Implementing health checks in minimal APIs

Ilias el Matani

Introduction

As part of a recent backend project, I was tasked with implementing an essential feature: health checks. These checks are not just a mere addition; they are pivotal in maintaining the robustness of our API, especially considering the minimalist approach we've adopted.

Why health checks

Health checks are vital for:

  • Monitoring the API’s operational status.
  • Identifying issues early, before they impact users.
  • Facilitating load balancing and improving uptime.

Setting up health checks in a minimal API

Minimal APIs, introduced in .NET 6, simplify the process of setting up web services. Here’s how you can add health checks to your minimal API:

Install Necessary Packages

First, ensure that you have the Microsoft.AspNetCore.Diagnostics.HealthChecks package installed.

Configure Services

In your Program.cs, add the health check services:

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddHealthChecks();

Define Health Check Endpoints

Define a route for your health check:

var app = builder.Build();
app.MapHealthChecks("/health");

This endpoint will be used to monitor the health status of your API.

Advanced Health Check Configuration

For more complex scenarios, you can configure custom health checks:

  • Database health check: To monitor the status of a database connection.
  • Custom health check: Create your own health check logic for specific components.

Sample code for a custom health check

Here’s a simple example of a custom health check:

public class CustomHealthCheck : IHealthCheck
{
    public Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
    {
        // Your custom health check logic
        bool healthCheckSuccess = true;
        return healthCheckSuccess ? Task.FromResult(HealthCheckResult.Healthy("API is healthy.")) : Task.FromResult(HealthCheckResult.Unhealthy("API is unhealthy."));
    }
}

Best practices

  • Regularly update your health check logic to reflect changes in your API.
  • Monitor the health check endpoint using automated tools.
  • Consider security aspects when exposing health check information.

Conclusion

Implementing health checks in minimal API is a straightforward yet effective way to ensure your application's health and reliability.