eusthace811 · April 17, 2019 13:52 · Jun 28, 2017
diff --git a/index.js b/index.js
@@ -0,0 +1,59 @@
+const functions = require('firebase-functions');
+const gcs = require('@google-cloud/storage')();
+const sharp = require('sharp')
+const _ = require('lodash');
+const path = require('path');
+const os = require('os');
+
+exports.generateThumbnail = functions.storage.object('uploads/{imageId}').onChange(event => {
+
+  const object = event.data; // The Storage object.
+
+  console.log(object)
+
+  const fileBucket = object.bucket; // The Storage bucket that contains the file.
+  const filePath = object.name; // File path in the bucket.
+  const contentType = object.contentType; // File content type.
+  const resourceState = object.resourceState; // The resourceState is 'exists' or 'not_exists' (for file/folder deletions).
+  const metageneration = object.metageneration; // Number of times metadata has been generated. New objects have a value of 1.
+
+  const SIZES = [64, 256, 512]; // Resize target width in pixels
+
+  if (!contentType.startsWith('image/') || resourceState == 'not_exists') {
+    console.log('This is not an image.');
+    return;
+  }
+
+  if (_.includes(filePath, '_thumb')) {
+    console.log('already processed image');
+    return;
+  }
+
+
+  const fileName = filePath.split('/').pop();
+  const bucket = gcs.bucket(fileBucket);
+  const tempFilePath = path.join(os.tmpdir(), fileName);
+
+  return bucket.file(filePath).download({
+    destination: tempFilePath
+  }).then(() => {
+
+    _.each(SIZES, (size) => {
+
+      let newFileName = `${fileName}_${size}_thumb.png`
+      let newFileTemp = path.join(os.tmpdir(), newFileName);
+      let newFilePath = `thumbs/${newFileName}`
+
+      sharp(tempFilePath)
+        .resize(size, null)
+        .toFile(newFileTemp, (err, info) => {
+
+          bucket.upload(newFileTemp, {
+            destination: newFilePath
+          });
+
+        });
+
+    })
+  })
+})
diff --git a/package.json b/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "functions",
+  "description": "Cloud Functions for Firebase",
+  "dependencies": {
+    "@google-cloud/storage": "^0.4.0",
+    "firebase-admin": "^4.1.2",
+    "firebase-functions": "^0.5",
+    "lodash": "^4.17.4",
+    "request-promise": "^2.0.0",
+    "sharp": "^0.18.1"
+  },
+  "private": true
+}