Certain SMTP hosts limit the total number of messages that can be
sent within a window, for instance, X / 24 hours. The concurrency
and message rate controls can only limit that to a max of
1 messages / second, without a global cap.
This commit introduces a simple sliding window rate limit feature
that counts the number of messages sent in a specific window, and
upon reaching that limit, waits for the window to reset before
any more messages are pushed out globally across any number of
campaigns.
Context: https://github.com/knadh/listmonk/issues/119
A new toggle switch in Settings -> Privacy, which is off by
default, allows campaign views (pixel) and link clicks to function
without registering the subscriber ID against view and click
events, anonymising tracking. When off, the subscriber UUIDs in
view and link tracking URLs are removed, anonymising subscriber
information from HTTP logs as well.
This is a major feature that builds upon the `Messenger` interface
that has been in listmonk since its inception (with SMTP as the only
messenger). This commit introduces a new Messenger implementation, an
HTTP "postback", that can post campaign messages as a standard JSON
payload to arbitrary HTTP servers. These servers can in turn push them
to FCM, SMS, or any or any such upstream, enabling listmonk to be a
generic campaign messenger for any type of communication, not just
e-mails.
Postback HTTP endpoints can be defined in settings and they can be
selected on campaigns.
- Added as a setting in the settings UI.
- Refactor Messenger.Push() method to accept messenger.Message{}
instead of a growing number of positional arguments.
This is a major breaking change that moves away from having the
entire app configuration in external TOML files to settings being
in the database with a UI to update them dynamically.
The app loads all config into memory (app settings, SMTP conf)
on boot. "Hot" replacing them is complex and it's a fair tradeoff
to instead just restart the application as it is practically
instant.
A new `settings` table stores arbitrary string keys with a JSONB
value field which happens to support arbitrary types. After every
settings update, the app gracefully releases all resources
(HTTP server, DB pool, SMTP pool etc.) and restarts itself,
occupying the same PID. If there are any running campaigns, the
auto-restart doesn't happen and the user is prompted to invoke
it manually with a one-click button once all running campaigns
have been paused.
- Refactor campaign.Message into campaign.Message and
campaign.CampaignMessage
- Remove ad-hoc goroutines (flawed approach) that were used to push
admin and optin notifications.
- Provision for largscale pushing of ad-hoc, non-campaign messages
such as transactional messages (in the future).
Kailash Nadh