Overview

This package aims to provide report output similar to the AspNetCore.Diagnostics.HealthChecks package in NuGet.

Note This package is currently minimally configured to support HealthReport and UIHealthReport output of AspNetCore.Diagnostics.HealthChecks 6.*. Therefore, for other use cases such as integrating it into routing, you will need to implement it individually for each framework.

Motivation

When operating containerized applications, configuring health checks becomes essential. Health checks are supported in various operational environments, and while the HTTP status code rules are generally consistent, the payload schema can vary depending on the environment.

In my own experience, I frequently develop APIs using ASP.NET, and in such cases, I typically combine AspNetCore.Diagnostics.HealthChecks with HealthChecksUI for configuring and monitoring health checks.

As I have been working more with Node.js recently, I decided to develop this package to enable handling the output of AspNetCore.Diagnostics.HealthChecks in Node.js.

graph LR
    node1["Node.js Project\n(Wants to export UIHealthReport!)"]
    node2["ASP.NET Project\n(Exports UIHealthReport)"]
    node3["HealthChecks UI ASP.NET Project\n(Collects UIHealthReport)"]

    node3-->node1
    node3-->node2

Installation

npm install @appsightnet/nodejs-aspnet-healthz

Usage

// Create HealthCheckService instance
const options: HealthCheckServiceOptions = {
  registrations: [
    {
      name: 'healthy-0',
      instance: new StubHealthCheck('Healthy'),
      tags: ['liveness'],
    },
  ],
}
const healthCheckService = new DefaultHealthCheckService(options)

// Perform checks
const healthReport = await healthCheckService.checkHealthAsync()

// Export UIHealthReport json
const uiHealthReport = UIHealthReportUtils.fromHealthReport(healthReport)
console.log(JSON.stringify(uiHealthReport))

{
  "status": "Healthy",
  "totalDuration": "00:00:00.000",
  "entries": {
    "healthy-0": {
      "status": "Healthy",
      "description": "healthy-0 is Healthy!",
      "duration": "00:00:00.000",
      "tags": ["liveness"]
    }
  }
}

API Reference

• Docs

Options

Perform only readiness checks

const healthReport = await healthCheckService.checkHealthAsync((predicate) =>
  predicate.tags.includes('readiness')
)

Set timeout per registration

const options: HealthCheckServiceOptions = {
  registrations: [
    {
      name: 'healthy-0',
      instance: new StubHealthCheck('Healthy'),
      tags: ['liveness'],
      timeoutMilliseconds: 1000,
    },
    {
      name: 'healthy-1',
      instance: new StubHealthCheck('Healthy'),
      tags: ['liveness'],
      timeoutMilliseconds: 2000,
    },
  ],
}
const healthCheckService = new DefaultHealthCheckService(options)

Set overall timeout for checks

const healthReport = await healthCheckService.checkHealthAsync(
  (_) => true,
  30000 // 30 seconds
)

Change Log

TBD

Acknowledgements

• Special thanks to all contributors to AspNetCore.Diagnostics.HealthChecks, which served as a valuable reference for this project.