Add management command to send password reset emails.

This is a convenient tool to have around.

We require an unusual argument value of "YES" to send to everyone on
the server, since that's something one should do with a great deal of
care.

zerver/management/commands/send_password_reset_email.py

@@ -0,0 +1,87 @@
+from __future__ import absolute_import
+
+import logging
+from typing import Any
+
+from argparse import ArgumentParser
+from django.core.management.base import BaseCommand, CommandError
+from django.conf import settings
+from django.core.mail import send_mail, BadHeaderError
+from zerver.forms import PasswordResetForm
+from zerver.models import UserProfile, get_user_profile_by_email, get_realm
+from django.template import loader
+from django.core.mail import EmailMultiAlternatives
+
+from django.utils.http import urlsafe_base64_encode
+from django.utils.encoding import force_bytes
+
+
+from django.contrib.auth.tokens import default_token_generator
+
+class Command(BaseCommand):
+    help = """Send email to specified email address."""
+
+    def add_arguments(self, parser):
+        # type: (ArgumentParser) -> None
+        parser.add_argument('--to', metavar='<to>', type=str,
+                            help="email of user to send the email")
+        parser.add_argument('--realm', metavar='<realm>', type=str,
+                            help="realm to send the email to all users in")
+        parser.add_argument('--server', metavar='<server>', type=str,
+                            help="If you specify 'YES' will send to everyone on server")
+
+    def handle(self, *args, **options):
+        # type: (*Any, **str) -> None
+        if options["to"]:
+            users = [get_user_profile_by_email(options["to"])]
+        elif options["realm"]:
+            realm = get_realm(options["realm"])
+            users = UserProfile.objects.filter(realm=realm, is_active=True, is_bot=False,
+                                               is_mirror_dummy=False)
+        elif options["server"] == "YES":
+            users = UserProfile.objects.filter(is_active=True, is_bot=False,
+                                               is_mirror_dummy=False)
+        else:
+            raise RuntimeError("Missing arguments")
+        self.send(users)
+
+    def send(self, users, domain_override=None,
+             subject_template_name='registration/password_reset_subject.txt',
+             email_template_name='registration/password_reset_email.txt',
+             use_https=True, token_generator=default_token_generator,
+             from_email=None, request=None, html_email_template_name=None):
+        """Sends one-use only links for resetting password to target users
+
+        """
+        for user_profile in users:
+            context = {
+                'email': user_profile.email,
+                'domain': user_profile.realm.host,
+                'site_name': "zulipo",
+                'uid': urlsafe_base64_encode(force_bytes(user_profile.pk)),
+                'user': user_profile,
+                'token': token_generator.make_token(user_profile),
+                'protocol': 'https' if use_https else 'http',
+            }
+
+            logging.warning("Sending %s email to %s" % (email_template_name, user_profile.email,))
+            self.send_mail(subject_template_name, email_template_name,
+                           context, from_email, user_profile.email,
+                           html_email_template_name=html_email_template_name)
+
+    def send_mail(self, subject_template_name, email_template_name,
+                  context, from_email, to_email, html_email_template_name=None):
+        """
+        Sends a django.core.mail.EmailMultiAlternatives to `to_email`.
+        """
+        subject = loader.render_to_string(subject_template_name, context)
+        # Email subject *must not* contain newlines
+        subject = ''.join(subject.splitlines())
+        body = loader.render_to_string(email_template_name, context)
+
+        email_message = EmailMultiAlternatives(subject, body, from_email, [to_email])
+        if html_email_template_name is not None:
+            html_email = loader.render_to_string(html_email_template_name, context)
+            email_message.attach_alternative(html_email, 'text/html')
+
+        email_message.send()