Previously, we had an architecture where CSS inlining for emails was
done at provision time in inline_email_css.py. This was necessary
because the library we were using for this, Premailer, was extremely
slow, and doing the inlining for every outgoing email would have been
prohibitively expensive.
Now that we've migrated to a more modern library that inlines the
small amount of CSS we have into emails nearly instantly, we are able
to remove the complex architecture built to work around Premailer
being slow and just do the CSS inlining as the final step in sending
each individual email.
This has several significant benefits:
* Removes a fiddly provisioning step that made the edit/refresh cycle
for modifying email templates confusing; there's no longer a CSS
inlining step that, if you forget to do it, results in your testing a
stale variant of the email templates.
* Fixes internationalization problems related to translators working
with pre-CSS-inlined emails, and then Django trying to apply the
translators to the post-CSS-inlined version.
* Makes the send_custom_email pipeline simpler and easier to improve.
Signed-off-by: Daniil Fadeev <fadeevd@zulip.com>
This is the behaviour inherited from Django[^1]. While setting the
password to empty (`email_password = `) in
`/etc/zulip/zulip-secrets.conf` also would suffice, it's unclear what
the user would have been putting into `EMAIL_HOST_USER` in that
context.
Because we previously did not warn when `email_password` was not
present in `zulip-secrets.conf`, having the error message clarify the
correct configuration for disabling SMTP auth is important.
Fixes: #23938.
[^1]: https://docs.djangoproject.com/en/4.1/ref/settings/#std-setting-EMAIL_HOST_USER
To explain the rationale of this change, for example, there is
`get_user_activity_summary` which accepts either a `Collection[UserActivity]`,
where `QuerySet[T]` is not strictly `Sequence[T]` because its slicing behavior
is different from the `Protocol`, making `Collection` necessary.
Similarily, we should have `Iterable[T]` instead of `List[T]` so that
`QuerySet[T]` will also be an acceptable subtype, or `Sequence[T]` when we
also expect it to be indexed.
Signed-off-by: Zixuan James Li <p359101898@gmail.com>
This applies a commonly-used, though non-RFC, header which suppresses
auto-replies to the message. There is a small chance that this will
result in bad filters thinking the messages *from Zulip* are
themselves auto-replies, but this seems a small risk.
Fixes: #13193.
Fixes#20132.
EMAIL_HOST_USER without EMAIL_HOST_PASSWORD is not going to be a valid
configuration, and may result from making mistake in correctly setting
it in the secrets file and end up being a non-obvious cause of failure
to send email. Logging an error will be useful for detecting it. Further
conditions can be added to the function in the future.
It is better to press on, than stop halfway through due to a user
whose email no longer works. The exception is already logged, which
is sufficient here, as this is generally run interactively.
Calling `email.save()` is only needed if we altered `email.address`;
it is unnecessary if we called `email.users.add(...)` which will have
done its own INSERT.
This fixes two bugs: the most obvious is that there is a race where a
ScheduledEmail object could be observed in the window between creation
and when users are added; this is a momentary instance when the object
has no users, but one that will resolve itself.
The more subtle is that .save() will, if no records were found to be
updated, _re-create_ the object as it exists in memory, using an
INSERT[1]. Thus, there is a race with `deliver_scheduled_emails`
between when the users are added, and when `email.save()` runs:
1. Web request creates ScheduledEmail object
2. Web request creates ScheduledEmailUsers object
3. deliver_scheduled_emails locks the former, preventing updates.
4. deliver_scheduled_emails deletes both objects, commits, releasing lock
5. Web request calls `email.save()`; UPDATE finds no rows, so it
re-creates the ScheduledEmail object.
6. Future deliver_scheduled_emails runs find a ScheduledEmail with no
attending ScheduledEmailUsers objects
Wrapping the logical creation of both of these in a single transaction
avoids both of these races.
[1] https://docs.djangoproject.com/en/3.2/ref/models/instances/#how-django-knows-to-update-vs-insert
Only clear_scheduled_emails previously took a lock on the users before
removing them; make deliver_scheduled_emails do so as well, by using
prefetch_related to ensure that the table appears in the SELECT. This
is not necessary for correctness, since all accesses of
ScheduledEmailUser first access the ScheduledEmail and lock it; it is
merely for consistency.
Since SELECT ... FOR UPDATE takes an UPDATE lock on all tables
mentioned in the SELECT, merely doing the prefetch is sufficient to
lock both tables; no `on=(...)` is needed to `select_for_update`.
This also does not address the pre-existing potential deadlock from
these two use cases, where both try to lock the same ScheduledEmail
rows in opposite orders.
No codepath except tests passes in more than one user_profile -- and
doing so is what makes the deduplication necessary.
Simplify the API by making it only take one user_profile id.
Previously, the output would make it look like we sent an actual email
to the first user in the dry_run output, which is very confusing.
The `dry_run` code path already prints all the accounts that would
have been emailed at the end, so there's no reason to have this line
before the dry_run check.
Additionally, we move after the `get_connection` check because
failures at that stage shouldn't result in logging an attempt to send
an email.
An organization with at most 5 users that is behind on payments isn't
worth spending time on investigating the situation.
For larger organizations, we likely want somewhat different logic that
at least does not void invoices.
This makes it parallel with deliver_scheduled_messages, and clarifies
that it is not used for simply sending outgoing emails (e.g. the
`email_senders` queue).
