Dispatch
Messages come in, messages go out
The dispatch program is designed to front all externally driven changes to the Sparks platform.
What is an externally driven change? A user who wants to do something. They (or more precisely our website) issues a command that arrives at the dispatcher. The dispatcher then:
- Validates the message using a schema from
sparks-schemas - Authorizes that the user is allowed to make this change
- Puts the message onto a message bus for services to take actions
- Returns a response that says yea or ney
At the return stage the user (well software) only knows that we accepted the message. Any actual changes happen further down.
Moving parts:
- index.ts: In / validate / auth / dispatch / respond
- queue.ts: In, currently reads firebase queue for messages
- validate.ts: Validates the command in the message using
sparks-schemas - auth.ts: Auth, checks a whole bunch of shit
- dispatch.ts: Out, adds the message to kinesis
Environment:
The following variables are required:
FIREBASE_DATABASE_URL: the database url
KINESIS_STREAM: name of kinesis stream
Running
To run it you need a firebase and a firebase credentials.json file:
npm install
npm start