const el = kintone.app.record.getSpaceElement(SPACE_UPLOAD);
  if (!el || el.dataset.inited) return;
  el.dataset.inited = "1";

  const btn = document.createElement("button");
  btn.type = "button";
  btn.textContent = "画像を追加";
  el.appendChild(btn);

  btn.onclick = () => {
    const input = document.createElement("input");
    input.type = "file";
    input.multiple = true;
    input.accept = "image/*";

    input.onchange = async () => {
      const files = Array.from(input.files || []);
      if (!files.length) return;

      for (const f of files) {
        const fd = new FormData();
        fd.append("file", f, f.name);

        const res = await fetch(API_ENDPOINT, { method: "POST", body: fd });
        if (!res.ok) throw new Error("upload failed: " + f.name);

        const body = await res.json(); // { id, webViewLink, webContentLink, ... }

        const data = {
          id: body.id,
          view: body.webViewLink || body.webContentLink || "",
          name: f.name
        };
        pushRow(record, data);
        kintone.app.record.set({ record });
      }

      alert("アップロードが完了しました");
    };

    input.click();
  };
}

(function() {
  kintone.events.on(["app.record.create.show", "app.record.edit.show"], (ev) => {
    setupUploadButton(ev.record);
    return ev;
  });
})();