Yes, this is what this repository is about!

In this repository is everything you need to have in order to make Windows Auto Update work. Which is:

• Electron
• Electron packager (builder), I use electron-builder which can build all the platform just on Mac
• Some index.html file that Electron can load and where it boots electron.autoUpdater

We don't quite need to know much about how this works behind the scenes but just to clarify some terms.

electron-builder uses Squirrel. That is a packager that is capable of automatical build of setup files for .exe binaries.

You need a installer because just bold .exe files cannot be auto update with Electron. You need to packager capable of calling Squirrel.

Of course Squirrel is a Windows application, that's why you still need some runtime. On Linux or Mac you can simply use Wine.

I would follow this perfect tutorial on how to install Wine on the mac via brew: https://www.davidbaumgold.com/tutorials/wine-mac/.

The update process itself is based on .nupkg packages which is a binary format similar to .zip and holds source code of your application.

Squirell generates your-app-1.0.0-full.nupkg which is complete application binary and if it's possible it also generates a file called your-app-1.0.0-delta.nupkg.

This *-delta.nupkg is immportant for auto updates. This file holds patch that needs to be applied to previous version of your app to update to the next version.

So how you force electron-builder to create such file for you? The key is the RELEASES file. This file is always generated by Squirrel. It is a simply list of available app versions with checksums and names of *.nupkg files for every version.

Alright, first. Make sure you already are on Windows machine and if not, just download and install Wine - Mac guide here. You will also need to install mono which can be installed through homebrew.

brew install mono

Once you are ready with this, you can install this repo:

npm install
//or
yarn install

Alright, verify that everything works by starting prebuilt of our app:

npm start

Such app, right? Note that version number is dynamic and will change when we update our app.

Let's try to create a Windows build I prepared for you:

npm run build

Alright this fails. The reason is that I already added a line that tells Squirrel where it should find all my app releases in RELEASES file.

We have not yet built any Windows app, so let's just delete one line from package.json. Note that electron-builder uses package.json to configurate the build, and so far I got everything I needed, no programming required.

// delete this line:
"remoteReleases": "http://localhost:9000/dist/win1/"

//lets do the build again
npm run build

Now everything should go OK. You may have troubles with Wine. Make sure you did the steps described above.

NOTE that in package.json this part:

"win": {
  "certificateFile": "./certs/my_signing_key.pfx",
  "certificatePassword": ""
}

I generated dummy certificates to sign this app, if you don't provide these files, autoUpdate will not work! Replace these lines with your own certificate info. Guide to generate such certificates is here: https://www.npmjs.com/package/electron-installer-windows

So what do we have now? Well, in dist/win there is something like electron-windows-autoupdate-1.0.0-full.nupkg which is a packed binary. Along with electron-windows-autoupdate Setup 1.0.0 which is Windows installer of our App. Great.

If you don't like the file names, just change name key in package.json, so that it suits your needs.

The most important part to make Windows AutoUpdate work is however this simple text file RELEASES (dist/win/RELEASES).

This file is the key to create *-delta.nupkg files needed for auto update. Squirrel must be able to find this file, unfortunately electron-builder only support web links to releases file in config, but we are programmers, right? No problem for us.

So now is the task to make folder dist/win accesable over internet. In production, you would probably upload all this artifacts from dist/win to S3 bucket or whatever, and just pasted the links. Well, in dev mode, we would be OK just with SimpleHTTPServer which is shipped on Mac as well as on Linux and Windows if you download python. You can of course use any other server, that can server static files, express, webpack, apache, nginx whatever. The only requirement is that we have a web url that points to dist/win.

So firstly. Rename dist/win to some other name I use dist/win1. The reason for renaming is that the electron-builder will overwrite folder dist/win with all it's content and we want to keep it for auto update, so renaming make sure that everything is OK.

Then just:

// start server here
python -m SimpleHTTPServer 9000

// or just
npm run start:server

So now if you do:

open http://localhost:9000/dist/win1/RELEASES

It should open RELEASES in the browser, maybe it downloads it. Anyway everything but 404 is OK.

So now we have to tell Squirrel that we already have some versions of our app built and we want another version to be an update of older ones.

To do that, just bump version in package.json to eg. 2.0.0. If you won't bump version, new build will not be an update of previous version.

Now let's put back that line we deleted from electron-builder config in package.json.

So your key build in package.json should look like this.

"build": {
  "squirrelWindows": {
    "remoteReleases": "http://localhost:9000/dist/win1/"
  },
  "win": {
    "certificateFile": "./certs/my_signing_key.pfx",
    "certificatePassword": ""
  }
},

NOTE that in remoteReleases you just specify path to folder where RELEASES and *-*.nupkg files are, not path to individial files!

So run again the build script:

// make sure serve runs in root of this repo
// npm run start:server
npm run build

Now in dist folder there should be dist/win and dist/win1

And to verify that Squirell seen previous RELEASES, take a look into dist/win/RELEASES. And here you should see something like this:

CF1472BFD1F777AAE09501313AA55A7C080CD620 electron-windows-autoupdate-1.0.0-full.nupkg 54575243
7CD4A1765DF084BFE36FC615A63D05DA3CB89ABD electron-windows-autoupdate-2.0.0-delta.nupkg 34921
A94689C1884E9ED50963BFF58ED974AA4D17EEA1 electron-windows-autoupdate-2.0.0-full.nupkg 54576239

If there is just one line, it means that you did not bump version in package.json.

If you have 3 lines, than great, Squirrel noticed previous version and created *-delta.nupkg which holds difference between older version and current. There is also a note about *-full.nupkg which is package binary of the next version of your app that you just built.

So now all the update files are prepared we may implement app code that will implement auto update in the app.

All the magic you can see in index.html.

Things to notice are:

• auto update event listener registered by autoUpdate.on()
• most important event is update-downloaded, after this event you can install the udpate
• autoUpdater.setFeedURL() which I may get to
• finally autoUpdater.checkForUpdates() that is all you need to do to check for update and download it
• and of course autoUpdater.quitAndInstall() called after update-downloaded is fired

Note this line autoUpdater.setFeedURL('http://localhost:9000/dist/win/'). AutoUpdater uses Squirrel in the background, so it requires URL to folder where all the required files are located. These files are familiar *-full/delta.nupkg and RELEASES.

But this time, this url must poin to folder where update files are located.

So in our case, we have old update files in dist/win1 but files for newer version (along with RELEASES with all the versions) is in dist/win.

So now this time on Windows machine, because we will try install and auto update our app, we have to start a server that would point to dist/win and set autoUpdater.setFeedURL() accordingly.

We can copy update files to windows machine, or upload them to the web, and set the url, so that it points to the folder with *.nupkg and RELEASES.

You can use SimpleHTTPServer again even on Windows, just make sure you have python installed and in your PATH.

You can clone this repo and run:

npm run start:server

Again and it should all work.

Now, this is the time to run windows installer, but make sure you install the first version from dist/win1/*Setup<version>.exe!!

Once done, you should see Current version is: 1.0.0 in our awesome app. Also you should see some logs in console saying that an update is available, then that the update is available, being downloaded and finally an alert pop ups, confirm it and App will automaticaly update!!

Now you see Current version is: <BUMPED VERSION>

Make sure that dist/win is accesible via browser on your Windows machine. Make sure you have correct url set on updater by calling autoUpdater.setFeedURL().

Make sure server is running and in package.json correct "remoteReleases" is set.

Code sign was not applied, take a look here how to generate one: https://www.npmjs.com/package/electron-installer-windows

Just ask! [email protected]!