如何使用 firebase admin sdk 获取 downloadUrl firebase 存储并使用 multer 在 nodejs 中放入 img html 的标签？

Question

我正在构建图片上传系统。我想使用 Firebase Admin sdk 来处理这个过程。如何让 url 存储在我的 Google 云存储中，并在上传完成后在 img 标签 (html) 中显示它们。

try {
    const file = req.file;
    const bucket = admin.storage().bucket();
    const imageBuffer = Buffer.from(file.buffer, "base64");
    const imageByteArray = new Uint8Array(imageBuffer);
    const options = {
      resumable: false,
      metadata: { contentType: file.mimetype },
      predefinedAcl: "publicRead",
      public: true,
    };
    const files = bucket.file(`img/${file.originalname}`);
    await files.save(imageByteArray, options);
    const field = await files.getMetadata();
    console.log(field);
  } catch (e) {
    console.error(e);
  }

Answer 1

使用 Node.js Admin SDK，您应该使用 getSignedUrl() 方法执行以下操作：

const { initializeApp, cert } = require('firebase-admin/app');
const { getStorage } = require('firebase-admin/storage');

const serviceAccount = require('./path/to/serviceAccountKey.json');

initializeApp({
  credential: cert(serviceAccount),
  storageBucket: '<BUCKET_NAME>.appspot.com'
});


// ...

async function getSignedURL(fileName) {
    const bucket = getStorage().bucket();
    // Or const bucket = admin.storage().bucket(); like you do in your question, depending on where and how you execute the code
    const file = bucket.file(fileName);

    const signedURLconfig = { action: 'read', expires: '01-01-2030' };
    // See more options of the config object in the SDK documentation (link above)

    const signedURLArray = await file.getSignedUrl(signedURLconfig);
    return signedURLArray[0];
}


// Use the above function to save the signed URL to Firestore
const fileName = "...";
getSignedURL(fileName)
.then(signedURL => {
    admin.firestore().collection("urls_collection")
    .add({url: signedURL, foo: "bar", bar: "foo"})
});