alertmanager-gotify-bridge: initial commit with bridge and CI

.woodpecker.yaml

@@ -0,0 +1,24 @@
+labels:
+  arch: amd64
+
+when:
+  - event: tag
+    ref: "refs/tags/v*"
+
+steps:
+  - name: build-and-push
+    image: git.oleks.space/oleks/nix-ci:latest
+    environment:
+      REGISTRY_TOKEN:
+        from_secret: registry_token
+    commands:
+      - echo "$REGISTRY_TOKEN" | docker login git.oleks.space -u oleks --password-stdin
+      - docker buildx create --name amd64 --driver remote "tcp://buildkit-rootless-amd64.infra.svc.cluster.local:1234"
+      - TAG=$(echo "$CI_COMMIT_TAG" | sed 's/^v//')
+      - IMAGE="git.oleks.space/oleks/alertmanager-gotify-bridge"
+      - echo "Building $IMAGE:$TAG"
+      - docker buildx build --builder amd64 --platform linux/amd64 --tag "$IMAGE:$TAG" --tag "$IMAGE:latest" --push .
+    backend_options:
+      kubernetes:
+        nodeSelector:
+          kubernetes.io/hostname: howard2404

Dockerfile

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+FROM python:3.12-alpine
+COPY bridge.py /app/bridge.py
+WORKDIR /app
+EXPOSE 8080
+CMD ["python", "bridge.py"]

bridge.py

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+#!/usr/bin/env python3
+"""Alertmanager webhook receiver that forwards alerts to Gotify."""
+
+import json
+import os
+import sys
+from http.server import HTTPServer, BaseHTTPRequestHandler
+from urllib.request import Request, urlopen
+from urllib.error import URLError
+
+GOTIFY_URL = os.environ["GOTIFY_URL"]
+DISASTER_TOKEN = os.environ["DISASTER_TOKEN"]
+WARNING_TOKEN = os.environ["WARNING_TOKEN"]
+DISASTER_PRIORITY = int(os.environ.get("DISASTER_PRIORITY", "8"))
+WARNING_PRIORITY = int(os.environ.get("WARNING_PRIORITY", "4"))
+
+SEVERITY_MAP = {
+    "critical": (DISASTER_TOKEN, DISASTER_PRIORITY),
+    "warning": (WARNING_TOKEN, WARNING_PRIORITY),
+}
+
+
+def send_gotify(token, title, message, priority):
+    data = json.dumps({
+        "title": title,
+        "message": message,
+        "priority": priority,
+    }).encode()
+    req = Request(
+        f"{GOTIFY_URL}/message?token={token}",
+        data=data,
+        headers={"Content-Type": "application/json"},
+    )
+    try:
+        urlopen(req)
+    except URLError as e:
+        print(f"ERROR sending to Gotify: {e}", file=sys.stderr)
+
+
+class Handler(BaseHTTPRequestHandler):
+    def do_POST(self):
+        try:
+            length = int(self.headers.get("Content-Length", 0))
+            body = json.loads(self.rfile.read(length))
+        except (json.JSONDecodeError, ValueError) as e:
+            self.send_response(400)
+            self.end_headers()
+            self.wfile.write(f"Bad request: {e}".encode())
+            return
+
+        for alert in body.get("alerts", []):
+            severity = alert.get("labels", {}).get("severity", "warning")
+            token, priority = SEVERITY_MAP.get(severity, SEVERITY_MAP["warning"])
+            status = alert.get("status", "firing")
+            alertname = alert.get("labels", {}).get("alertname", "Unknown")
+            summary = alert.get("annotations", {}).get("summary", "")
+
+            prefix = "RESOLVED" if status == "resolved" else "FIRING"
+            title = f"[{prefix}] {alertname}"
+            message = summary or f"{alertname} is {status}"
+
+            send_gotify(token, title, message, priority)
+            print(f"Forwarded: {title} -> severity={severity} priority={priority}")
+
+        self.send_response(200)
+        self.end_headers()
+        self.wfile.write(b"ok")
+
+    def do_GET(self):
+        if self.path == "/health":
+            self.send_response(200)
+            self.end_headers()
+            self.wfile.write(b"ok")
+            return
+        self.send_response(404)
+        self.end_headers()
+
+    def log_message(self, format, *args):
+        print(format % args)
+
+
+if __name__ == "__main__":
+    port = int(os.environ.get("PORT", "8080"))
+    server = HTTPServer(("0.0.0.0", port), Handler)
+    print(f"Bridge listening on :{port}")
+    server.serve_forever()