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    @k8ts/health
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    0.1.1 • Public • Published

    @k8ts/health

    A helper library for implementing Kubernetes heath checks and graceful HTTP shutdown in Node applications.

    Installation

    Install using your preferred package manager:

    $ yarn add @k8ts/health
    $ pnpm add @k8ts/health
    $ npm install @k8ts/health

    Usage

    @k8ts/health supports many different configuration options, can integrate with existing HTTP frameworks, can run tasks on termination, and and can gracefully handle in-flight HTTP requests. See below for more details.

    To get started:

    1. First, create a new Health instance to track your application health:

      import {Health} from '@k8ts/health'
      
      const health = new Health()
    2. Then once your application is ready to receive requests, mark its status as ready:

      health.markReady()
    3. You will need to expose this health status to Kubernetes via an HTTP endpoint, the easiest way to do this is to start a standalone health server with startProbeServer():

      import {startProbeServer} from '@k8ts/health'
      
      startProbeServer(health)

      This will serve the endpoints /healthz and /readyz on port 4000 (all configurable, see below). These endpoints can thus be referenced from the liveness, readiness, and startup probes.

    API

    Read the API documentation.

    Examples

    Standalone Health Server

    To serve a standard Node http.Server for the liveness and readiness endpoints:

    import {Health, startProbeServer} from '@k8ts/health'
    const health = new Health()
    
    startProbeServer(health)

    To create a new Node http.Server, but not automatically listen:

    import {Health, createProbeServer} from '@k8ts/health'
    const health = new Health()
    
    const server = createProbeServer(health)

    Express

    To mark the application as ready when the server is listening, and gracefully handle in-flight requests during termination:

    import {Health, gracefulHttpTerminatorTask} from '@k8ts/health'
    import express from 'express'
    
    const health = new Health()
    const app = express()
    
    // ...
    
    const server = app.listen(3000, () => {
      health.markReady()
    })
    
    health.beforeTermination(gracefulHttpTerminatorTask(server))

    To integrate the liveness and readiness endpoints into an existing Express application:

    import {Health, createLivenessProbeListener, createReadinessProbeListener} from '@k8ts/health'
    import express from 'express'
    
    const health = new Health()
    const app = express()
    
    app.get('/healthz', createLivenessProbeListener(health))
    app.get('/readyz', createReadinessProbeListener(health))

    License

    MIT License, see LICENSE.

    Install

    npm i @k8ts/health

    DownloadsWeekly Downloads

    4

    Version

    0.1.1

    License

    MIT

    Unpacked Size

    35.8 kB

    Total Files

    19

    Last publish

    Collaborators

    • jacobwgillespie