streaming-core

Streaming, done simply. A compact Go service that emits a continuous stream of numbers over Server‑Sent Events (SSE). Designed for clarity, testability, and production readiness.

Features

• Incrementing integer feed over SSE
• Configurable timing and CORS via environment
• Resume support with Last-Event-ID
• Optional start and limit query params
• Graceful shutdown on SIGINT/SIGTERM

API

GET /stream

Sends event: number messages; each message contains the current integer. The id equals the integer value to enable simple resume.

Query params:

• intervalMs: integer; delay between events. Default: 100
• start: integer; first number to emit. Default: 0
• limit: integer; maximum messages before the stream ends. Default: unlimited

Headers:

• Last-Event-ID: resume from the next integer after this id

Other endpoints:

• / index
• /health liveness probe

Configuration

Environment variables:

• PORT server port. Default: 8080
• STREAM_INTERVAL_MS default emit interval. Default: 100
• CORS_ALLOW_ORIGIN value for Access-Control-Allow-Origin. Default: *

Getting started

go run .

curl -N http://localhost:8080/stream

Custom interval and bounded stream:

curl -N "http://localhost:8080/stream?intervalMs=250&start=10&limit=5"

Browser example:

<script>
  const s = new EventSource('/stream');
  s.addEventListener('number', e => console.log(e.lastEventId, e.data));
</script>

Production notes

• SSE requires response streaming; ensure proxies do not buffer
• Prefer a process manager to forward signals for clean shutdown
• For cross‑origin use, pin CORS_ALLOW_ORIGIN to known origins

License

MIT