Update to Flask 2 and matrix-nio

Use asynchronously running code.
Rewrite error handling and all api interactions.
Add config.yml.example and more configuration options.
Improve README.md.
Update licenses in all files.

.idea/misc.xml

@@ -3,7 +3,7 @@
   <component name="JavaScriptSettings">
     <option name="languageLevel" value="ES6" />
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.8 (webhook-matrix-notifier)" project-jdk-type="Python SDK" />
+  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.9 (webhook-matrix-notifier)" project-jdk-type="Python SDK" />
   <component name="PythonCompatibilityInspectionAdvertiser">
     <option name="version" value="3" />
   </component>

.idea/webhook-matrix-notifier.iml

@@ -4,7 +4,7 @@
     <content url="file://$MODULE_DIR$">
       <excludeFolder url="file://$MODULE_DIR$/venv" />
     </content>
-    <orderEntry type="inheritedJdk" />
+    <orderEntry type="jdk" jdkName="Python 3.9 (webhook-matrix-notifier)" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>

Dockerfile

@@ -1,6 +1,6 @@
 FROM alpine
 
-RUN apk add --no-cache uwsgi-python3 python3
+RUN apk add --no-cache uwsgi-python3 python3 py3-yaml py3-flask py3-matrix-nio
 
 # partly from https://hub.docker.com/_/python?tab=description#create-a-dockerfile-in-your-python-app-project
 WORKDIR /usr/src/wmn

LICENSE

@@ -1,4 +1,4 @@
-Copyright 2019 Benedikt Ziemons
+Copyright 2019-2021 Benedikt Ziemons
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in

README.md

@@ -1,14 +1,31 @@
 # Webhook Matrix Notifier
 
-Takes notifications via webhook, checks a secret and notifies a
+Takes notifications via webhook, checks a secret and notifies a [Matrix](https://matrix.org) channel.
-[Matrix](https://matrix.org) channel. Listens to HTTP only. Should be used
+Listens to HTTP only. Should be used behind a reverse-proxy with HTTPS.
-behind a reverse-proxy with HTTPS.
 
-# Testing the Hook locally
+An example configuration is at `config.yml.example` and the program always reads the configuration file `config.yml`.
-- Start the webserver locally by `env FLASK_APP=wmn.py flask run`
+
-  - Or have your IDE do it for you
+
-- Send a POST request using curl `curl -i -X POST "localhost:5000/matrix?channel=%21yhEUnvhAZZFKRStdXb%3Amatrix.org" -H "X-Gitlab-Event: Push Hook" -H "X-Gitlab-Token: ..." -H "Content-Type: application/json" --data-binary @./testrequest_gitlab.json`
+## Testing the Hook locally
-  - The part after `channel=` is the room ID which can retrieved from Matrix channels you are part of
+
-  - `%21` escapes ! in URI
+First, start the webserver locally by `env FLASK_APP=wmn.py flask run` or have your IDE start it for you. \
-  - `%3A` escapes : in URI
+Then, send a POST request using curl.
-  - The `X-Gitlab-Token` must correspond to the one provided in `config.yaml`
+
+### GitLab
+
+```
+export CHANNEL_ENC=`python3 -c 'from urllib.parse import quote_plus; print(quote_plus("#channel:matrix.org"))'`
+curl -i -X POST "http://localhost:5000/matrix?channel=${CHANNEL_ENC}" -H "X-Gitlab-Event: Push Hook" -H "X-Gitlab-Token: 123" -H "Content-Type: application/json" --data-binary @./testrequest_gitlab.json
+```
+
+The `X-Gitlab-Token` must correspond to the secret provided in `config.yml`
+
+### Prometheus
+
+```
+export CHANNEL_ENC=`python3 -c 'from urllib.parse import quote_plus; print(quote_plus("#channel:matrix.org"))'`
+export WMN_SECRET=`python3 -c 'from urllib.parse import quote_plus; print(quote_plus("123"))'`
+curl -i -X POST "http://localhost:5000/matrix?type=prometheus&secret=${WMN_SECRET}&channel=${CHANNEL_ENC}" -H "Content-Type: application/json" --data-binary @./testrequest_prometheus.json
+```
+
+The secret must be passed as a URI parameter here.