This also renames the supervisor job to match.
Django's default SMTP implementation can raise various exceptions
when trying to send an email. In order to allow Zulip calling code
to catch fewer exceptions to handle any cause of "email not
sent", we translate most of them into EmailNotDeliveredException.
The non-translated exceptions concern the connection with the
SMTP server. They were not merged with the rest to keep some
details about the nature of these.
Tests are implemented in the test_send_email.py module.
Commit 9afde790c6 introduced a bug
concerning outgoing emails inside the development environment. These
emails are not supposed to use a real connection with a mail
server as the send_messages function is overwritten inside the
EmailLogBackEnd class.
The bug was happening inside the initialize_connection function that
was introduced in the above-mentioned commit. This function is used
to refresh the connection with an SMTP server that would have closed
it. As the socket used to communicate with the server is not
initialized inside the development environment this function was
wrongly trying to send no-op commands.
The fix just checks that the connection argument of the function is
an EmailLogBackEnd object before trying the no-op command.
Additionally as it is sometimes useful to be able to send outgoing
emails inside the development environment the get_forward_address
function is used to check if a real connection exists between Zulip
and the server. If it is the case, as EmailLogBackEnd is a subclass
of smtp.EmailBackend, the connection will be nicely refreshed.
This commit was tested manually by checking that the console prints
correctly that an email is sent to the user when it signs in inside
the development environment. It was also tested when a mail provider
is specified and the mails were correctly received.
Add a `--dry-run` flag to send_custom_email management command
in order to provide a mechanism to verify the emails of the recipients
and the text of the email being sent before actually sending them.
Add tests to:
- Check that no emails are actually sent when we are in the dry-run mode.
- Check if the emails are printed correctly when we are in the dry-run mode.
Fixes#17767
Previously the outgoing emails were sent over several SMTP
connections through the EmailSendingWorker; establishing a new
connection each time adds notable overhead.
Redefine EmailSendingWorker worker to be a LoopQueueProcessingWorker,
which allows it to handle batches of events. At the same time, persist
the connection across email sending, if possible.
The connection is initialized in the constructor of the worker
in order to keep the same connection throughout the whole process.
The concrete implementation of the consume_batch function is simply
processing each email one at a time until they have all been sent.
In order to reuse the previously implemented decorator to retry
sending failures a new method that meets the decorator's required
arguments is declared inside the EmailSendingWorker class. This
allows to retry the sending process of a particular email inside
the batch if the caught exception leaves this process retriable.
A second retry mechanism is used inside the initialize_connection
function to redo the opening of the connection until it works or
until three attempts failed. For this purpose the backoff module
has been added to the dependencies and a test has been added to
ensure that this retry mechanism works well.
The connection is closed when the stop method is called.
Fixes: #17672.
This was introduced in 8321bd3f92 to serve as a sort of drop-in
replacement for zerver.lib.queue.queue_json_publish, but its use has
been subsequently cut out (e.g. `9fcdb6c83ac5`).
Remote its last callsite.
django.utils.translation.ugettext is a deprecated alias of
django.utils.translation.gettext as of Django 3.0, and will be removed
in Django 4.0.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Amazon SES has a limit on the size of address fields, and rejects
emails with too-long "From" combinations of name and address. This
limit is set to 320 bytes and comes from an RFC limitation on the
size of addresses. This RFC standard states that an email address
should not be composed of a local part (before the '@') longer than
64 bytes and a domain part (after the '@') longer than 255 bytes.
It is possible that Amazon SES misinterprets this limitation as it
checks the length of the combination of the name and the email
address of the sender.
To ensure that this problem is not encountered in the send_email
module of Zulip the length of this combination is now checked
against this limit and the from_name field is removed to only
keep the from_address field when it is necessary in order to
stay below 320 bytes.
If the from_address field alone is longer than 320 bytes the
sending process will raise an SMTPDataError exception.
Tests for this new check are added to the backend test suite in
order to test if build_email correctly outputs an email with filled
from_name and from_address fields when the total length is lower
than 320 bytes and that it correctly throws the from_name field
away when necessary.
Fixes: #17558.
These procedures should be done atomically overall, with the exception
of the code that sends events to avoid block if there's a delay
communicating with Tornado.
We add the savepoint=False on underlying function that already
executes inside an atomic context - to avoid the overhead of creating
savepoints where they aren't needed.
The main race conditions, which actually happened in production was with
concurrent execution of deliver_email and clear_scheduled_emails.
clear_scheduled_emails could delete all email.users in the middle of
deliver_email execution, causing it to pass empty to_user_ids list to
send_email. We mitigate this by getting the list of user ids in a single
query and moving forward with that snapshot, not having to worry about
database data being mutated anymore.
clear_scheduled_emails had potential race conditions with concurrent
execution of itself due to not locking the appropriate rows upon
selecting them for the purpose of potentially deleting them. FOR UPDATE
locks need to be acquired to prevent simultaneous mutation.
Tested manually with some print+sleep debugging to make some races
happen.
fixes #zulip-2k (sentry)
Daniil Fadeev
Alex Vandiver
Anders Kaseorg
Zixuan James Li
Mateusz Mandera
Tim Abbott
PIG208
Vishnu KS
Suyash Vardhan Mathur
Cyril Pletinckx
Siddharth Asthana