some tests and reformating

config.yaml.exp

@@ -7,4 +7,22 @@ host: 127.0.0.1
 alert_rooms:
   - "#troy:matrix.org"
   - "#ithaca:matrix.org"
+templates:
+  "Test": |
+    {% if alert['labels']['severity'] == 'critical' and alert['status'] == 'firing' %}
+    @room<b><font color='red'>
+    {% elif alert['labels']['severity'] == 'warning' and alert['status'] == 'firing' %}
+    <b><font color='orange'>
+    {% elif alert['status'] == 'resolved' %}
+    <b><font color='green'> End of alert
+    {% else %}
+    <b><font>
+    {% endif %}
+    {{ alert['labels']['alertname'] }}: {{ alert['labels']['instance'] }} <br/>
+    </font></b>
+    {{ alert['annotations']['title'] }}<br/>
+    {{ alert['annotations']['description'] }}<br/>
+
+    But this is a custom template for Cassandre, so, here is a warning:<br/>
+    <blockquote>Beware of greeks bearing gifts</blockquote>
 ...

setup.cfg

@@ -12,6 +12,7 @@ packages = kassandra
 python_requires = >=3.9.2
 package_dir = =src
 install_requires =
+    Jinja2>=3.0.2
     PyYAML>=5.4.1
 	matrix-bot @ git+https://gitea.auro.re/histausse/matrix-bot.git
 

src/kassandra/__main__.py

@@ -21,7 +21,8 @@ async def __main():
     )
     format_corout = format_alerts(
         alert_queue,
-        message_queue
+        message_queue,
+        config
     )
     webhook_corout = run_webhook(
         alert_queue,

src/kassandra/config.py

@@ -21,6 +21,8 @@ class Config:
     tls_crt: Optional[str] = None
     tls_key: Optional[str] = None
     ca_crt: Optional[str] = None
+    default_template: Optional[str] = None
+    templates: dict[str, str] = dataclasses.field(default_factory=dict)
 
     def check_integrity(self)->bool:
         """ Check the integrity of the config.

src/kassandra/format.py

@@ -5,37 +5,102 @@ Format the alert message.
 import asyncio
 import dataclasses
 import json
+from collections import defaultdict
 from typing import (
     Any,
     NoReturn,
     Optional
 )
+from jinja2 import BaseLoader, Environment, Template
+from .config import Config
 
 @dataclasses.dataclass
 class Message:
     body: str
     formated_body: Optional[str]
 
+DEFAULT_TEMPLATE_RAW: str = (
+    "{% if alert['labels']['severity'] == 'critical' and alert['status'] == 'firing' %}"
+    "@room<b><font color='red'>"
+    "{% elif alert['labels']['severity'] == 'warning' and alert['status'] == 'firing' %}"
+    "<b><font color='orange'>"
+    "{% elif alert['status'] == 'resolved' %}"
+    "<b><font color='green'> End of alert "
+    "{% else %}"
+    "<b><font>"
+    "{% endif %}"
+    "{{ alert['labels']['alertname'] }}: {{ alert['labels']['instance'] }} <br/>"
+    "</font></b>"
+    "{{ alert['annotations']['title'] }}<br/>"
+    "{{ alert['annotations']['description'] }}<br/>"
+)
+
+def load_templates(
+    config: Config
+)->defaultdict[str, Template]:
+    """
+        Create a dict mapping alert names to the template to use from
+        the config, with a default template either from the config file
+        or the default DEFAULT_TEMPLATE_RAW.
+    """
+    if config.default_template is None:
+        default_template = Environment(
+            loader=BaseLoader
+        ).from_string(
+           DEFAULT_TEMPLATE_RAW
+        )
+    else:
+        default_template = Environment(
+            loader=BaseLoader
+        ).from_string(
+            config.default_template
+        )
+    templates = defaultdict(lambda: default_template)
+    for alert_name in config.templates:
+        templates[alert_name] = Environment(
+            loader=BaseLoader
+        ).from_string(
+            config.templates[alert_name]
+        )
+    return templates
+
+
 def format_alert(
-    alert: dict[str, Any]
-)->Message:
+    alert_json: dict[str, Any],
+    templates: defaultdict[str, Template]
+)->list[Message]:
     """
         Format an alert in json format to a nice string.
     """
-    body = json.dumps(alert, indent=4)
-    formated_body = f"<pre><code>{body}</code></pre>\n"
-    return Message(body, formated_body)
+    messages = []
+    for alert in alert_json['alerts']:
+        template = templates[alert['labels']['alertname']]
+        formated_body = template.render(alert=alert)
+        body = "alert {status}:\n{alertname} on {instance}".format(
+            status=alert['status'],
+            alertname=alert['labels']['alertname'],
+            instance=alert['labels']['instance']
+        )
+        if '@room' in formated_body:
+            body = '@room ' + body
+            formated_body = formated_body.replace('@room', '')
+        messages.append(Message(body, formated_body))
+    return messages
 
 async def format_alerts(
     alert_queue: asyncio.Queue[dict[str,Any]],
-    message_queue: asyncio.Queue[Message]
+    message_queue: asyncio.Queue[Message],
+    config: Config
 )->NoReturn:
     """
         Read alerts from alert_queue, format them, and put them in message_queue.
     """
+    templates = load_templates(config)
+
     while True:
         alert = await alert_queue.get()
-        message = format_alert(alert)
-        await message_queue.put(message)
+        messages = format_alert(alert, templates)
+        for message in messages:
+            await message_queue.put(message)
         alert_queue.task_done()