Flask: refactor email functionality into Mailer class

flask/app/config.py

@@ -41,4 +41,8 @@ class Config(object):
         "http://keycloak:8080/auth/realms/ccm/.well-known/openid-configuration",
     )
     MSTEAMS_WEBHOOK_URL = os.getenv("MSTEAMS_WEBHOOK_URL")
+    SENDGRID_API_KEY = os.getenv("SENDGRID_API_KEY")
+    SENDGRID_EMAIL_TEMPLATE_ID = os.getenv("SENDGRID_EMAIL_TEMPLATE_ID")
+    SENDGRID_TO_EMAIL = os.getenv("SENDGRID_TO_EMAIL")
+    SENDGRID_FROM_EMAIL = os.getenv("SENDGRID_FROM_EMAIL")
     # LOGIN_DISABLED = True

flask/app/email.py

@@ -1,81 +1,147 @@
 import json
 import math
-import os
 from datetime import datetime, timedelta
 from typing import Any, Dict
 
-from flask import current_app as app
+from flask import Flask
 from sendgrid import SendGridAPIClient
 from sendgrid.helpers.mail import From, Mail, SendAt, To
-
-
-# https://github.com/sendgrid/sendgrid-python
-sg = SendGridAPIClient(os.getenv("SENDGRID_API_KEY"))
-
-
-def send_email(
-    from_email: str, to_emails: str, dynamic_template_object: Dict[str, Any]
-) -> None:
-    """Sends an email based on a template stored in SendGrid
-    :param dynamic_template_object: Data for a transactional template.
-    :type dynamic_template_object: A JSON-serializable structure
-    :param from: Sender of the email. The sender's email domain needs to have been authenticated and added to SendGrid Dashboard.
-    :type from:  string
-    :param from: Email of the recipient
-    :type from:  string
-    """
-
-    emails_stats = get_daily_stats()
-
-    scheduled_time = get_send_time(emails_stats)
-
-    message = Mail()
-
-    message.to = To(to_emails)
-    message.from_email = From(from_email, "Stager Team")
-    message.send_at = SendAt(math.ceil(scheduled_time))
-    message.dynamic_template_data = dynamic_template_object
-    message.template_id = os.getenv("SENDGRID_EMAIL_TEMPLATE_ID")
-
-    try:
-        sg.send(message)
-        app.logger.debug(f"Email successfully sent from {from_email} to {to_emails}")
-    except Exception as e:
-        app.logger.error("Failed to send email...")
-        app.logger.error(e)
-
-
-def get_daily_stats():
-    today = datetime.now().strftime("%Y-%m-%d")
-    params = {
-        "aggregated_by": "day",
-        "start_date": today,
-        "end_date": today,
-        "offset": 1,
-    }
-    try:
-        response = sg.client.stats.get(query_params=params)
-        return json.loads(response.body.decode("utf-8"))
-    except Exception as e:
-        app.logger.error("Failed to get daily email stats")
-        app.logger.debug(e)
-        return []
-
-
-def get_send_time(stats):
-    limit_per_day = 100
-    send_at = datetime.now()
-
-    for stat in stats:
-
-        requests_count = sum(
-            [r.get("metrics").get("requests") for r in stat.get("stats")]
-        )
-
-        if stat.get("date") == datetime.strftime(send_at, "%Y-%m-%d"):
-            if requests_count < limit_per_day:
-                send_at = send_at + timedelta(seconds=15)
-            else:
-                send_at = send_at + timedelta(days=1, seconds=15)
-
-    return send_at.timestamp()
+from sqlalchemy.orm import joinedload
+
+from . import models
+
+
+class Mailer:
+    def __init__(self, app: Flask):
+        self.app = app
+        # https://github.com/sendgrid/sendgrid-python
+        self.sg = SendGridAPIClient(app.config["SENDGRID_API_KEY"])
+
+    def send(
+        self, from_email: str, to_emails: str, dynamic_template_object: Dict[str, Any]
+    ) -> None:
+        """Sends an email based on a template stored in SendGrid
+        :param dynamic_template_object: Data for a transactional template.
+        :type dynamic_template_object: A JSON-serializable structure
+        :param from: Sender of the email. The sender's email domain needs to have been authenticated and added to SendGrid Dashboard.
+        :type from:  string
+        :param from: Email of the recipient
+        :type from:  string
+        """
+
+        emails_stats = self._get_daily_stats()
+
+        scheduled_time = self._get_send_time(emails_stats)
+
+        message = Mail()
+
+        message.to = To(to_emails)
+        message.from_email = From(from_email, "Stager Team")
+        message.send_at = SendAt(math.ceil(scheduled_time))
+        message.dynamic_template_data = dynamic_template_object
+        message.template_id = self.app.config["SENDGRID_EMAIL_TEMPLATE_ID"]
+
+        try:
+            self.sg.send(message)
+            self.app.logger.debug(
+                f"Email successfully sent from {from_email} to {to_emails}"
+            )
+        except Exception as e:
+            self.app.logger.error("Failed to send email...")
+            self.app.logger.error(e)
+
+    def _get_daily_stats(self):
+        today = datetime.now().strftime("%Y-%m-%d")
+        params = {
+            "aggregated_by": "day",
+            "start_date": today,
+            "end_date": today,
+            "offset": 1,
+        }
+        try:
+            response = self.sg.client.stats.get(query_params=params)
+            return json.loads(response.body.decode("utf-8"))
+        except Exception as e:
+            self.app.logger.error("Failed to get daily email stats")
+            self.app.logger.debug(e)
+            return []
+
+    def _get_send_time(self, stats):
+        limit_per_day = 100
+        send_at = datetime.now()
+
+        for stat in stats:
+
+            requests_count = sum(
+                [r.get("metrics").get("requests") for r in stat.get("stats")]
+            )
+
+            if stat.get("date") == datetime.strftime(send_at, "%Y-%m-%d"):
+                if requests_count < limit_per_day:
+                    send_at = send_at + timedelta(seconds=15)
+                else:
+                    send_at = send_at + timedelta(days=1, seconds=15)
+
+        return send_at.timestamp()
+
+    def send_notification(self):
+        """
+        This is a scheduled background task. Because it runs in a separate thread,
+        it pushes an app context for itself.
+        """
+        with self.app.app_context():
+            yesterday = (datetime.now() - timedelta(1)).strftime("%Y-%m-%d")
+            analyses = (
+                models.Analysis.query.options(
+                    joinedload(models.Analysis.datasets).joinedload(
+                        models.Dataset.linked_files
+                    ),
+                    joinedload(models.Analysis.requester),
+                    joinedload(models.Analysis.datasets)
+                    .joinedload(models.Dataset.tissue_sample)
+                    .joinedload(models.TissueSample.participant)
+                    .joinedload(models.Participant.family),
+                )
+                .filter(models.Analysis.requested >= yesterday)
+                .all()
+            )
+
+            email_analyses = []
+
+            for analysis in analyses:
+                email_analyses.append(
+                    {
+                        "analysis_id": analysis.analysis_id,
+                        "requested": analysis.requested.strftime("%Y-%m-%d"),
+                        "requester": analysis.requester.username,
+                        "pipeline": analysis.kind,
+                        "priority": analysis.priority.value,
+                        "datasets": [
+                            {
+                                "dataset_id": dataset.dataset_id,
+                                "notes": dataset.notes or "",
+                                "linked_files": ", ".join(
+                                    [file.path for file in dataset.linked_files]
+                                ),
+                                "participant_codename": dataset.tissue_sample.participant.participant_codename,
+                                "participant_aliases": dataset.tissue_sample.participant.participant_aliases
+                                or "",
+                                "family_codename": dataset.tissue_sample.participant.family.family_codename,
+                                "participant_notes": dataset.tissue_sample.participant.notes
+                                or "",
+                            }
+                            for dataset in analysis.datasets
+                        ],
+                    }
+                )
+
+            if len(email_analyses) > 0:
+                self.send(
+                    to_emails=self.app.config["SENDGRID_TO_EMAIL"],
+                    from_email=self.app.config["SENDGRID_FROM_EMAIL"],
+                    dynamic_template_object={"analyses": email_analyses},
+                )
+
+            self.app.logger.debug(
+                f"{len(email_analyses)} analysis requests found... {json.dumps(email_analyses)}"
+            )

