Optimize images with Firebase Storage and Functions on a fly

firebase-function-image-optimization.js

'use strict';

const functions = require('firebase-functions');
const gcs = require('@google-cloud/storage')();
const spawn = require('child-process-promise').spawn;
const mkdirp = require('mkdirp-promise');
const path = require('path');
const os = require('os');
const fs = require('fs');

exports.optimizeImages = functions.storage.object().onChange(({ data }) => {
    // File and directory paths.
    const filePath = data.name;
    const tempLocalFile = path.join(os.tmpdir(), filePath);
    const tempLocalDir = path.dirname(tempLocalFile);


    // Exit if this is triggered on a file that is not an image.
    if (!data.contentType.startsWith('image/')) {
        console.log('This is not an image.');
        return null;
    }

    // Exit if this is a move or deletion event.
    if (data.resourceState === 'not_exists') {
        console.log('This is a deletion event.');
        return null;
    }

    // Exit if file exists but is not new and is only being triggered
    // because of a metadata change.
    if (data.resourceState === 'exists' && data.metageneration > 1) {
        console.log('This is a metadata change event.');
        return null;
    }

    // Cloud Storage files.
    const bucket = gcs.bucket(data.bucket);
    const file = bucket.file(filePath);

    return file.getMetadata()
        .then(([metadata]) => {
            if (metadata.metadata && metadata.metadata.optimized) {
                return Promise.reject('Image has been already optimized');
            }
            return Promise.resolve();
        })
        .then(() => mkdirp(tempLocalDir))
        .then(() => file.download({ destination: tempLocalFile }))
        .then(() => {
            console.log('The file has been downloaded to', tempLocalFile);
            // Generate a thumbnail using ImageMagick.
            return spawn('convert', [tempLocalFile, '-strip', '-interlace', 'Plane', '-quality', '82', tempLocalFile]);
        })
        .then(() => {
            console.log('Optimized image created at', tempLocalFile);
            // Uploading the Optimized image.
            return bucket.upload(tempLocalFile, {
                destination: file,
                metadata: {
                    metadata: {
                        optimized: true
                    }
                }
            });
        })
        .then(() => {
            console.log('Optimized image uploaded to Storage at', file);
            // Once the image has been uploaded delete the local files to free up disk space.
            fs.unlinkSync(tempLocalFile);

            // Get the Signed URLs for optimized image.
            const config = {
                action: 'read',
                expires: '03-01-2500'
            };
            return file.getSignedUrl(config);
        });
});

I have an error Cannot find module '@google-cloud/storage', but i install the module via npm:
npm install --save @google-cloud/storage

Function load error: Code in file index.js can't be loaded.
Did you list all required modules in the package.json dependencies?
Detailed stack trace: Error: Cannot find module '@google-cloud/storage'
at Function.Module._resolveFilename (module.js:476:15)
at Function.Module._load (module.js:424:25)
at Module.require (module.js:504:17)
at require (internal/module.js:20:19)
at Object. (/user_code/index.js:3:45)
at Module._compile (module.js:577:32)
at Object.Module._extensions..js (module.js:586:10)
at Module.load (module.js:494:32)
at tryModuleLoad (module.js:453:12)
at Function.Module._load (module.js:445:3)

Hello I have an error. const gcs = require('@google-cloud/storage')(); TypeError: require(...) is not a function

Try this
const {Storage} = require('@google-cloud/storage'); const gcs = new Storage();

I have wrote some different function
view here https://gist.github.com/androidovshchik/9e9c8299d393a28f74e17cf09d06d466

• Written in typescript
• Removed deprecated functions. E.g. functions.storage.object().onChange and data.resourceState are not existing now
• Fixes metadata issue. Now when uploading old metadata is not erasing
• Have better optimize arguments fo ImageMagick command
• More safe execution
  And it really works for today