Title: Export Flatpak programs from a computer to another

	Title: Export Flatpak programs from a computer to another
	Author: Solène
	Date: 01 January 2023
	Tags: linux flatpak bandwidth
	Description: In this article, you will learn how to use Flatpak to
	export an installed program to another Linux system.

	# Introduction

	As a flatpak user, but also someone with a slow internet connection, I
	was looking for a way to export a flatpak program to install it on
	another computer. It turns out flatpak supports this, but it's called
	"create-usb" for some reasons.

	So today, I'll show how to export a flatpak program from a computer to
	another.

	Flatpak official website
	Flatpak documentation about usb drives

	# Pre-requisites

	For some reasons, the default flathub parameters doesn't associate it a
	"Collection ID", which is required for the create-usb feature to work,
	so we need to associate a "Collection ID" to the flathub remote
	repository on both systems.

	We can use the example from the official documentation:

	```
	flatpak remote-modify --collection-id=org.flathub.Stable flathub
	```

	# Export

	The export process is simple, create a directory in which you want the
	flatpak application to be exported, we will use `~/export/` in the
	examples, with the program `org.mozilla.firefox`.

	```
	flatpak create-usb ~/export/ org.mozilla.firefox
	```

	The export process will display a few lines and tell you when it
	finished.

	If you export multiple programs into the same directory, the export
	process will be smart and skip already existing components.

	# Import

	Take the `~/export/` directory, either on a USB drive, or copy it using
	rsync, share it over NFS/Samba etc... It's up to you. In the example,
	`~/export/` refers to the same directory transferred from the previous
	step onto the new system.

	Now, we can run the import command to install the program.

	```
	flatpak install --sideload=~/export/.ostree/repo/ flathub org.mozilla.firefox
	```

	If it's working correctly, it should be very fast.

	# Limitation

	Because the flatpak components/dependencies of a program can differ
	depending on the host (for example if you have an NVIDIA card, it will
	pull some NVIDIA dependencies), so if you export a program from a
	non-NVIDIA system to the other, it won't be complete to work reliably
	on the new system, but the missing parts can be downloaded on the
	Internet, it's still reducing the bandwidth requirement.

	# Conclusion

	I kinda like Flatpak, it's convenient and reliable, and allow handling
	installed programs without privileges escalation. The programs can be
	big, it's cool to be able to save/export them for later use.