✨ — Implement mail alerts. Fix #15

argos/schemas/config.py

@@ -4,7 +4,7 @@ For database models, see argos.server.models.
 """
 from typing import Dict, List, Literal, Optional, Tuple
 
-from pydantic import BaseModel, ConfigDict, HttpUrl, field_validator
+from pydantic import BaseModel, ConfigDict, HttpUrl, StrictBool, EmailStr, PositiveInt, field_validator
 from pydantic.functional_validators import BeforeValidator
 from typing_extensions import Annotated
 
@@ -93,6 +93,23 @@ class Service(BaseModel):
     secrets: List[str]
 
 
+class MailAuth(BaseModel):
+    """Mail authentication configuration"""
+    login: str
+    password: str
+
+
+class Mail(BaseModel):
+    """Mail configuration"""
+    mailfrom: EmailStr
+    host: Optional[str] = None
+    port: Optional[PositiveInt] = None
+    ssl: Optional[StrictBool] = None
+    starttls: Optional[StrictBool] = None
+    auth: Optional[MailAuth] = None
+    addresses: List[EmailStr]
+
+
 class Alert(BaseModel):
     """List of way to handle alerts, by severity"""
 
@@ -107,6 +124,7 @@ class General(BaseModel):
 
     frequency: int
     alerts: Alert
+    mail: Optional[Mail] = None
 
     @field_validator("frequency", mode="before")
     def parse_frequency(cls, value):

argos/server/alerting.py

@@ -1,3 +1,8 @@
+import ssl
+import smtplib
+
+from urllib.parse import urlparse
+
 from argos.logging import logger
 
 # XXX Implement mail alerts https://framagit.org/framasoft/framaspace/argos/-/issues/15
@@ -7,3 +12,69 @@ def handle_alert(config, result, task, severity):
     """Dispatch alert through configured alert channels"""
     msg = f"task={task.id}, status={result.status}, {severity=}"
     logger.error("Alerting stub: %s", msg)
+
+    if 'mail' in config and 'addresses' in config['mail']:
+        logger.debug('Notify of failure by mail')
+
+        msg = f"""\
+Subject: Argos {urlparse(task.url).netloc} status {severity}
+
+URL:    {task.url}
+Check:  {task.check}
+Status: {severity}
+Time:   {result.submitted_at}
+"""
+        notify_by_mail(msg=msg, config=config['mail'])
+
+
+def notify_by_mail(msg: str, config: dict) -> None:
+    """Notify by mail
+
+    Keyword argument:
+    msg    -- string, the mail to send (including subject)
+    config -- dict, configuration of mail system
+    """
+    if 'mailfrom' not in config:
+        logger.error('No "mailfrom" address in mail config. '
+                     'Not sending mail.')
+        return None
+    if 'host' not in config:
+        config['host'] = '127.0.0.1'
+    if 'port' not in config:
+        config['port'] = 25
+    if 'ssl' not in config:
+        config['ssl'] = False
+    if 'starttls' not in config:
+        config['starttls'] = False
+    if config['ssl']:
+        logger.debug('Mail notification: SSL')
+        context = ssl.create_default_context()
+        smtp = smtplib.SMTP_SSL(host=config['host'],
+                                port=config['port'],
+                                context=context)
+    else:
+        smtp = smtplib.SMTP(host=config['host'],  # type: ignore
+                            port=config['port'])
+        if config['starttls']:
+            logger.debug('Mail notification: STARTTLS')
+            context = ssl.create_default_context()
+            smtp.starttls(context=context)
+
+    if 'auth' in config:
+        if 'login' not in config['auth'] \
+           or 'password' not in config['auth']:
+            logger.warning('Mail credentials are incomplete. '
+                           'No mail authentication can be done. '
+                           'Not sending mail.')
+            return None
+
+        logger.debug('Mail notification: authentification')
+        smtp.login(config['auth']['login'],
+                   config['auth']['password'])
+
+    for address in config['addresses']:
+        logger.debug('Sending mail to %s', address)
+        logger.debug(msg)
+        smtp.sendmail(config['from'], address, msg)
+
+    return None

argos/server/routes/api.py

@@ -44,18 +44,21 @@ async def create_results(
     agent_id = agent_id or request.client.host
     db_results = []
     for agent_result in results:
-        result = await queries.create_result(db, agent_result, agent_id)
         # XXX Maybe offload this to a queue.
         # XXX Get all the tasks at once, to limit the queries on the db
         task = await queries.get_task(db, agent_result.task_id)
         if not task:
             logger.error("Unable to find task %i", agent_result.task_id)
         else:
+            last_severity = task.severity
+            result = await queries.create_result(db, agent_result, agent_id)
             check = task.get_check()
             status, severity = await check.finalize(config, result, **result.context)
             result.set_status(status, severity)
             task.set_times_and_deselect()
 
+            # Don’t create an alert if the severity has not changed
+            if last_severity != severity:
                 handle_alert(config, result, task, severity)
 
         db_results.append(result)

pyproject.toml

@@ -20,7 +20,7 @@ dependencies = [
   "click>=8.1,<9",
   "fastapi>=0.103,<0.104",
   "httpx>=0.25,<1",
-  "pydantic>=2.4,<3",
+  "pydantic[email]>=2.4,<3",
   "pyyaml>=6.0,<7",
   "pyyaml-include>=1.3,<2",
   "sqlalchemy[asyncio]>=2.0,<3",