Snapcraft Guide (Ubuntu Software Center & More)

This guide provides information on how to package your Electron application for any Snapcraft environment, including the Ubuntu Software Center.

Background and Requirements

Together with the broader Linux community, Canonical aims to fix many of the common software installation problems with the snapcraft project. Snaps are containerized software packages that include required dependencies, auto-update, and work on all major Linux distributions without system modification.

There are three ways to create a .snap file:

1) Using electron-forge or electron-builder, both tools that come with snap support out of the box. This is the easiest option. 2) Using electron-installer-snap, which takes electron-packager's output. 3) Using an already created .deb package.

In all cases, you will need to have the snapcraft tool installed. We recommend building on Ubuntu 16.04 (or the current LTS).

snap install snapcraft --classic

While it is possible to install snapcraft on macOS using Homebrew, it is not able to build snap packages and is focused on managing packages in the store.

Using electron-installer-snap

The module works like electron-winstaller and similar modules in that its scope is limited to building snap packages. You can install it with:

npm install --save-dev electron-installer-snap

Step 1: Package Your Electron Application

Package the application using electron-packager (or a similar tool). Make sure to remove node_modules that you don't need in your final application, since any module you don't actually need will increase your application's size.

The output should look roughly like this:

.
  └── dist
      └── app-linux-x64
          ├── LICENSE
          ├── LICENSES.chromium.html
          ├── content_shell.pak
          ├── app
          ├── icudtl.dat
          ├── libgcrypt.so.11
          ├── libnode.so
          ├── locales
          ├── natives_blob.bin
          ├── resources
          ├── v8_context_snapshot.bin
          └── version

Step 2: Running electron-installer-snap

From a terminal that has snapcraft in its PATH, run electron-installer-snap with the only required parameter --src, which is the location of your packaged Electron application created in the first step.

npx electron-installer-snap --src=out/myappname-linux-x64

If you have an existing build pipeline, you can use electron-installer-snap programmatically. For more information, see the Snapcraft API docs.

const snap = require('electron-installer-snap')
  
  snap(options)
    .then(snapPath => console.log(`Created snap at ${snapPath}!`))

Using an Existing Debian Package

Snapcraft is capable of taking an existing .deb file and turning it into a .snap file. The creation of a snap is configured using a snapcraft.yaml file that describes the sources, dependencies, description, and other core building blocks.

Step 1: Create a Debian Package

If you do not already have a .deb package, using electron-installer-snap might be an easier path to create snap packages. However, multiple solutions for creating Debian packages exist, including electron-forge, electron-builder or electron-installer-debian.

Step 2: Create a snapcraft.yaml

For more information on the available configuration options, see the documentation on the snapcraft syntax. Let's look at an example:

name: myApp
  version: '2.0.0'
  summary: A little description for the app.
  description: |
   You know what? This app is amazing! It does all the things
   for you. Some say it keeps you young, maybe even happy.
  
  grade: stable
  confinement: classic
  
  parts:
    slack:
      plugin: dump
      source: my-deb.deb
      source-type: deb
      after:
        - desktop-gtk3
      stage-packages:
        - libasound2
        - libgconf2-4
        - libnotify4
        - libnspr4
        - libnss3
        - libpcre3
        - libpulse0
        - libxss1
        - libxtst6
    electron-launch:
      plugin: dump
      source: files/
      prepare: |
        chmod +x bin/electron-launch
  
  apps:
    myApp:
      command: bin/electron-launch $SNAP/usr/lib/myApp/myApp
      desktop: usr/share/applications/myApp.desktop
      # Correct the TMPDIR path for Chromium Framework/Electron to ensure
      # libappindicator has readable resources.
      environment:
        TMPDIR: $XDG_RUNTIME_DIR

As you can see, the snapcraft.yaml instructs the system to launch a file called electron-launch. In this example, it passes information on to the app's binary:

#!/bin/sh
  
  exec "$@" --executed-from="$(pwd)" --pid=$$ > /dev/null 2>&1 &

Alternatively, if you're building your snap with strict confinement, you can use the desktop-launch command:

apps:
    myApp:
      # Correct the TMPDIR path for Chromium Framework/Electron to ensure
      # libappindicator has readable resources.
      command: env TMPDIR=$XDG_RUNTIME_DIR PATH=/usr/local/bin:${PATH} ${SNAP}/bin/desktop-launch $SNAP/myApp/desktop
      desktop: usr/share/applications/desktop.desktop