Broker - Real-time BaaS (Backend as a Service)

crates.io

Purpose

The purpose of this service is to be your real-time BaaS (Backend as a Service).

Broker is a SSE message broker that requires you write no backend code to have a full real-time API.

Broker is born from the need that rather than building a complex REST API with web-sockets and a SQL database to provide reactive web forms (like for React) there must be a simpler way.

Broker follows an insert-only/publish/subscribe paradigm rather than a REST CRUD paradigm.

Features

How it works

In Broker you create a user, login, then insert an event with its data. Broker then publishes the event via SSE.

When the client first subscribes to the SSE connection all the latest events and data is sent to the client. Combined with sending the latest event via SSE when subscribed negates the necessity to do any GET API requests in the lifecycle of an event.

The side-effect of this system is that the latest event is the schema. This is pure NoSQL as the backend is agnostic to the event data.

Recommeded Services/Libraries to use with Broker

Broker FAQ

Yes with React Native. There may be native 3rd party libraries for SSE that work. In the future official libraries may be made available for native platforms.

Use

Step 1 - create a user

html POST /create_user - public endpoint json { "username": "bob", "password": "password1", "admin_token": "letmein", "tenant_name": "tenant_1", "email": "bob@hotmail.com", "scopes": ["news:get", "news:post"], "data": { "name": "Robert Wieland", "image": "https://img.com/bucket/123/123.jpg" } } - admin_token is required and can be set in the command args - it is for not allowing everyone to add a user - the default is letmein - email and data is an optional field

will return 200 or 500 or 400

For JWT Auth: Step 2 - login with the user

html POST /login - public endpoint json { "username": "bob", "password": "password1" }

will return json { "jwt": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE2MTc2NzQ5MTUsImlhdCI6MTYxNzU4ODUxNSwiaXNzIjoiRGlzcGF0Y2hlciIsInN1YiI6ImZvbyJ9.OwiaZJcFUC_B0CA0ffRZVTWKRf5_vQ7vt5USNJEeKRE" } - note: iat is the issue time, exp is the expiry time, sub is the username, iss is Broker, while aud is the user scopes joined with a comma like in this example news:get,news:post - note: if you need to debug your JWT then visit jwt.io

Step 3 - connect to SSE

html GET /sse - authenticated endpoint (Authorization: Bearer {jwt}) or (Authorization: Basic {username:password}) - connect your sse-client to this endpoint using broker-client - note: broker-client uses fetch as eventsource doesn't support headers

Step 4 - insert an event

html POST /insert - authenticated endpoint (Authorization: Bearer {jwt}) or (Authorization: Basic {username:password}) json { "event": "test", "data": { "name": "robert", "image": "https://img.com/bucket/123/123.jpg" } }

will return: 200 or 500 or 400 or 401

Optional - verify user

html GET /verify - authenticated endpoint (Authorization: Bearer {jwt}) or (Authorization: Basic {username:password}) - verifies that the user is authenticated on broker - used for external services like portal

will return: 200 or 500 or 401

Optional - revoke user

html POST /revoke_user - public endpoint json { "admin_token": "letmein", "username": "bob" }

will return: 200 or 500 or 400 or 401 - note: revoked users cannot login

Optional - unrevoke user

html POST /unrevoke_user - public endpoint json { "admin_token": "letmein", "username": "bob" }

will return: 200 or 500 or 400 or 401

Optional - list users

html POST /list_users - public endpoint json { "admin_token": "letmein", }

will return: 200 or 500 or 400 or 401

200 - will return an array of objects json [ { "id": "69123c04-fa42-4193-a6c5-ab2fc27658b1", "password": "***", "revoked": false, "tenant_name": "tenant_1", "username": "bob", "email": "bob@hotmail.com", "scopes": ["news:get", "news:post"], "data": { "name": "Robert Wieland", "image": "https://img.com/bucket/123/123.jpg" } } ] - note: email and data can be null

Optional - get user

html POST /get_user - public endpoint json { "admin_token": "letmein", "username": "bob" }

will return: 200 or 500 or 400 or 401

200 - will return an array of objects json { "id": "69123c04-fa42-4193-a6c5-ab2fc27658b1", "password": "***", "revoked": false, "tenant_name": "tenant_1", "username": "bob", "email": "bob@hotmail.com", "scopes": ["news:get", "news:post"], "data": { "name": "Robert Wieland", "image": "https://img.com/bucket/123/123.jpg" } } - note: email and data can be null

Optional - update user

html POST /update_user - public endpoint json { "admin_token": "letmein", "username": "bob", "tenant_name": "tenant_2", "password": "new_password", "email": "bober@hotmail.com", "scopes": ["news:get", "news:post"], "data": { "name": "Robert Falcon", "image": "https://img.com/bucket/123/1234.jpg" } } - note: tenant_name, password, email, data are optional fields

will return: 200 or 500 or 400 or 401

Optional - Health Check

html GET or HEAD / - public endpoint

will return: 200

Install

cargo install broker

Service

There is an example systemctl service for Ubuntu called broker.service in the code

TechStack

Inspiration