Google Drive Source

Write articles, store images, whatever in Google Drive and then download them to a specified folders.

I built this to keep my Gatsby blog up to date by writing Markdown and saving images in Google Drive and then syncing that to my blog. Turns out, it also supports Google Drawings and Sheets if you want to sync that.

For a comprehensive step by step install walkthrough see the Getting started with google-drive-source slide deck. You don't need to use this with Gatsby, that's just the example.

Install

npm install --save google-drive-source

Configuration

In your package.json file add the following to the "scripts" key

    "gds": "google-drive-source",
    "gds:debug": "DEBUG=gDS google-drive-source"

If you have a build script, you could combine them with concurrently so you download your latest pages just prior to building and keep them updating throughout.

  "build:gds": "concurrently 'npm run gds' 'npm run build' "

By default the gds script runs once and fetches a list of files in the folder specified and checks for changes. If no changes, it terminates. If changes occured, it will fetch only the docs and images that changed and then terminate.

If you want to have it run at an interval, you can set a WAIT in minutes at the command line. If you want it to wait 10 minutes, use WAIT=10 npm run gds. If you want it to wait about 10 seconds, you can use WAIT=0.16 npm run gds.

Two things to note and one bug

• If you check too often, you may start stacking up request for the same file.
• Since Google Docs are always saving, updates can happen in the middle of an edit so make sure you run gds one last time before you publish to make sure you have the latest.
• Now the bug, I have noticed in testing that sometimes Google Docs get stuck. They end up with a 0 byte size. I believe this is on the Google side related to the item being out of sync between datacenters or something. I have not found a pattern to this issue yet and gds will retry 0 byte files but sometimes it can take awhile for it to download correctly.

Config files

You need to create two files in the root of your project. gds-auth.json

gds-config.json

Add these files to your .gitignore now!

gds-auth.json is your Google API Service Account Key file.

Your Service Account Key downloaded from the Google API Dashboard, e.g. (subject to change at Googles whim):

From the Google API Console

• Make a new project
  • Credentials tab
  • Create Credentials
  • Service Account Keys
  • Select Service Account "New Service Account"
  • Key Type: JSON
  • Assign local part of email address. You will use this email address to share folders and files. Make this something you will recognize when reviewing your Drive shares later.
  • This only needs "read" access
  • Download
  • Go to Library
  • Search for Drive and select it
  • Click "Enable"

In your Google drive, create or find a folder with some docs for your blog-posts and share it with the email address from your token above. This folder should contain all of the same kind of docs. Make note of the folder id (everything after the "/" in the folders URL).

Repeat for as many folders as you want for source. One option might be if you had multiple team members working independently but contributing to the same project, you could have each manage their own blog post folder and share it with the same email address and add it to the config.folders array.

gds-config.json is your config file

Options:

• Global options:

• outputRoot: Required - path from root of project to first level of folders. Minimum entry is "./"

• folders: Required - an array. At least one folder is required.

• Folder options:

• localFolder: Required - sub-folder of outputRoot. Minimum entry is "/"

• folderId: Required - Google Drive folder id from folders URL that was shared with the service account email

• docType: defaults to "md" downloads Google docs as text and adds ".md" file extension, other options are:

• "csv" download the first page of a Google sheet as csv

• "drawingImg": download Google drawings as png

• "drawingSvg": download Google drawings as svg

• "html" download a Google doc as html

• "js" download a Google doc as text and save with .js extension

• "json" download a Google doc as text and save with .json extension

• "media" download images and video

• "text" download Google doc as txt

• defaultSize: number of files to download in folder, defaults to 100

Usage

At the command line:

npm run gds normal mode, runs every minute

WAIT=5 npm run gds runs gds every 5 minutes

npm run gds:debug debug mode with extra logging

Example files

gds-auth.json

{
  "type": "service_account",
  "project_id": "some-crazy-name",
  "private_key_id": "some-uri-blahblahblah",
  "private_key": "-----BEGIN PRIVATE KEY-----\nsomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthingheresomelongthinghere\n-----END PRIVATE KEY-----\n",
  "client_email": "THE_EMAIL_ADDRESS_YOU_SHARE_YOUR_FOLDERS_WITH",
  "client_id": "1234567890987654321",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://accounts.google.com/o/oauth2/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/blahblahblahblahinhere.iam.gserviceaccount.com"
}

gds-config.json

{
  "outputRoot": "./src/pages/",
  "folders": [
    {
      "localFolder": "blog-posts/",
      "folderId": "1XXXXXXXXXXXXXXXXXXXXXXXXXX"
    },
    {
      "localFolder": "blog-posts/images/",
      "folderId": "2XXXXXXXXXXXXXXXXXXXXXXXXXX",
      "docType": "media"
    },
    {
      "localFolder": "blog-posts/text/",
      "folderId": "3XXXXXXXXXXXXXXXXXXXXXXXXXX",
      "docType": "text"
    },
    {
      "localFolder": "blog-posts/html/",
      "folderId": "4XXXXXXXXXXXXXXXXXXXXXXXXXX",
      "docType": "html"
    }
  ]
}

Todo

• Concurrent downloads (right now runs serially on purpose, see note below)
• Add tests

Code notes:

asyncForEach

Intentionally serially calling each item to keep from overwhelming the google api with too many request which results in empty files and errors. May come back to this implementation later but at least this is easy to read and understand.

Need to investigate the maximum concurrent connections to the api and work back from there. The folders still run in parallel so if a lot of different folders are added, there may still be some connection issues.

const asyncForEach = async (array, callback) => {
  for (let index = 0; index < array.length; index += 1) {
    await callback(array[index], index, array); // eslint-disable-line no-await-in-loop
  }
};