config.yml.example

@@ -0,0 +1,15 @@
+# secret for other services to interact with this webhook
+secret: "…"
+
+matrix:
+  server: https://matrix.org
+  username: …
+
+  # optional
+  store_path: …
+  device_name: …
+  device_id: …  # will be filled automatically otherwise
+
+  # use password or token
+  password: "…"
+  token: …

notify.py

@@ -1,32 +1,39 @@
 #!/usr/bin/env python3
+# Copyright 2019-2021 Benedikt Ziemons
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy of
+# this software and associated documentation files (the "Software"), to deal in
+# the Software without restriction, including without limitation the rights to
+# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+# the Software, and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 import argparse
+import asyncio
 import re
 import sys
 
+import nio
 import yaml
-from matrix_client.client import MatrixClient
+
+from wmn import client_login, resolve_room, send_message
 
 # Not going to care for specifics like the underscore.
 # Generally match !anything:example.com with unicode support.
 room_pattern = re.compile(r"^!\w+:[\w\-.]+$")
 
 
-def send_message(cfg, args):
+async def main():
-    client = MatrixClient(cfg["matrix"]["server"])
-    client.login(username=cfg["matrix"]["username"], password=cfg["matrix"]["password"])
-    room = client.join_room(room_id_or_alias=args.channel)
-
-    if "html" in args:
-        body = None if len(args.text) == 0 else str(args.text)
-        room.send_html(html=args.html, body=body, msgtype=args.type)
-    else:
-        room.client.api.send_message(
-            room_id=room.room_id, text_content=args.text, msgtype=args.type
-        )
-
-
-def main():
     """
     config.yml Example:
 
@@ -60,9 +67,23 @@ def main():
         print("ERROR: Couldn't parse channel as a matrix channel", file=sys.stderr)
         sys.exit(1)
 
-    send_message(cfg, args)
+    client = await client_login(cfg)
-    print("Message sent.", file=sys.stderr)
+    try:
+        room_id = await resolve_room(client=client, room=args.channel)
+        response = await client.join(room_id=room_id)
+        if isinstance(response, nio.ErrorResponse):
+            raise response
+
+        if "html" in args:
+            response = await send_message(client=client, room_id=room_id, text=(args.text or ""), msgtype=args.type, html=args.html)
+        else:
+            response = await send_message(client=client, room_id=room_id, text=args.text, msgtype=args.type)
+        print("Message sent.", file=sys.stderr, flush=True)
+    finally:
+        await client.close()
+    print(response.event_id)
 
 
 if __name__ == "__main__":
-    main()
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(main())

requirements.txt

@@ -1,3 +1,3 @@
 PyYAML>=5.1,<6
-Flask>=1.1.1,<2
+flask[async]>=2.0.0,<3
-matrix-client>=0.3.2,<0.4
+matrix-nio[e2e]>=0.18.0,<1

wmn.py

@@ -1,14 +1,37 @@
+# Copyright 2019-2021 Benedikt Ziemons
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy of
+# this software and associated documentation files (the "Software"), to deal in
+# the Software without restriction, including without limitation the rights to
+# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+# the Software, and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
 import json
 import re
 import sys
 import traceback
-import typing
 from datetime import datetime
+from typing import Tuple, Optional, Dict, Any
 
+import nio
 import yaml
 from flask import Flask, request, abort
-from matrix_client.client import MatrixClient
+from werkzeug.datastructures import MultiDict
-from matrix_client.errors import MatrixRequestError
+
+Cfg = Dict[str, Any]
+ErrorResponse = Tuple[str, int]
+RequestArgs = MultiDict[str, str]
 
 app = Flask(__name__)
 application = app
@@ -17,28 +40,25 @@ application = app
 # Generally match room alias or id [!#]anything:example.com with unicode support.
 room_pattern = re.compile(r"^[!#]\w+:[\w\-.]+$")
 
