Run Fediverse system tests with your application in a UBOS container

Here is an outline of the steps you need to take so your own Fediverse App can be tested like Mastodon is in the system test setups described in Getting a taste of FediTest. Just like there, this allows you to run your own App against itself, but also against other apps like Mastodon or WordPress with the plugins.

Step 1: Package your app for UBOS

This involves creating an Arch Linux package for it with extra metadata, and template files or scripts that can parameterize the configuration so that UBOS Gears can successfully deploy your App at any hostname.

The ubos.net website has tutorials for how to do that.

As a side effect, your App can now also be installed, uninstalled, backed up, and restored with a single command each, which may be an attractive feature anyway independent of FediTest.

Step 2: Create a NodeDriver implementation class for your app

When you specify Nodes in test Constellations, you specify a Node Driver like this:

{
    "nodedriver" : "MastodonUbosNodeDriver"
}

This name refers to a Python class that implements the FediTest NodeDriver abstract class (in src/feditest/nodedrivers/__init__.py). This NodeDriver abstract class defines a handful of methods that need to implemented for your App so FediTest can get an instance of your App up and running, and also take it back down.

As an example, you can use the MastodonUbosNodeDriver (which is found in src/feditest/nodedrivers/mastodon/ubos.py). Implement something similar that works for your App.

Step 3: Create a Node implementation class for your app

The NodeDriver class wants to instantiate subclass of Node in its _instantiate_ubos_node() method. You need to implement a subclass of Node for your App, too.

Class Node has many (abstract) subclasses, each of which provides methods that allow FediTest scripts to make the Node do something, or report back an observation. There is one such subclass per protocol. If, for example, you want your Node to be tested as a WebFinger server, you implement Node subclass WebFingerServer. If it is a full-fledged Fediverse Node, you implement subclass FediverseNode (that inherits from WebFingerServer), as class MastodonNode does.

This can be a little involved, because there are many things tests want to test. If your App implements the Mastodon API, you are in relative luck, because you can simply reuse the NodeWithMastodonAPI class, as we do in the support for WordPress (see class WordPressPlusPluginsUbosNode).