AnzuSystems Notification-Server by Petit Press a.s. (www.sme.sk)

Provides WebSocket functionality among Anzusystems' projects.

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Introduction

Notification Server is a simple WebSocket server which requires only these technologies:

• Google Pub/Sub
• Users externally authenticated with a JWT stored in cookies.
  • note: Notification Server only validates token according a public certificated.

Notification Server supports horizontal scaling by creating a Pub/Sub subscription for each running instance.

Pushing messages to Notification Server

To send a PubsubMessage you must define following fields:

• attributes.targetSsoUserIds - array of user ids which should receive a message
• attributes.eventName - string of an event name
• data (optional) - any string (e.g. serialized json) which will be sent to target sso user ids

Configuration

Configure these environment variables:

• SSO_JWT_COOKIES - array of cookies names where is a JWT stored. It might contain only one cookie name, but for security purpose it's recommended to split the token into two parts:
  • header and payload into not http-only cookie
  • signature into http- only cookie
• SSO_JWT_ALGORITHM - the algorithm used to encrypt a JWT (e.g. ES256)
• PUBSUB_TOPIC - string name of the Pub/Sub topic name.
• APP_INSTANCE_NAME - string name of the instance. If you run Notification Server on multiple instances (e.g. containers), use the unique name of the container. Pub/Sub will create on a startup subscription for each container to a topic defined in PUBSUB_TOPIC.
• WEBSOCKET_SERVER_CORS - regex cors url from which is connection made of
• WEBSOCKET_SERVER_PORT - server port for WebSocket server
• LOG_LEVEL - any value of Winston's logger levels
• GCLOUD_PROJECT - your project name in Google Pub/Sub, or for a development purpose use "emulator-project"
• GOOGLE_APPLICATION_CREDENTIALS - your path to a Google Pub/Sub credentials json, or for a development purpose don't define this env
• PUBSUB_EMULATOR_HOST - only for a development purpose, define a host to an emulator host

Start prod server

Run prod node server:

bin/run prod

For a development run, read README-DEV.md.