snapcraft

Reviewing pull requests for snaps has been pretty terrible ever since snaps were introduced. There are a few very simple reasons: Building snaps locally in order to review is too much work. This is a fine place to start, but it doesn’t scale, especially if it takes any amount of time to build the snap in question (mine takes over an hour). Most CI engines use Docker. You can build snaps in docker with hacks and tweaks that sort of work sometimes, but it’s not a supported approach, and it’ll just randomly break next week....

The snapcraft CLI (the tool used to create snaps) has long had support for building snaps that use both ROS 1 and ROS 2. ROS 2 Foxy Fitzroy is the latest ROS 2 LTS, which runs on Ubuntu 20.04 (Focal Fossa). The snapcraft CLI recently gained experimental support for building Foxy snaps, so I wanted to walk you through doing exactly that with the goal of helping both of us: getting you familiar with this new feature, and at the same time getting some mileage on this so as to make it not experimental....

I’ve had a very particular itch for a long time, now. Something I love about open source is that it empowers developers to scratch their own itches, and a while back I decided to do exactly that. We’ve used it in production on the Nextcloud snap for a few months with relatively few issues, so I think it’s time to open it up for wider use… in case you share my itch....

A while back I wrote a post about distributing a ROS system among multiple snaps. If you want to enable some sort of add-on story, you need to have multiple snaps, and that remains the way to do it today with ROS. That approach works, but I’ll be the first to admit that it’s not terribly elegant, and we’re working on making it better. However, in my experience talking to various ROS users creating snaps, they oftentimes end up using multiple snaps not for an add-on or app store story, but for build speed....

The snapcraft CLI has supported building ROS1 snaps for a while via the catkin plugin. We supported the ROS2 betas via the ament plugin, but that was before Open Robotics had a ROS 2 package repository setup, which meant that the ament plugin built the ROS 2 underlay from source, and it was predictably dreadfully slow. However, the stable releases of ROS2 introduced a new build system called colcon, and also had their own package repositories setup....