From a05128d215529422a7424f1265f53010620ace59 Mon Sep 17 00:00:00 2001
From: Jonni Liljamo <jonni@liljamo.com>
Date: Mon, 24 Nov 2025 23:41:43 +0200
Subject: [PATCH] feat: alertmanager webhook route

---
 src/main.rs                |  9 +++++
 src/routes/alertmanager.rs | 77 ++++++++++++++++++++++++++++++++++++++
 src/routes/mod.rs          |  1 +
 3 files changed, 87 insertions(+)
 create mode 100644 src/routes/alertmanager.rs

diff --git a/src/main.rs b/src/main.rs
index 53a98cf..1180a26 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -76,6 +76,15 @@ async fn main() {
                 move |headers, body| routes::message::message(shared_state, headers, body)
             }),
         )
+        .route(
+            "/alertmanager/v4",
+            post({
+                let shared_state = Arc::clone(&state);
+                move |headers, body| {
+                    routes::alertmanager::alertmanager_v4(shared_state, headers, body)
+                }
+            }),
+        )
         .layer(TraceLayer::new_for_http())
         .with_state(state);
 
diff --git a/src/routes/alertmanager.rs b/src/routes/alertmanager.rs
new file mode 100644
index 0000000..a88a011
--- /dev/null
+++ b/src/routes/alertmanager.rs
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2025 Jonni Liljamo <jonni@liljamo.com>
+ *
+ * This file is licensed under AGPL-3.0-or-later, see NOTICE and LICENSE for
+ * more information.
+ */
+
+use std::{collections::HashMap, sync::Arc};
+
+use axum::{Json, http::HeaderMap, response::IntoResponse};
+use reqwest::StatusCode;
+use serde::Deserialize;
+
+use crate::{
+    routes::{extract_token, message::MessageForm},
+    state::State,
+};
+
+const ALERTMANAGER_JSON_VERSION_4: &str = "4";
+
+#[derive(Debug, Deserialize)]
+pub struct V4Alert {
+    annotations: HashMap<String, String>,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct V4Form {
+    version: String,
+    alerts: Vec<V4Alert>,
+}
+
+impl From<V4Alert> for MessageForm {
+    fn from(value: V4Alert) -> Self {
+        MessageForm {
+            title: value
+                .annotations
+                .get("summary")
+                .cloned()
+                .unwrap_or("Summary N/A".into()),
+            message: value
+                .annotations
+                .get("description")
+                .cloned()
+                .unwrap_or("Description N/A".into()),
+            format_commonmark: false,
+        }
+    }
+}
+
+pub async fn alertmanager_v4(
+    state: Arc<State>,
+    headers: HeaderMap,
+    Json(message): Json<V4Form>,
+) -> impl IntoResponse {
+    let token = extract_token!(headers).trim_start_matches("Bearer ");
+
+    let notifier = match state.find_notifier(token) {
+        Some(n) => n,
+        None => return (StatusCode::UNAUTHORIZED, "unauthorized"),
+    };
+
+    if message.version != ALERTMANAGER_JSON_VERSION_4 {
+        return (
+            StatusCode::BAD_REQUEST,
+            "wrong alertmanager json version, this API is for version 4",
+        );
+    }
+
+    for alert in message.alerts {
+        if let Err(err) = state.send_message(notifier, &alert.into()).await {
+            tracing::error!(?err, "message sending failed");
+            return (StatusCode::INTERNAL_SERVER_ERROR, "failed to send message");
+        };
+    }
+
+    (StatusCode::OK, "")
+}
diff --git a/src/routes/mod.rs b/src/routes/mod.rs
index c22fbb6..63cded6 100644
--- a/src/routes/mod.rs
+++ b/src/routes/mod.rs
@@ -5,6 +5,7 @@
  * more information.
  */
 
+pub mod alertmanager;
 pub mod message;
 
 macro_rules! extract_token {
-- 
2.44.1