Snapcraft Guide (Linux)

Snapcraft Guide (Linux)

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 some cases, you will need to have the snapcraft tool installed. Instructions to install snapcraft for your particular distribution are available here.

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
        ├── 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 `snapcraft` with `electron-packager`

Step 1: Create Sample Snapcraft Project

Create your project directory and add the following to snap/snapcraft.yaml:

name: electron-packager-hello-world
version: '0.1'
summary: Hello World Electron app
description: |
  Simple Hello World Electron app as an example
base: core18
confinement: strict
grade: stable
apps:
  electron-packager-hello-world:
    command: electron-quick-start/electron-quick-start --no-sandbox
    extensions: [gnome-3-34]
    plugs:
    - browser-support
    - network
    - network-bind
    environment:
      # Correct the TMPDIR path for Chromium Framework/Electron to ensure
      # libappindicator has readable resources.
      TMPDIR: $XDG_RUNTIME_DIR
parts:
  electron-quick-start:
    plugin: nil
    source: https://github.com/electron/electron-quick-start.git
    override-build: |
        npm install electron electron-packager
        npx electron-packager . --overwrite --platform=linux --output=release-build --prune=true
        cp -rv ./electron-quick-start-linux-* $SNAPCRAFT_PART_INSTALL/electron-quick-start
    build-snaps:
    - node/14/stable
    build-packages:
    - unzip
    stage-packages:
    - libnss3
    - libnspr4

If you want to apply this example to an existing project:

Replace source: https://github.com/electron/electron-quick-start.git with source: ..
Replace all instances of electron-quick-start with your project’s name.

Step 2: Build the snap

$ snapcraft
<output snipped>
Snapped electron-packager-hello-world_0.1_amd64.snap

Step 3: Install the snap

sudo snap install electron-packager-hello-world_0.1_amd64.snap --dangerous

Step 4: Run the snap

electron-packager-hello-world

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
      - 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

Snapcraft (Linux)