Atc.Rest.HealthChecks 4.1.0

Atc.Rest.HealthChecks

Target Framework: net10.0

Health check implementations and utilities for ASP.NET Core applications. Provides factories and helpers for creating JSON-formatted health check endpoints with detailed resource status information.

Why Use This Library?

Building robust health check endpoints requires consistent formatting and detailed status information. Atc.Rest.HealthChecks simplifies this by providing:

• JSON Health Check Responses: Factory methods for JSON-formatted health checks
• Resource Health Tracking: Track individual service/resource health status
• Detailed Diagnostics: Include timing, status, and error details for each check
• IReadOnlyDictionary Conversion: Helper extensions for health check data
• Production-Ready Endpoints: Standardized health check responses

Perfect for:

• Microservices requiring health endpoints
• Kubernetes/container orchestration health probes
• Load balancer health checks
• Monitoring and observability solutions
• API management platforms

Installation

dotnet add package Atc.Rest.HealthChecks

Target Framework

• .NET 10.0

Key Features

• HealthCheckOptionsFactory for creating JSON health check endpoints
• ResourceHealthCheck class for tracking individual resource status
• Extension methods for converting health data to IReadOnlyDictionary
• Integration with Microsoft.Extensions.Diagnostics.HealthChecks
• Support for custom health check implementations
• MetricsHealthCheckPublisher to publish health check status and duration as metrics

Publishing health checks as metrics

AddMetricsPublisher() publishes the latest result of every health check on the meter MetricsHealthCheckPublisher.MeterName ("Atc.Rest.HealthChecks"), tagged health_check.name:

• health_check.status: 0 = Unhealthy, 0.5 = Degraded, 1 = Healthy
• health_check.duration: seconds

services.Configure<HealthCheckPublisherOptions>(o =>
{
    o.Delay = TimeSpan.FromSeconds(5);
    o.Period = TimeSpan.FromSeconds(30);
});

services
    .AddHealthChecks()
    .AddCheck<MyHealthCheck>("my-check")
    .AddMetricsPublisher();

// e.g. with OpenTelemetry
services.AddOpenTelemetry().WithMetrics(m => m.AddMeter(MetricsHealthCheckPublisher.MeterName));

Requirements

• .NET 10

Key Dependencies

• Microsoft.AspNetCore.App (framework reference)
• Microsoft.Extensions.Diagnostics.HealthChecks (provided by Microsoft.AspNetCore.App)
• Atc (foundation library)

Code documentation

References

References extended

Examples

The Startup.cs class in an API

using Microsoft.Extensions.Diagnostics.HealthChecks;

public class Startup
{
    private readonly JsonSerializerOptions jsonSerializerOptions;

    public Startup()
    {
        jsonSerializerOptions = Atc.Serialization.JsonSerializerOptionsFactory.Create();
    }

    public void ConfigureServices(IServiceCollection services)
    {
        services
            .AddHealthChecks()
                .AddCheck<MyHealthCheck>(
                    name: "MyHealthCheck",
                    failureStatus: HealthStatus.Unhealthy,
                    timeout: TimeSpan.FromSeconds(30));
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapHealthChecks(
                "/health",
                HealthCheckOptionsFactory.CreateJson(
                    "ApplicationName.Api",
                    jsonSerializerOptions));
        });
    }
}

The MyHealthCheck class

public class MyHealthCheck : IHealthCheck
{
    public Task<HealthCheckResult> CheckHealthAsync(
        HealthCheckContext context,
        CancellationToken cancellationToken = default)
    {
        var data = new List<ResourceHealthCheck>();

        CheckSomeServices(data);

        if (data.All(x => x.Status == HealthStatus.Healthy))
        {
            return Task.FromResult(
                HealthCheckResult.Healthy(
                    "ApplicationName is healthy.",
                    data: data.ToIReadOnlyDictionary()));
        }

        return Task.FromResult(
            HealthCheckResult.Unhealthy(
                "ApplicationName is unhealthy.",
                exception: null,
                data: data.ToIReadOnlyDictionary()));
    }

    private void CheckSomeServices(
        ICollection<ResourceHealthCheck> data)
    {
        var sw = Stopwatch.StartNew();

        // Perform first HealthCheck and add a healthCheck to the data dictionary
        data.Add(
            new ResourceHealthCheck(
                "Service1",
                HealthStatus.Healthy,
                "Service1 is running.",
                sw.Elapsed));

        // Perform second HealthCheck and add a healthCheck to the data dictionary
        sw.Reset();
        data.Add(
            new ResourceHealthCheck(
                "Service2",
                HealthStatus.Unhealthy,
                "Service2 is not running.",
                sw.Elapsed));

        sw.Stop();
    }
}

Contributing

Contributions are welcome! Please see the main repository README for contribution guidelines.