flask/app/stager.py

@@ -1,6 +1,5 @@
 import atexit
-from os import getenv
-from logging import INFO, Formatter
+from logging import Formatter
 
 from apscheduler.schedulers.base import BaseScheduler
 from apscheduler.schedulers.background import BackgroundScheduler
@@ -11,8 +10,8 @@
 from prometheus_flask_exporter import PrometheusMetrics
 from prometheus_flask_exporter.multiprocess import GunicornPrometheusMetrics
 
+from .email import Mailer
 from .login import StagerLoginManager
-from .tasks import send_email_notification
 from .utils import DateTimeEncoder
 
 
@@ -23,6 +22,7 @@ class Stager(Flask):
 
     json_encoder = DateTimeEncoder
     # Only available in master process
+    mailer: Mailer  # Only available if configured
     scheduler: BaseScheduler
 
     def __init__(self, config, db: SQLAlchemy, *args, **kwargs):
@@ -70,9 +70,20 @@ def start_scheduler(self):
         # or cumbersome, it can be separated to be started by a completely different
         # entrypoint in the same codebase and deployed as a separate container.
         self.scheduler = BackgroundScheduler()
-        if getenv("SENDGRID_API_KEY"):
+        if self.config["SENDGRID_API_KEY"]:
+            self.logger.info(
+                "Configuring with SendGrid [%s] (from: %s) (to: %s)",
+                self.config["SENDGRID_EMAIL_TEMPLATE_ID"],
+                self.config["SENDGRID_FROM_EMAIL"],
+                self.config["SENDGRID_TO_EMAIL"],
+            )
+            self.mailer = Mailer(self)
             self.scheduler.add_job(
-                send_email_notification, "cron", [self], day_of_week="mon-fri", hour="9"
+                self.mailer.send_notification,
+                "cron",
+                [self],
+                day_of_week="mon-fri",
+                hour="9",
             )
         self.scheduler.start()
         if self.env == "development":