-# prometheus has to many sub-second digits in their timestamp,
+# older prometheus/alertmanager versions send too many sub-second digits in their timestamp,
 # so we get rid of nanoseconds here
 promtime_to_isotime_pattern = re.compile(
     r"([0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2})(\.[0-9]{6})?(?:[0-9]{3})?(Z|[+-][0-9]{2}:[0-9]{2})"
 )
 
-"""
-config.yml Example:
 
-secret: "..."
+def load_configuration() -> Cfg:
-matrix:
+    with open("config.yml", "r") as ymlfile:
-  server: https://matrix.org
+        return yaml.safe_load(ymlfile)
-  username: ...
-  password: "..."
-"""
-with open("config.yml", "r") as ymlfile:
-    cfg = yaml.safe_load(ymlfile)
 
 
-def check_token(header_field: str):
+def save_configuration(configuration: Cfg):
-    token = request.headers.get(header_field)
+    with open("config.yml", "w") as ymlfile:
-    if token != cfg["secret"]:
+        yaml.safe_dump(configuration, ymlfile)
+
+
+def check_token(configuration: Cfg, token: str):
+    if token != configuration["secret"]:
         print(
             "check_token failed, because token did not match",
             file=sys.stderr,
@@ -47,15 +67,39 @@ def check_token(header_field: str):
         abort(401)
 
 
-def get_a_room():
+async def resolve_room(client: nio.AsyncClient, room: str) -> str:
-    if "channel" not in request.args:
+    """Takes a room alias or room id and always returns a resolved room id."""
+
+    if room.startswith("#"):
+        response = await client.room_resolve_alias(room_alias=room)
+        if isinstance(response, nio.ErrorResponse):
+            abort(app.make_response(matrix_error(response)))
+        return response.room_id
+    elif room.startswith("!"):
+        return room
+    else:
+        raise RuntimeError(f"Room {room} could not be resolved")
+
+
+async def get_a_room(client: nio.AsyncClient, request_args: RequestArgs) -> str:
+    """Takes a nio.AsyncClient and the request args to return a room id."""
+
+    if "channel" not in request_args:
         print(
             "get_a_room failed, because channel was not in request args",
             file=sys.stderr,
             flush=True,
         )
         abort(400)
-    room = request.args.get("channel")
+    room = request_args.get("channel")
+    if not room:
+        print(
+            "get_a_room failed, because channel was empty",
+            file=sys.stderr,
+            flush=True,
+        )
+        abort(400)
+
     # sanitize input
     if room_pattern.fullmatch(room) is None:
         print(
@@ -67,13 +111,14 @@ def get_a_room():
             flush=True,
         )
         abort(400)
-    return room
+
+    return await resolve_room(client=client, room=room)
 
 
-def get_msg_type():
+def get_msg_type(request_args: RequestArgs):
-    if "msgtype" not in request.args:
+    if "msgtype" not in request_args:
         return "m.notice"
-    msgtype = request.args.get("msgtype")
+    msgtype = request_args.get("msgtype")
     if msgtype in ["m.text", "m.notice"]:
         return msgtype
     else:
@@ -102,33 +147,83 @@ def shorten(string: str, max_len: int = 80, appendix: str = "..."):
         return string
 
