Add base64 encoded attachments to mails (#61)

invenio_mail/config.py

@@ -16,3 +16,6 @@
 
 MAIL_DEFAULT_REPLY_TO = None
 """Reply to mail address for e-mails."""
+
+MAX_ATTACHMENT_SIZE = 1000000
+"""Max size of an attachment in bytes."""

invenio_mail/errors.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of Invenio.
+# Copyright (C) 2023      University of Münster.
+#
+# Invenio is free software; you can redistribute it and/or modify it
+# under the terms of the MIT License; see LICENSE file for more details.
+
+"""Errors and exceptions for mail module."""
+
+
+class AttachmentOversizeException(Exception):
+    """Size of attachment is too big exception."""

invenio_mail/ext.py

@@ -81,3 +81,5 @@ def init_config(app):
         for k in dir(config):
             if k.startswith("MAIL_"):
                 app.config.setdefault(k, getattr(config, k))
+            if k.startswith("MAX_"):
+                app.config.setdefault(k, getattr(config, k))

invenio_mail/tasks.py

@@ -2,18 +2,33 @@
 #
 # This file is part of Invenio.
 # Copyright (C) 2015-2018 CERN.
+# Copyright (C) 2023      University of Münster.
 #
 # Invenio is free software; you can redistribute it and/or modify it
 # under the terms of the MIT License; see LICENSE file for more details.
 
 """Background tasks for mail module."""
-
 from __future__ import absolute_import, print_function
 
+from base64 import b64decode
+
 from celery import shared_task
 from flask import current_app
 from flask_mail import Message
 
+from .errors import AttachmentOversizeException
+
+
+def send_email_with_attachments(data, attachments):
+    """Celery task for sending mails with attachments."""
+    for attachment in attachments["attachments"]:
+        if len(attachment["base64"]) > current_app.config["MAX_ATTACHMENT_SIZE"]:
+            raise AttachmentOversizeException
+
+    return _send_email_with_attachments.apply_async(
+        kwargs={"data": data, "attachments": attachments}
+    )
+
 
 @shared_task
 def send_email(data):
@@ -27,7 +42,31 @@ def send_email(data):
        `custom serializer <http://docs.celeryproject.org/en/latest/
        userguide/calling.html#serializers>`__
        can be created if attachments are really needed.
+
+       This version adds attachments by putting them into a base64 encoded string.
+       This is not an optimal solution, it might get problematic if they are too
+       large to handle by the messaging queue, so check for a maximum size beforehand.
     """
     msg = Message()
     msg.__dict__.update(data)
+
+    current_app.extensions["mail"].send(msg)
+
+
+@shared_task
+def _send_email_with_attachments(data, attachments):
+    msg = Message()
+    msg.__dict__.update(data)
+
+    if attachments is not None:
+        for attachment in attachments["attachments"]:
+            rawdata = b64decode(attachment.get("base64"))
+            content_type = "application/octet-stream"
+            if "content_type" in attachment:
+                content_type = attachment.get("content_type")
+            disposition = None
+            if "disposition" in attachment:
+                disposition = attachment.get("disposition")
+            msg.attach(content_type=content_type, data=rawdata, disposition=disposition)
+
     current_app.extensions["mail"].send(msg)

tests/conftest.py

@@ -33,6 +33,7 @@ def email_task_app(request):
         CELERY_CACHE_BACKEND="memory",
         CELERY_EAGER_PROPAGATES_EXCEPTIONS=True,
         MAIL_SUPPRESS_SEND=True,
+        MAX_ATTACHMENT_SIZE=30,
     )
     FlaskCeleryExt(app)
 

tests/test_invenio_mail_tasks.py

@@ -2,6 +2,7 @@
 #
 # This file is part of Invenio.
 # Copyright (C) 2015-2018 CERN.
+# Copyright (C) 2023      University of Münster.
 #
 # Invenio is free software; you can redistribute it and/or modify it
 # under the terms of the MIT License; see LICENSE file for more details.
@@ -11,12 +12,8 @@
 
 from __future__ import absolute_import, print_function
 
-import os
-
-import pkg_resources
-from flask_mail import Attachment
-
-from invenio_mail.tasks import send_email
+from invenio_mail.errors import AttachmentOversizeException
+from invenio_mail.tasks import send_email, send_email_with_attachments
 
 
 def test_send_message_outbox(email_task_app):
@@ -70,3 +67,58 @@ def test_send_message_with_date(email_task_app):
 
         result_stream = email_task_app.extensions["invenio-mail"].stream
         assert result_stream.getvalue().find("Date: Tue, 23 Feb 2016") != -1
+
+
+def test_send_message_stream_with_attachment(email_task_app):
+    """Test sending a message with attachment using Task module."""
+    with email_task_app.app_context():
+        with email_task_app.extensions["mail"].record_messages() as outbox:
+            msg = {
+                "subject": "Test2",
+                "sender": "[email protected]",
+                "recipients": ["[email protected]"],
+            }
+            attachments = {
+                "attachments": [
+                    {
+                        "base64": "RWluIGVpbmZhY2hlciBTdHJpbmcK",
+                        "disposition": "filename.bin",
+                    },
+                ]
+            }
+            send_email_with_attachments(msg, attachments)
+
+            result_stream = email_task_app.extensions["invenio-mail"].stream
+            assert (
+                result_stream.getvalue().find("Content-Type: application/octet-stream")
+                != -1
+            )
+            assert (
+                result_stream.getvalue().find("Content-Disposition: filename.bin;")
+                != -1
+            )
+            assert result_stream.getvalue().find("RWluIGVpbmZhY2hlciBTdHJpbmcK") != -1
+
+
+def test_send_message_stream_with_oversize_attachment(email_task_app):
+    """Test sending a message with oversize attachment."""
+    with email_task_app.app_context():
+        with email_task_app.extensions["mail"].record_messages() as outbox:
+            msg = {
+                "subject": "Test2",
+                "sender": "[email protected]",
+                "recipients": ["[email protected]"],
+            }
+            attachments = {
+                "attachments": [
+                    {
+                        "base64": "RGllcyBpc3QgZGFzIEhhdXMgdm9tIE5pa29sYXVzCg==",
+                        "disposition": "filename.bin",
+                    },
+                ]
+            }
+            try:
+                send_email_with_attachments(msg, attachments)
+                assert False
+            except AttachmentOversizeException:
+                assert True