add grafana formatter

This was initially designed and implemented in #4

Co-authored-by: Sven Seeberg <mail@sven-seeberg.de>

CHANGELOG.md

@@ -6,6 +6,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- add grafana formatter
 - add formatted_body to bypass markdown with direct
   [matrix-custom-HTML](https://matrix.org/docs/spec/client_server/r0.6.1#m-room-message-msgtypes)
 - allow "key" to be passed as a parameter

matrix_webhook/__main__.py

@@ -16,7 +16,7 @@ from nio import AsyncClient
 from nio.exceptions import LocalProtocolError
 from nio.responses import RoomSendError
 
-from . import conf
+from . import conf, formatters
 
 ERROR_MAP = {"M_FORBIDDEN": HTTPStatus.FORBIDDEN}
 
@@ -46,6 +46,12 @@ async def handler(request):
     if "key" in request.rel_url.query and "key" not in data:
         data["key"] = request.rel_url.query["key"]
 
+    if "formatter" in request.rel_url.query:
+        try:
+            data = getattr(formatters, request.rel_url.query["formatter"])(data)
+        except AttributeError:
+            return create_json_response(HTTPStatus.BAD_REQUEST, "Unknown formatter")
+
     if not all(key in data for key in ["body", "key"]):
         return create_json_response(
             HTTPStatus.BAD_REQUEST, "Missing body and/or API key property"

matrix_webhook/formatters.py

@@ -0,0 +1,15 @@
+"""Formatters for matrix webhook."""
+
+
+def grafana(data):
+    """Pretty-print a grafana notification."""
+    text = ""
+    if "title" in data:
+        text = "### " + data["title"] + "\n"
+    if "message" in data:
+        text = text + data["message"] + "\n\n"
+    if "evalMatches" in data:
+        for match in data["evalMatches"]:
+            text = text + "* " + match["metric"] + ": " + str(match["value"]) + "\n"
+    data["body"] = text
+    return data