The main entry point to send messages is a predefined Kafka topic: notifications.outbox. Messages from that topic would be processed by notifications backend and sent to different services according to user's preferences.
This is a microservice responsible for dispatching preformatted notifications to different endpoints.
Message: A JSON payload with predefined fields: Application, Event type,
Severity, Message and Timestamp.
Dispatcher: Component that is responsible for receiving incoming messages and deciding (based on filters) which endpoint should receive the message.
Filter: A combination of Application, Event type and Severity sets that
will be compared against the message received. Once there is a match,
endpoints associated with this filter record would be triggered.
Endpoint: A set of properties that would be enough to initiate a web request to a URL (which is also part of the properties) of a notification service. Good examples for such services would be slack, sms senders e.t.c.
The process starts when a message arrives on notifications.outbox Kafka topic.
This message is passed to a dispatcher.
Dispatcher is responsible to find out which endpoints should be triggered. Once the endpoints were identified, an ActiveJob is fired for each endpoint with details of the message to send and endpoint properties.
The job is responsible to initiate a web request with endpoint's details, format the message to fit into endpoint's API and make sure the message has arrived to the recipient (endpoint).
Start from cloning this repository
git clone https://github.com/RedHatInsights/notifications-backend.gitInstall all relevant gems
bundle installMake sure you have working docker and docker-compose already set up.
From project's root you can simply run
bin/setup_devit will spin up zookeper, kafka and redis containers ready and waiting for connections.
For more details look at docker/docker-compose.yml.
To start kafka listener run
racecar JobCreatorConsumerTo start resque job consumer run
QUEUE=unsorted_notifications rake environment resque:workThere is a rake task to inject messages into a dev setup:
rake notifications:sendadd --help to see more options.
This project uses UUID-typed columns, which relies on pgcrypto extension which may not be shipped with PostgreSQL by default. On Fedora this extension lives in the postgresql-contrib package. Official postgres docker image come bundled with this extension.