Auto-Update Client Apps

TL;DR

This guide shows you how to automatically update client applications installed on users’ computers. We’ll cover checking for updates, downloading them, and installing them without needing the user to do anything manually.

1. Choose an Update Method

There are several ways to handle auto-updates. Here are a few common options:

• Built-in Updater: Some frameworks (like Electron, .NET’s ClickOnce) have built-in update mechanisms. This is often the easiest option if your app uses one of these.
• Dedicated Update Library: Libraries like Squirrel.Windows or Sparkle (for macOS) provide more control and features.
• Custom Solution: You can build your own updater, but this requires significantly more effort. We’ll focus on using a dedicated library as it offers the best balance of control and simplicity.

2. Setting up Squirrel.Windows (Example)

Squirrel.Windows is a popular choice for Windows applications.

2.1 Install the NuGet Package

In Visual Studio, use the NuGet Package Manager to install Squirrel.Windows into your project:

Install-Package Squirrel.Windows

2.2 Configure Your Application

Add the following code to your application’s startup (e.g., in Main()):

using Squirrel; 

// ... other setup code ...

SquirrelSetup.Initialize(() => {
    return new UpdateManifest()
    {
        Identifier = "YourAppName",
        Version = Assembly.GetExecutingAssembly().GetName().Version,
    };
});

Replace "YourAppName" with a unique identifier for your application.

2.3 Create an Update Manifest

The update manifest (UpdateManifest) describes the new version of your app. Squirrel will automatically handle creating this file during the build process when you publish your application.

3. Creating and Publishing Updates

3.1 Build Your Updated Application

Increment the version number in your project’s properties (e.g., AssemblyInfo.cs).

3.2 Publish Your Application

When you publish your application, Squirrel will automatically create an update package and upload it to a designated location. You can configure this location in your project settings.

• Local Folder: For testing, you can publish to a local folder.
• Cloud Storage (AWS S3, Azure Blob Storage): Recommended for production.

4. Update Checking

Squirrel automatically checks for updates periodically in the background.

4.1 Configure Check Interval

You can configure how often Squirrel checks for updates using settings files or command-line arguments during installation.

5. Handling Updates

When a new update is found, Squirrel will:

• Download the update package.
• Restart your application (after prompting the user if necessary).
• Install the update.

6. Testing Your Auto-Update System

1. First Run: Install the initial version of your application.
2. Increment Version: Build a new version with an incremented version number.
3. Publish Update: Publish the updated application package to your chosen location.
4. Verify Update: The application should automatically detect and install the update after the configured check interval.

7. Important Considerations

• Code Signing: Sign your application code to ensure its authenticity and prevent tampering.
• Error Handling: Implement robust error handling to gracefully handle update failures.
• Rollback Mechanism: Consider implementing a rollback mechanism in case an update causes issues.
• User Experience: Provide clear feedback to the user during the update process.