README.md

HealthChecks

This repository is dedicated to providing custom implementations of IHealthCheck for .NET applications, offering additional health monitoring capabilities beyond the default checks.

Features

• Uptime Health Check: Monitor the uptime of your application, adding startup time and uptime information to your health reports.

Getting Started

Prerequisites

• .NET SDK ≥ 8.0.2
• Microsoft.Extensions.Diagnostics.HealthChecks ≥ 8.0.7
• An existing .NET application to integrate the health checks into

Installation

You can add the Uptime Health Check to your project via NuGet:

dotnet add package HealthChecks.Uptime

Configuration

Adding to your services:

In your Startup.cs or wherever you configure services, add the uptime health check:

using HealthChecks.Uptime;

public void ConfigureServices(IServiceCollection services)
{
    // Your existing service configurations

    services.AddHealthChecks()
        .AddUptimeHealthCheck();
}

NEW - HealthChecks now supports setting a degraded service threshold.

By setting a threshold, the healthcheck status will return degraded until the configured amount of time in seconds has passed.

using HealthChecks.Uptime;

public void ConfigureServices(IServiceCollection services)
{
    // Your existing service configurations

    services.AddHealthChecks()
        .AddUptimeHealthCheck((options) => {
            options.DegradedThresholdInSeconds = 120;
        });
}

Setting up the endpoint (optional)

Configure the health check endpoint in your application's request pipeline:

app.UseHealthChecks("/_health", new HealthCheckOptions
{
    ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse,
    AllowCachingResponses = false
});

Tip

Add the AspNetCore.HealthChecks.UI.Client package to make use of the UIResponseWriter class and give the Status property a user-friendly translation to text.

Running the Health Check Report Manually

You can create the Health Check report manually by getting an instance of the HealthCheckService and calling CheckHealthAsyn() as below;

// Where _provider is a local DI instance of `IServiceProvider`.
var healthCheckService = _provider.GetService<HealthCheckService>();

if (healthCheckService == null)
{
    // Optionally, return a meaningful response or handle the logic as required
    return JsonSerializer.Serialize(new { Error = "HealthCheckService is not available." });
}

var response = await healthCheckService.CheckHealthAsync();

var options = new JsonSerializerOptions
{
    WriteIndented = true, // For pretty-printing. Set to false in production for compact JSON.
    PropertyNamingPolicy = JsonNamingPolicy.CamelCase, // Common convention for JSON property names.
    IgnoreNullValues = true // Optional: depending on whether you want to include properties with null values.
};

string jsonReport = JsonSerializer.Serialize(response, options);

Sample Output

The below JSON sample is representative of the output from both the manual report and from endpoint.

{
    "status": "Healthy",
    "totalDuration": "00:00:00.0000202",
    "entries": {
        "startup_time": {
            "data": {
                "Startup Time": "2024-02-27T09:41:49.7002848+00:00",
                "Uptime": "08:23:57.5520239"
            },
            "description": "Application has been running without issues.",
            "duration": "00:00:00.0000202",
            "status": "Healthy",
            "tags": []
        }
    }
}