web: add smtp-based email delivery

email.py stolen from ldapweb

web/config.py

@@ -24,6 +24,10 @@ LDAP_USER_BASE = env.str("LDAP_USER_BASE", "ou=People,dc=hackerspace,dc=pl")
 LDAP_GROUP_FILTER = env.str("LDAP_GROUP_FILTER", "(objectClass=groupOfUniqueNames)")
 LDAP_GROUP_BASE = env.str("LDAP_GROUP_BASE", "ou=Group,dc=hackerspace,dc=pl")
 
+SMTP_SERVER = env.str("SMTP_SERVER", "mail.hackerspace.pl")
+SMTP_USER = env.str("SMTP_USER", "kasownik")
+SMTP_PASSWORD = env.str("SMTP_PASSWORD", "changeme")
+
 CACHE_TYPE = env.str("CACHE_TYPE", "null")
 CACHE_NO_NULL_WARNING = True
 

web/webapp/admin.py

@@ -15,7 +15,7 @@ from flask import (
     current_app,
 )
 from flask_login import login_required
-from webapp import forms, db, models, admin_required
+from webapp import forms, db, models, admin_required, email
 
 from . import directory
 from . import logic
@@ -315,24 +315,19 @@ def sendspam():
             if not content.strip():
                 continue
 
-            msg = MIMEText(content, "plain", "utf-8")
-            msg["From"] = "Kasownik Hackerspace'owy <kasownik@hackerspace.pl>"
-            msg["Subject"] = "Stan składek na dzień %s" % now.strftime("%d/%m/%Y")
-            msg["To"] = member.get_contact_email()
-            spam.append(msg)
+            recipient_email = member.get_contact_email()
+            spam.append((recipient_email, content))
 
         if form.dry_run.data:
             readable = [
-                msg.as_string().split("\n\n")[0]
-                + "\n\n"
-                + msg.get_payload(decode=True).decode("utf-8")
-                for msg in spam
+                f"To: {recipient_email}\n\n{content}"
+                for recipient_email, content in spam
             ]
             return Response("\n====\n".join(readable), mimetype="text/plain")
 
-        for msg in spam:
-            p = Popen(["/usr/sbin/sendmail", "-t"], stdin=PIPE)
-            p.communicate(msg.as_bytes())
+        smpt_conn = email.get_connection()
+        for recipient_email, content in spam:
+            email.send_email(smpt_conn, "Reminder about your Warsaw Hackerspace membership fees", content, recipient_email)
 
         flash("%d messages sent!" % len(spam))
         return redirect(url_for(".index"))

web/webapp/email.py

@@ -0,0 +1,46 @@
+import smtplib
+from email.message import EmailMessage
+import flask
+import datetime
+from typing import Optional
+
+from webapp import app
+
+cached_connection: Optional[smtplib.SMTP] = None
+
+
+def test_connection_open(conn: smtplib.SMTP) -> bool:
+    try:
+        status = conn.noop()[0]
+    except:
+        status = -1
+    return True if status == 250 else False
+
+
+def create_connection() -> smtplib.SMTP:
+    print("Connecting to SMTP...")
+    conn = smtplib.SMTP_SSL(app.config["SMTP_SERVER"])
+    conn.login(app.config["SMTP_USER"], app.config["SMTP_PASSWORD"])
+    return conn
+
+
+def get_connection() -> smtplib.SMTP:
+    global cached_connection
+    if cached_connection is not None and test_connection_open(cached_connection):
+        return cached_connection
+
+    cached_connection = create_connection()
+    return cached_connection
+
+
+def send_email(
+    conn: smtplib.SMTP, subject: str, body: str, recipient_emails: str
+) -> None:
+    msg = EmailMessage()
+    msg.set_content(body)
+    msg["Subject"] = subject
+
+    msg["From"] = f"Warsaw Hackerspace Kasownik <kasownik@hackerspace.pl>"
+    msg["To"] = recipient_emails
+
+    conn.send_message(msg)