This project is written in C# using .NET 8.
Christofel is a modular Discord bot using Remora.Discord.
To run Christofel application locally, first database has to be started. For that either Nix or Docker can be used.
For using nix, there is a flake.nix in this repository. It contains
services-flake services. To start these services use
nix run .#christofel-services. This will start the database,
configure initial database, and user. Lastly, it will apply
migrations. Observe output of all of the processes to see
if everything succeeded. The migration process needs to be able to
build the project. The database created is bound to localhost:3306.
The user is christofel, its password is also christofel, and the
database is named christofel as well.
To run the application, it's necessary to create a basic config.json.
An example is in docker/config.json. What it has to contain depends on
the plugins you are going to be running.
Christofel is a bot that is used on CTU FEE (Czech technical university, Faculty of electrical engineering) Discord server.
It is used for basic moderation and for authentication of the users using oauth2.
Christofel can attach (and detach) plugins during runtime at time. All of the plugins that are used on our server are in this repository.
Christofel uses Remora.Discord along with some Microsoft extensions (namely Configuration, DependencyInjection, Logging).
The main feature of library (and base application) is to be able to attach plugins during runtime.
The library can be found in Christofel.Plugins, Christofel.Plugins.Abstractions projects. This should be a library that every
plugin will reference. To attach a plugin, it must have a class implementing IPlugin. For more
information about how to setup a plugin, documentation can be used.
Another important library is Christofel.Common. It exposes interfaces that hold the shared state of the application.
That means the bot itself for interacting with Discord, LoggerFactory, database context, permissions and more.
Optionally Christofel.Helpers may be used for some common operations and Christofel.CommandsLib when commands
should be used in the given plugin.
Christofel.Application is a project containing startup of Christofel, it manages its lifetime and
supports attaching plugins using a command and/or loads them at startup depending on the configuration.
The application contains implementations of some of the interfaces that are in base library. These implementations
are hidden from other plugins, they should not reference the application.
The most important thing about attaching plugins is that only those libraries that are needed to be shared
are shared and the rest is loaded using a different context. That means that every plugin can have different
version of the same library that is used in another plugin. Shared libraries may be specified, and by default,
only Christofel.Common library has to be shared.
Each plugin has its lifetime that exposes some CancellationTokens for registering callbacks and a method to stop and destroy the plugin (or application). In case of an error, it should be reported back to the main application. The plugins that are detached will be erased from the memory eventually, but it may take some time, so reattaching a plugin multiple times may leave higher memory usage for a while.
Christofel library could be used without our plugins for CTU FEE server so it may become usable on different servers. At some point Nuget libraries may be made and the projects may be splitted to multiple repositories.