@systemfsoftware/effect-readiness

Composable readiness probes and condition polling for Effect applications, containers, and micro-VMs.

Installation

pnpm add @systemfsoftware/effect-readiness

Features

• Protocol Agnostic: Wait for TCP port connectivity, HTTP endpoint health (2xx responses), or stdout/stderr log stream patterns.
• Pure Core / Imperative Shell: Decoupled workflow decisions (resolveProbe, evaluateProbe) and pure schemas with effectful cell-based execution (awaitCondition).
• Platform Separation: Pluggable network dialing and stream reading through the HostProber and LogSource service contracts. Built-in NodeHostProber using @effect/platform-node.
• Interruption & Resource Safety: Clean socket disposal with prompt release upon check completion or timeout.

Usage

import { Readiness } from '@systemfsoftware/effect-readiness'
import { Effect, Layer } from 'effect'

const target = Readiness.target([
  { guest: 8080, host: '127.0.0.1', hostPort: 32768 },
])
  .withTimeout(10_000)
  .withPoll(100)

// Wait for TCP port connectivity
const checkTcp = target.awaitCondition(Readiness.Wait.forTcp(8080))

// Wait for HTTP endpoint readiness
const checkHttp = target.awaitCondition(Readiness.Wait.forHttp('/healthz', 8080))

// Wait for stdout/stderr log line pattern
const checkLog = target.awaitCondition(Readiness.Wait.forLog('server listening on 8080'))

// Execute with built-in Node driver and a provided LogSource
const program = checkHttp.pipe(
  Effect.provide(
    Layer.merge(
      Readiness.NodeHostProber.layer,
      Layer.succeed(Readiness.LogSource, {
        entries: Effect.succeed(['booting', 'server listening on 8080']),
      }),
    ),
  ),
)