 
-def matrix_error(error: MatrixRequestError):
+async def client_login(configuration: Cfg) -> nio.AsyncClient:
-    print("matrix_error was called with", error, file=sys.stderr)
+    client = nio.AsyncClient(
-    traceback.print_exception(MatrixRequestError, error, error.__traceback__)
+        homeserver=configuration["matrix"].get("server"),
-    print(file=sys.stderr, flush=True)
+        user=configuration["matrix"].get("username", ""),
+        device_id=configuration["matrix"].get("device_id", ""),
+        store_path=configuration["matrix"].get("store_path", ""),
+    )
+    response = await client.login(
+        password=configuration["matrix"].get("password", None),
+        device_name=configuration["matrix"].get("device_name", ""),
+        token=configuration["matrix"].get("token", None),
+    )
+    if isinstance(response, nio.ErrorResponse):
+        raise response
+
+    if "device_id" not in configuration["matrix"]:
+        configuration["matrix"]["device_id"] = response.device_id
+        save_configuration(configuration)
+    return client
+
+
+async def send_message(
+    client: nio.AsyncClient,
+    room_id: str,
+    text: str,
+    msgtype: str = "m.text",
+    html: Optional[str] = None
+) -> nio.RoomSendResponse:
+    content = {
+        "body": text,
+        "msgtype": msgtype,
+    }
+    if html is not None:
+        content["format"] = "org.matrix.custom.html"
+        content["formatted_body"] = html
+    response = await client.room_send(
+        room_id=room_id,
+        message_type="m.room.message",
+        content=content,
+        ignore_unverified_devices=True,
+    )
+    if isinstance(response, nio.ErrorResponse):
+        raise response
+    return response
+
+
+def matrix_error(error: nio.ErrorResponse) -> ErrorResponse:
+    print("matrix_error was called with", error, file=sys.stderr, flush=True)
     # see Flask.make_response, this will be interpreted as (body, status)
-    return f"Error from Matrix: {error.content}", error.code
+    if error.status_code:
+        status = int(error.status_code)
+    else:
+        status = 500
+    return f"Error from Matrix: {error.message}", status
 
 
-def process_gitlab_request():
+async def process_gitlab_request():
-    check_token("X-Gitlab-Token")
+    cfg = load_configuration()
-    msgtype = get_msg_type()
+    check_token(configuration=cfg, token=request.headers.get("X-Gitlab-Token"))
-    room = get_a_room()
     gitlab_event = request.headers.get("X-Gitlab-Event")
 
+    try:
+        client = await client_login(cfg)
+    except nio.ErrorResponse as response:
+        return matrix_error(response)
+
+    try:
+        room_id = await get_a_room(client, request.args)
+        msgtype = get_msg_type(request_args=request.args)
+
         if gitlab_event == "Push Hook":
             if request.json["total_commits_count"] < 1:
                 return "", 204
 
-        try:
+            response = await client.join(room_id=room_id)
-            client = MatrixClient(cfg["matrix"]["server"])
+            if isinstance(response, nio.ErrorResponse):
-            client.login(
+                return matrix_error(response)
-                username=cfg["matrix"]["username"], password=cfg["matrix"]["password"]
-            )
-
-            room = client.join_room(room_id_or_alias=room)
-        except MatrixRequestError as e:
-            return matrix_error(e)
 
             def sort_commits_by_time(commits):
                 return sorted(commits, key=lambda commit: commit["timestamp"])
@@ -159,37 +254,46 @@ def process_gitlab_request():
             text_commits = "\n".join(
                 (f"- [{msg}]({url})" for (msg, url) in commit_messages)
             )
-        try:
+
-            room.send_html(
+            response = await client.room_send(
-                f"<strong>{username} pushed {len(commit_messages)} commits{to_str}</strong><br>\n"
+                room_id=room_id,
+                message_type="m.room.message",
+                content={
+                    "msgtype": msgtype,
+                    "format": "org.matrix.custom.html",
+                    "formatted_body": f"<strong>{username} pushed {len(commit_messages)} commits{to_str}</strong><br>\n"
                     f"<ul>\n{html_commits}\n</ul>\n",
-                body=f"{username} pushed {len(commit_messages)} commits{to_str}\n{text_commits}\n",
+                    "body": f"{username} pushed {len(commit_messages)} commits{to_str}\n{text_commits}\n",
-                msgtype=msgtype,
+                },
+                ignore_unverified_devices=True,
             )
-        except MatrixRequestError as e:
+            if isinstance(response, nio.ErrorResponse):
-            return matrix_error(e)
+                return matrix_error(response)
+
+    except nio.ErrorResponse as response:
+        abort(app.make_response(matrix_error(response)))
+    finally:
+        await client.close()
 
