Adding a notifier

Notifiers live in src/notify/:

• Directorysrc/notify/

  • mod.rs Notifier trait, NotifierConfig, Event
  • discord.rs
  • webhook.rs
  • slack.rs your new notifier

1. Create src/notify/slack.rs with a struct that implements the Notifier trait: label() and send(&Event).

2. Register it in src/notify/mod.rs:

   • add mod slack;
   • add a Slack { ... } variant to NotifierConfig with the settings it needs
   • add an arm to the match in NotifierConfig::build

The variant’s fields are what users write in their [[serve.notify]] table (type = "slack" plus those fields). If its main setting is called url, the --notify slack=<url> shorthand works with no extra code.

A starting point

The generic webhook notifier is the smallest one to copy:

src/notify/webhook.rs

use anyhow::Result;

use super::{BoxFuture, Event, Notifier, parse_http_url, post_json};

pub struct Webhook {
    url: reqwest::Url,
    http: reqwest::Client,
}

impl Webhook {
    pub fn new(target: &str, http: reqwest::Client) -> Result<Self> {
        Ok(Self {
            url: parse_http_url(target)?,
            http,
        })
    }
}

impl Notifier for Webhook {
    fn label(&self) -> String {
        // Host only: the path or query string may carry a token.
        format!("webhook ({})", self.url.host_str().unwrap_or("?"))
    }

    fn send<'a>(&'a self, event: &'a Event) -> BoxFuture<'a, Result<()>> {
        Box::pin(post_json(&self.http, &self.url, event))
    }
}

Rules of thumb

• Never log the URL. label() should only show something safe, like the host.
• Respect the key. The event only carries key for notifiers with include_key. Don’t send it anywhere else.
• Escape user content. Torrent names are untrusted. The Discord notifier escapes markdown and turns mentions off.

New events

New kinds of events (e.g. “client finished downloading”) are variants of the Event enum, and each notifier decides how to render them.