IRC Bridge Docs: Charm Architecture

charm
1

Charm architecture

The IRC Bridge facilitates communication between Matrix (Synapse) and IRC by acting as a bridge. It runs on a Juju model alongside HAProxy (load balancer) and PostgreSQL (database).

IRC Bridge is installed as a Snap in the Juju Machine unit and the charm interacts with it when the required integrations are set.

C4Component
title Component diagram for IRC bridge Charm

System_Boundary(imagebuildercharm), "IRC Bridge") {
  Component(charm, "IRC Bridge", "", "Observes events")
  Component(snap, "IRC Bridge snap", "", "Handle IRC Bridge application")

  Rel(charm, snap, "")
}
  1. The Charm is deployed.
  2. The Charm checks for database integration; if none is found, it transitions to a blocked state.
  3. The Charm checks for Matrix authentication integration; if none is found, it transitions to a blocked state.
  4. The Charm validates the configuration; if invalid, it transitions to a blocked state.
  5. If Ident is enabled, the Ident port is configured to be exposed.
  6. Once all integrations and validations are complete, the Charm installs the Snap and generates the necessary configuration.
  7. From the Matrix authentication integration, the Charm creates the IRC registration file and shares it with Synapse, which then registers the IRC Bridge as an application service.

IRC bridge snap

The IRC Bridge Snap is utilized to package and distribute matrix-appservice-irc, providing a consistent, secure and maintainable deployment across various environments. By leveraging Snap, the application benefits from simplified installation, automatic updates and dependency isolation.

For more details or to participate in its development, please refer to the GitHub repository.

Charm code overview

The src/charm.py is the default entry point for a charm and has the IRCCharm Python class which inherits from the CharmBase.

CharmBase is the base class from which all Charms are formed, defined by Ops (Python framework for developing charms).

See more information in Charm.

The __init__ method guarantees that the charm observes all events relevant to its operation and handles them.

Note that the IRC Bridge is a machine charm, meaning it may differ from a Kubernetes charm in various ways. You can learn more about this in the Charm Taxonomy.