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

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

• Very performant with almost no CPU and memory usage
• Under 500 lines of code
• Secure Real-time Event Stream via SSE - requires the use of broker-client
• Supports CORS
• Add users with admin token permission
• Multi-tenant
• Supports SSL - full end-to-end encryption
• Provides user authentication with JWTs or HTTP Basic
• Secure passwords with Argon2 encoding
• Uses Global NTP servers and doesn't rely on your local server time
• Insert event via JSON POST request
• Sync latest events on SSE client connection
• Auto-provision and renews SSL cert via LetsEncrypt
• Verify endpoint for external services using Broker user system like portal

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-client - the official front-end client for broker
• broker-hook - the official react hook for broker
• React Hook Form - Best form library for React
• React Debounce Input - React input for Real-time Submission (Edit in Place forms)

Broker FAQ

• Why compete against Parse Server and Firebase?

Firebase is not open-source, is not free, and has complicated pricing. Parse Server doesn't have real-time features and is about 30,000 LOC of JS.

• Will broker work with mobile apps?

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

POST /users 

• public endpoint
• POST JSON to create a user

{"username":{...}, "password":{...}, "admin_token":{...}, "tenant_name":{...}}

• where {...} is for username is a string, password is a string, admin_token is a string, and tenant_name is a string
• 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

will return 200 or 500 or 400

For JWT Auth: Step 2 - login with the user

POST /login 

• public endpoint
• POST JSON to login

{"username":{...}, "password":{...}}

• where {...} is for username is a string and password is a string

will return

{"jwt":{...}}

• where {...} is a JWT (string)

Step 3 - connect to SSE

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

POST /insert 

• authenticated endpoint (Authorization: Bearer {jwt}) or (Authorization: Basic {username:password})
• POST JSON to insert an event

{"event":{...}, "data":{...}}

• where {...} is for the event a string and data is any JSON you want

will return: 200 or 500 or 400 or 401

Optional - verify user

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

Install

cargo install broker

• the origin can be passed in as a flag - default *
• the port can be passed in as a flag - default 8080 - can only be set for unsecure connections
• the jwt_expiry (for jwts) can be passed in as a flag - default 86400
• the jwt_secret (for jwts) should be passed in as a flag - default secret
• the secure flag (https) and can be true or false - default false
• the certs flag is the storage path of LetsEncrypt certs - default certs
• the db flag is the path where the embedded database will be saved - default tmp
• the domain flag is the domain name (e.g. api.broker.com) of the domain you want to register with LetsEncrypt - must be fully resolvable
• the admin_token flag is the password for the admin to add users - default letmein
• production example: ./broker --secure="true" --admin_token"23ce4234@123$" --jwt_secret="xTJEX234$##$" --domain="api.broker.com"

Service

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

TechStack

• Tide
• RocksDB

Inspiration

• React Hooks
• Meteor
• MongoDB
• Pusher
• Event Sourcing
• Best in Place
• Brock Whitten