List users email (#446)

* Add management command to list users email.
* Accept email values in command line, send email.
* Workaround docker incompatibility issue with postgres:latest
See docker-library/postgres#1100

Author: juagargi

Diff for: .circleci/docker-compose.test-prod-db.yaml

@@ -2,7 +2,12 @@ version: '3'
 
 services:
   db:
-    image: postgres:latest
+    # Latest postgres docker image uses the new Debian bookworm and it is incompatible with some
+    # existing docker implementations. CircleCI runs one of those older implementations.
+    # Pinning the image to N-bullseye (prior Debian distribution) as a workaround.
+    # https://github.com/docker-library/postgres/issues/1100
+    # image: postgres:latest
+    image: postgres:12-bullseye
     expose:
       - "5432"
     environment:

Diff for: .circleci/docker-compose.yml

@@ -32,7 +32,12 @@ services:
       POSTGRES_PASSWORD: scionlab_rw_passw0rd
 
   coord-db:
-    image: postgres:latest
+    # Latest postgres docker image uses the new Debian bookworm and it is incompatible with some
+    # existing docker implementations. CircleCI runs one of those older implementations.
+    # Pinning the image to N-bullseye (prior Debian distribution) as a workaround.
+    # https://github.com/docker-library/postgres/issues/1100
+    # image: postgres:latest
+    image: postgres:12-bullseye
     networks:
       - coord_net
     expose:

Diff for: scionlab/management/commands/mass_email.py

@@ -0,0 +1,110 @@
+# Copyright 2023 ETH Zurich
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+import sys
+
+from typing import List
+from django.conf import settings
+from django.core.management.base import BaseCommand, CommandParser
+from django.core.mail import EmailMessage
+
+from scionlab.models.user import User
+
+
+class Command(BaseCommand):
+    help = 'List or send a message to the unique emails of the users in alphabetical order'
+
+    def add_arguments(self, parser: CommandParser) -> None:
+        parser.add_argument('-a', '--action', type=str, required=True,
+                            choices=['list', 'send'],
+                            help='Action of the command: list or send')
+        parser.add_argument('--subject', type=str, required=False,
+                            help='Subject of the email to send')
+        parser.add_argument('--body', type=argparse.FileType('r'), default='-',
+                            help='Input file to read the body of the email from')
+        parser.add_argument('--skip_blocks', type=int, default=0,
+                            help='skip N initial blocks of recipients. Useful to continue ' +
+                            'sending after a crash')
+
+    def handle(self, *args, **kwargs):
+        action = kwargs['action']
+        if action == 'list':
+            self.list()
+        elif action == 'send':
+            self.send(**kwargs)
+
+    def list(self):
+        # print active users emails:
+        for email in self._obtain_active_emails():
+            print(email)
+
+        # report user stats:
+        inactive = []
+        active = []
+        for u in User.objects.all():
+            if not u.is_active:
+                inactive.append(u)
+            else:
+                active.append(u)
+        print(f'--------------------------- inactive: {len(inactive)}')
+        print(f'--------------------------- active: {len(active)}')
+
+    def send(self, **kwargs):
+        # retrieve the email parameters, or complain
+        if 'subject' not in kwargs or kwargs['subject'] is None:
+            exit('Need a subject')
+        subject = kwargs['subject']
+        if kwargs['body'] == sys.stdin:
+            print('Type the body of the email, end with ^D')
+        with kwargs['body'] as f:
+            body = f.read()
+        skip_blocks = kwargs['skip_blocks']
+
+        self._send(
+            subject=subject,
+            body=body,
+            skip_blocks=skip_blocks,
+        )
+
+    def _send(self, subject: str, body: str, skip_blocks: int):
+        recipients = self._obtain_active_emails()
+        block_count = (len(recipients) - 1) // settings.MAX_EMAIL_RECIPIENTS + 1
+        for b in range(skip_blocks, block_count):
+            # the recipients are a subset of the total
+            dest = recipients[
+                b*settings.MAX_EMAIL_RECIPIENTS:
+                (b + 1) * settings.MAX_EMAIL_RECIPIENTS]
+            # prepare the email and send it
+            msg = EmailMessage(
+                subject,
+                body,
+                settings.DEFAULT_FROM_EMAIL,    # From
+                [],  # To
+                bcc=dest,
+            )
+            msg.send()
+            print(f'sent {b+1}/{block_count} -> {dest}')
+        print('done')
+
+    def _obtain_active_emails(self) -> List[str]:
+        emails = User.objects.filter(
+            is_active=True,
+            ).values_list('email', flat=True).order_by('email').distinct()
+        return emails
+
+
+def exit(msg: str):
+    print(msg)
+    sys.exit(1)

Diff for: scionlab/settings/common.py

@@ -151,6 +151,9 @@ class VPNKeygenConf:
 # Location of the scion-pki command to generate TRCs.
 SCION_PKI_COMMAND = os.path.join(BASE_DIR, 'static_bin', 'scion-pki')
 
+# Maximum number of recipients that the SMTP server we have can handle at once.
+MAX_EMAIL_RECIPIENTS = 100
+
 # ##### DEBUG CONFIGURATION ###############################
 ALLOWED_HOSTS = []
 DEBUG = False