     # see Flask.make_response, this is interpreted as (body, status)
     return "", 204
 
 
-def process_jenkins_request():
+async def process_jenkins_request():
-    check_token("X-Jenkins-Token")
+    cfg = load_configuration()
-    msgtype = get_msg_type()
+    check_token(configuration=cfg, token=request.headers.get("X-Jenkins-Token"))
-    room = get_a_room()
+    msgtype = get_msg_type(request_args=request.args)
+
+    try:
+        client = await client_login(cfg)
+    except nio.ErrorResponse as response:
+        return matrix_error(response)
+
+    try:
+        room_id = await get_a_room(client, request.args)
         jenkins_event = request.headers.get("X-Jenkins-Event")
 
         if jenkins_event == "Post Build Hook":
-        try:
-            client = MatrixClient(cfg["matrix"]["server"])
-            client.login(
-                username=cfg["matrix"]["username"], password=cfg["matrix"]["password"]
-            )
-
-            room = client.join_room(room_id_or_alias=room)
-        except MatrixRequestError as e:
-            return matrix_error(e)
-
             project_url = request.json["githubProjectUrl"]
 
             def extract_change_message(change):
@@ -223,67 +327,60 @@ def process_jenkins_request():
             else:
                 text_change_messages, html_change_messages = (), ()  # it's an owl!
 
-        newline = "\n"
+            newline = "\n"  # expressions inside f-strings cannot contain backslashes...
-        try:
+            html_changes = (
-            room.send_html(
-                f"<p><strong>Build {build_name} on project {project_name} complete: "
-                f'<font color="{result_color}">{result_type}</font></strong>, '
-                f"{len(changes)} commits</p>\n"
-                ""
-                + (
                 f"<ul>\n{newline.join(html_change_messages)}\n</ul>\n"
                 if len(html_change_messages) > 0
                 else ""
-                ),
+            )
-                body=f"**Build {build_name} on project {project_name} complete: {result_type}**, "
+            text_changes = (
-                f"{len(changes)} commits\n"
-                ""
-                + (
                 f"{newline.join(text_change_messages)}\n"
                 if len(text_change_messages) > 0
                 else ""
+            )
+            await send_message(
+                client=client,
+                room_id=room_id,
+                text=(
+                    f"**Build {build_name} on project {project_name} complete: {result_type}**, "
+                    f"{len(changes)} commits\n"
+                    f"{text_changes}"
                 ),
                 msgtype=msgtype,
+                html=(
+                    f"<p><strong>Build {build_name} on project {project_name} complete: "
+                    f'<font color="{result_color}">{result_type}</font></strong>, '
+                    f"{len(changes)} commits</p>\n"
+                    f"{html_changes}"
+                ),
             )
-        except MatrixRequestError as e:
+
-            return matrix_error(e)
+    except nio.ErrorResponse as response:
+        abort(app.make_response(matrix_error(response)))
+    finally:
+        await client.close()
 
     # see Flask.make_response, this is interpreted as (body, status)
     return "", 204
 
 
-def process_prometheus_request():
+async def process_prometheus_request():
-    secret = request.args.get("secret")
-    if secret != cfg["secret"]:
-        print(
-            "check_token failed, because token did not match",
-            file=sys.stderr,
-            flush=True,
-        )
-        abort(401)
-
-    msgtype = get_msg_type()
-    room = get_a_room()
-
-    if not request.json:
-        abort(400)
-
     # written for version 4 of the alertmanager webhook JSON
     # https://prometheus.io/docs/alerting/configuration/#webhook_config
 
