Dall-e API on Firebase

Just getting the story started here on generating Dall-e images from Firebase. After plugging the API into a node.js function, I realized that the images expire after an hour, so if I want to let our players view their image generation history, I’m going to need to set up an image processing pipeline using a a Firebase function or two.

Cats with brains on outside of their heads

So, here’s the plan:

1. Node express API (running as Firebase function) which generates a Dalle image on request and returns the Url.
2. Store the Image Url in firebase for that player

Few days later: Massive detour on the way to the above. Turns out the Dalle images expire after an hour, so needed a server side method to get the image from Dalle and bring it over to Firebase Storage.

Here’s the function that generates the image from Dalle — and then the function that takes the Dalle URL (or any URL), stores it in Firebase Storage (Gcp) and then generates a public URL for it.

import { v4 as uuidv4 } from 'uuid';
import path from 'path';
import got from 'got';
import { Storage } from '@google-cloud/storage';

const storage = new Storage({
  projectId: 'FIREBASEPROJECTID',
  keyFilename: 'PATHTO_SERVICE_ACCTJSON'
});
const storageBucket = config.production.firebaseConfig.storageBucket;

//--------OPENAI-------------
import { Configuration, OpenAIApi } from "openai"; 
const openai_configuration = new Configuration({
  apiKey: 'APIKEY',
});
const openai = new OpenAIApi(openai_configuration);

//----------------------THUMBS----------------------
/**
 * GET THUMBS
 * Gets thumbnails from Dalle, given a phrase
 *
 * @param {string} phrase user typed phrase
 * @return {array} N thumbnail url that matching phrase
 */
 dalleRouter.get("/thumbs", async (req, res, next) => {
  console.log('->dalle thumbs, phrase is:', req.query.phrase)
  const ret = await openai.createImage({
    prompt: req.query.phrase,
    n: 1,
    size: "256x256",
  });
  let image_urls = ret.data.data;
  console.log(image_urls)
  res.status(200).json({'result':'success','data':image_urls})
});

//----------------------TRANSMOGRIFY----------------------
/**
 * TRANSMOGRIFY
 * Takes a Dalle URL and saves it to firebase storage, then returns the signed URL
 * https://stackoverflow.com/questions/37686213/upload-image-from-url-to-firebase-storage
 * @param {string} url url of dalle image
 * @return {string} signed url of same image saved to server
 */
dalleRouter.get("/transmogrify", async (req, res) => {
  let source_url = req.query.url;
  console.log('->dalle transmogrify, url is:', source_url);
  
  //create a new filename for this image
  let uuid = uuidv4();
  let fileName = `images/${uuid}.png`; 

  //get a reference to where we want to put this file in the bucket
  const file = storage
    .bucket(storageBucket)
    .file(fileName);

  //get the byte stream from teh source url and pipe it to the new location in bucket
   got.stream(source_url)
    .pipe(file.createWriteStream({
      metadata: {
        contentType: 'image/png'
      }
    }))
    .on('error', (err) => {
      console.error(err);
      res.status(500).json({'result':'error','msg':err})
    })
    .on('finish', () => {
      console.log(`Finished copying ${source_url} to ${fileName} `);
      //now get a signed URL with expiry date far in the future 
        file.getSignedUrl({
          action: 'read',
          expires: '03-09-2491'
        }).then(signedUrls => {
          //console.log('URL',signedUrls[0]);
          //return the signed URL to player
          res.status(200).json({'result':'success','signed_url':signedUrls[0]})
        });
  });