Single Layer Solution: Health Check Configuration

Health Check is a feature that allows applications to monitor their health and diagnose potential issues. The single-layer solution template comes with pre-configured Health Check system.

In the single-layer solution template, Health Check configuration is applied in the following cases:

• When MVC is selected as the web application type.
• When Blazor Server is selected as the web application type.
• When Angular is selected as the web application type (configured at the backend).
• When No UI is selected as the web application type (configured at the backend).

Configuration in HealthChecksBuilderExtensions.cs

Health Checks are configured in the HealthChecksBuilderExtensions class. This class extends IServiceCollection to register health check services and configure health check UI endpoints.

Default Configuration

The default setup is as follows:

using HealthChecks.UI.Client;
using Microsoft.AspNetCore.Diagnostics.HealthChecks;

namespace MyCompanyName.MyProjectName.HealthChecks;

public static class HealthChecksBuilderExtensions
{
    public static void AddMyProjectNameHealthChecks(this IServiceCollection services)
    {
        // Add your health checks here
        var healthChecksBuilder = services.AddHealthChecks();
        healthChecksBuilder.AddCheck<MyProjectNameDatabaseCheck>("MyProjectName DbContext Check", tags: new string[] { "database" });

        // Read configuration for health check URL
        var configuration = services.GetConfiguration();
        var healthCheckUrl = configuration["App:HealthCheckUrl"] ?? "/health-status";
        
        services.ConfigureHealthCheckEndpoint(healthCheckUrl);

        // Configure HealthChecks UI
        var healthChecksUiBuilder = services.AddHealthChecksUI(settings =>
        {
            settings.AddHealthCheckEndpoint("MyProjectName Health Status", healthCheckUrl);
        });

        // Set HealthCheck UI storage
        healthChecksUiBuilder.AddInMemoryStorage();

        services.MapHealthChecksUiEndpoints(options =>
        {
            options.UIPath = "/health-ui";
            options.ApiPath = "/health-api";
        });
    }

    private static IServiceCollection ConfigureHealthCheckEndpoint(this IServiceCollection services, string path)
    {
       ....
    }

    private static IServiceCollection MapHealthChecksUiEndpoints(this IServiceCollection services, Action<global::HealthChecks.UI.Configuration.Options>? setupOption = null)
    {
       ....
    }
}

Database Health Check Implementation

The MyProjectNameDatabaseCheck class is a custom implementation of a health check that verifies database connectivity using IIdentityRoleRepository.

using System;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Diagnostics.HealthChecks;
using Volo.Abp.DependencyInjection;
using Volo.Abp.Identity;

namespace MyCompanyName.MyProjectName.HealthChecks;

public class MyProjectNameDatabaseCheck : IHealthCheck, ITransientDependency
{
    protected readonly IIdentityRoleRepository IdentityRoleRepository;

    public MyProjectNameDatabaseCheck(IIdentityRoleRepository identityRoleRepository)
    {
        IdentityRoleRepository = identityRoleRepository;
    }

    public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
    {
        try
        {
            await IdentityRoleRepository.GetListAsync(sorting: nameof(IdentityRole.Id), maxResultCount: 1, cancellationToken: cancellationToken);
            return HealthCheckResult.Healthy($"Could connect to database and get record.");
        }
        catch (Exception e)
        {
            return HealthCheckResult.Unhealthy($"Error when trying to get database record. ", e);
        }
    }
}