How to use the command flatpak-builder (with examples)

Flatpak-builder is a command-line tool that helps in building and managing Flatpak applications. It automates the process of building and exporting Flatpak packages, making it easier for developers to create and distribute their applications in a cross-distribution manner. This article provides examples of different use cases of the flatpak-builder command.

Use case 1: Build a Flatpak and export it to a new repository

Code:

flatpak-builder path/to/build_directory path/to/manifest

Motivation: This use case is helpful when you want to build a Flatpak application and export it to a new repository. It creates a new repository in the specified build_directory and adds the built application to it.

Explanation:

• path/to/build_directory is the directory where the repository will be created.
• path/to/manifest is the path to the manifest file (*.json) that describes the application.

Example output:

Building application in path/to/build_directory
Exporting to repository in path/to/build_directory/repo...
Application built and exported successfully!

Use case 2: Build a Flatpak and export it to the specified repository

Code:

flatpak-builder --repo=repository_name path/to/build_directory path/to/manifest

Motivation: This use case is useful when you want to build a Flatpak application and export it directly to a specified repository. It saves you the extra step of manually moving the built application to the desired repository.

Explanation:

• --repo=repository_name specifies the name of the existing repository where you want to export the built Flatpak.
• path/to/build_directory is the directory where the repository will be created.
• path/to/manifest is the path to the manifest file (*.json) that describes the application.

Example output:

Building application in path/to/build_directory
Exporting to repository repository_name...
Application built and exported successfully!

Use case 3: Build a Flatpak and install it locally

Code:

flatpak-builder --install path/to/build_directory path/to/manifest

Motivation: This use case is helpful when you want to build a Flatpak application and install it locally for testing purposes. It saves you the step of manually installing the built application using the flatpak install command.

Explanation:

• --install tells flatpak-builder to install the built application locally.
• path/to/build_directory is the directory where the repository will be created.
• path/to/manifest is the path to the manifest file (*.json) that describes the application.

Example output:

Building application in path/to/build_directory
Installing application locally...
Application built and installed successfully!

Use case 4: Build and sign a Flatpak and export it to the specified repository

Code:

flatpak-builder --gpg-sign=key_id --repo=repository_name path/to/manifest

Motivation: This use case is useful when you want to build a Flatpak application, sign it with a GPG key, and export it directly to a specified repository. It ensures the authenticity and integrity of the application package.

Explanation:

• --gpg-sign=key_id specifies the GPG key identity to use for signing the application.
• --repo=repository_name specifies the name of the existing repository where you want to export the signed Flatpak.
• path/to/manifest is the path to the manifest file (*.json) that describes the application.

Example output:

Building application in path/to/build_directory
Signing with GPG key key_id...
Exporting to repository repository_name...
Application built, signed, and exported successfully!

Use case 5: Run a shell inside of an application sandbox without installing it

Code:

flatpak-builder --run path/to/build_directory path/to/manifest sh

Motivation: This use case is handy when you want to run a shell session inside the Flatpak application sandbox without installing the application. It allows you to interactively test and debug the application within the isolated environment.

Explanation:

• --run instructs flatpak-builder to run the application without installing it.
• path/to/build_directory is the directory where the repository will be created.
• path/to/manifest is the path to the manifest file (*.json) that describes the application.
• sh specifies the command to run inside the application sandbox. In this case, it starts a shell session.

Example output:

Building application in path/to/build_directory
Running application in sandbox...
Executing shell session...
Welcome to the application shell!

Conclusion:

Flatpak-builder is a powerful command-line tool for building and managing Flatpak applications. It simplifies the process of creating, exporting, signing, and running Flatpak packages. The examples provided in this article demonstrate the various use cases of flatpak-builder, enabling developers to efficiently build and distribute their applications using Flatpak.