Fruster API Gateway

A convention based API Gateway that will handle incoming HTTP traffic, transform to bus message and publish on NATS bus.

Run

Install dependencies:

npm install

Start server:

npm start

During development nodemon is handy, it will watch and restart server when files changes:

# If you haven't already installed, do it:
npm install nodemon -g

# Start watch - any change to the project will now restart the server, or typ `rs` to trigger restart manually.
nodemon ./app.js

Configuration

Configuration is set with environment variables. All config defaults to values that makes sense for development.

# Applications log level (error|warn|info|debug|trace)
LOG_LEVEL = 'debug'

# Port API gateway listens on
PORT = 3000

# Allow origin for CORS
# Examples: `*`, `http://www.example.com`, `"http://www.example.com,http://localhost:9000"`
ALLOW_ORIGIN = "*""

# If stack traces should be included in error responses
# This might leak private implementation details that should not be exposed to outsiders
PRINT_STACKTRACE = true

# NATS servers, set multiple if using cluster
# Example: `"nats://10.23.45.1:4222,nats://10.23.41.8:4222"`
BUS = "nats://localhost:4222"

# Time we wait for reply from internal services.
BUS_TIMEOUT = '1s'

# Timeout before HTTP server returns 408.
# IMPORTANT: This must be more than `BUS_TIMEOUT`.
HTTP_TIMEOUT = '2s'

# Max size of requests that we can handle
# Examples: `1mb`, `100kb`
MAX_REQUEST_SIZE = '100kb'

# If fruster bus message data should be sent directly in response or if
# same JSON structure as internal bus messages should be kept
UNWRAP_MESSAGE_DATA = false

# User scopes required to connect to the fruster web bus
WEBSOCKET_PERMISSION_SCOPES = ["websocket.connect.id"],

# Subject for web sockets
WEBSOCKET_SUBJECT = "ws.*.>"

# Enable Server-Sent Events (SSE) functionality
# Default: false (disabled)
ENABLE_SSE = false

# Subject pattern for SSE events
SSE_SUBJECT = "sse.out.:userId.>"

# Maximum number of SSE connections per user
MAX_SSE_CONNECTIONS_PER_USER = 10

# SSE heartbeat interval
SSE_HEARTBEAT_INTERVAL = "30s"

Server-Sent Events (SSE)

The API Gateway includes support for Server-Sent Events (SSE), which allows for real-time server-to-client communication over HTTP. SSE is disabled by default and requires explicit configuration to enable.

For detailed information about the SSE implementation, see SSE.md.

License

This project is licensed under the terms of the MIT license