-    def color_status_html(status: str, text: typing.Optional[str] = None):
+    def color_status_html(status: str, text: Optional[str] = None):
         _status_colors = {"resolved": "34A91D", "firing": "EF2929"}
         if text is None:
             text = status
         return color_format_html(_status_colors.get(status, "FFFFFF"), text)
 
-    def color_severity_html(severity: str, text: typing.Optional[str] = None):
+    def color_severity_html(severity: str, text: Optional[str] = None):
         _severity_colors = {"warning": "EFAC29", "critical": "EF2929"}
         if text is None:
             text = severity
         return color_format_html(_severity_colors.get(severity, "FFFFFF"), text)
 
-    def parse_promtime(date_string):
+    def parse_promtime(date_string) -> datetime:
         match = promtime_to_isotime_pattern.match(date_string)
         if match is None:
             # weirdly enough, they switched to ISO primetime
@@ -320,9 +417,7 @@ def process_prometheus_request():
 
         return title, html_title
 
-    def extract_alert_message(
+    def extract_alert_message(alert: Dict[str, Any]) -> Tuple[str, str]:
-        alert: typing.Dict[str, typing.Any]
-    ) -> typing.Tuple[str, str]:
         """Takes the alert object and returns (text, html) as a string tuple."""
 
         labels = alert.get("labels", {})
@@ -367,40 +462,56 @@ def process_prometheus_request():
             html_message,
         )
 
-    try:
+    cfg = load_configuration()
-        client = MatrixClient(cfg["matrix"]["server"])
+    secret = request.args.get("secret")
-        client.login(
+    if secret != cfg["secret"]:
-            username=cfg["matrix"]["username"], password=cfg["matrix"]["password"]
+        print(
+            "check_token failed, because token did not match",
+            file=sys.stderr,
+            flush=True,
         )
-        room = client.join_room(room_id_or_alias=room)
+        abort(401)
+
     try:
-            for body, html in map(
+        client = await client_login(cfg)
-                extract_alert_message, request.json.get("alerts", [])
+    except nio.ErrorResponse as response:
-            ):
+        return matrix_error(response)
-                if html and body:
+
-                    room.send_html(html=html, body=body, msgtype=msgtype)
+    try:
-                elif body:
+        msgtype = get_msg_type(request_args=request.args)
-                    room.send_text(body)
+        room_id = await get_a_room(client=client, request_args=request.args)
+
+        if not request.json:
+            abort(400)
+
+        try:
+            for text, html in map(extract_alert_message, request.json.get("alerts", [])):
+                if html and text:
+                    await send_message(client=client, room_id=room_id, text=text, msgtype=msgtype, html=html)
+                elif text:
+                    await send_message(client=client, room_id=room_id, text=text, msgtype=msgtype)
         except (LookupError, ValueError, TypeError):
-            room.send_text("Error parsing data in prometheus request")
+            await send_message(client=client, room_id=room_id, text="Error parsing data in prometheus request")
             print("Error parsing JSON and forming message:", file=sys.stderr)
             traceback.print_exc()
             print(file=sys.stderr, flush=True)
             return "Error parsing JSON and forming message", 500
-    except MatrixRequestError as e:
+    except nio.ErrorResponse as response:
-        return matrix_error(e)
+        abort(app.make_response(matrix_error(response)))
+    finally:
+        await client.close()
 
-    # see Flask.make_response, this is interpreted as (body, status)
+    # see Flask.make_response, this is interpreted as (text, status)
     return "", 204
 
 
-@app.route("/matrix", methods=("POST",))
+@app.post("/matrix")
-def notify():
+async def notify():
     if "X-Gitlab-Token" in request.headers:
-        return process_gitlab_request()
+        return await process_gitlab_request()
     elif "X-Jenkins-Token" in request.headers:
-        return process_jenkins_request()
+        return await process_jenkins_request()
     elif "type" in request.args and request.args.get("type") == "prometheus":
-        return process_prometheus_request()
+        return await process_prometheus_request()
     else:
         return "Cannot determine the request's webhook cause", 400