Project

HealtRegistry/Containerfile

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+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build-env
+WORKDIR /build
+
+# Copy everything
+COPY . ./
+# Restore as distinct layers
+RUN dotnet restore
+# Build and publish a release
+RUN dotnet publish -c Release -o out
+
+# Build runtime image
+FROM mcr.microsoft.com/dotnet/aspnet:8.0
+WORKDIR /app
+COPY --from=build-env /build/out .
+ENTRYPOINT ["dotnet", "HealtRegistry.dll"]

HealtRegistry/HealtRegistry.csproj

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+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <InvariantGlobalization>true</InvariantGlobalization>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
+  </ItemGroup>
+
+</Project>

HealtRegistry/HealtRegistry.http

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+### Send health pdate for service 'test'
+POST http://127.0.0.1:5081/health/test HTTP/1.0
+
+### Set health of service 'test' to unhealthy
+PUT http://127.0.0.1:5081/health/test HTTP/1.0
+Content-Type: application/json
+
+{
+    "health": false
+}
+
+### Set health of service 'test' to unhealthy
+PUT https://healthr.adix.link/health/doorbell HTTP/1.0
+Content-Type: application/json
+
+{
+    "health": false
+}

HealtRegistry/Models/HealthRequest.cs

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+namespace HealtRegistry.Models;
+
+public record HealthRequest(bool? Health);

HealtRegistry/Models/ServiceConfiguration.cs

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+namespace HealtRegistry.Models;
+
+public record ServiceConfiguration(bool DefaultValue, TimeSpan Timeout);

HealtRegistry/Models/ServiceHealthData.cs

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+namespace HealtRegistry.Models;
+
+public class ServiceHealthData
+{
+    public required bool Healthy { get; set; }
+    public required DateTimeOffset LastUpdated { get; set; }
+}

HealtRegistry/Models/ServiceHealthes.cs

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+namespace HealtRegistry.Models;
+
+public record ServiceHealth(bool Health);
+public record ServiceHealthes(IReadOnlyDictionary<string, ServiceHealth> Healthes);

HealtRegistry/Models/ServicesConfiguration.cs

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+using System.ComponentModel.DataAnnotations;
+
+namespace HealtRegistry.Models;
+
+public class ServicesConfiguration
+{
+    [Required] public required Dictionary<string, ServiceConfiguration> Services { get; init; }
+}

HealtRegistry/Program.cs

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+using HealtRegistry.Models;
+using HealtRegistry.Services;
+using Microsoft.AspNetCore.Mvc;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen();
+
+builder.Services.AddSingleton<IHealthService, HealthService>();
+
+builder.Services.AddHostedService<HealthTimeoutService>();
+
+builder.Services.AddOptions<ServicesConfiguration>()
+    .Bind(builder.Configuration)
+    .ValidateDataAnnotations();
+
+if (builder.Environment.IsProduction())
+{
+    builder.Configuration.AddJsonFile("/config/appsettings.json", optional: true, reloadOnChange: true);
+}
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+if (app.Environment.IsDevelopment())
+{
+    app.UseSwagger();
+    app.UseSwaggerUI();
+}
+
+app.MapPost("/health/{service}", ([FromRoute] string service, IHealthService healthService) =>
+{
+    healthService.SetServiceHealth(service, true);
+    return Results.Ok();
+})
+.WithOpenApi();
+
+app.MapPut("/health/{service}", ([FromRoute] string service, [FromBody] HealthRequest requestBody, IHealthService healthService, [FromServices] ILoggerFactory loggerFactory) =>
+{
+    if (requestBody.Health.HasValue)
+    {
+        healthService.SetServiceHealth(service, requestBody.Health.Value);
+    }
+    else
+    {
+        var logger = loggerFactory.CreateLogger("Health");
+        logger.LogDebug("Health request body does not contains 'Health' property");
+    }
+    return Results.Ok();
+})
+.WithOpenApi();
+
+app.MapGet("/status", (IHealthService healthService) =>
+{
+    return healthService.GetServiceHealthes();
+})
+.WithOpenApi();
+
+app.Run();

HealtRegistry/Properties/launchSettings.json

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+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:48758",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": false,
+      "launchUrl": "swagger",
+      "applicationUrl": "http://localhost:5081",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": false,
+      "launchUrl": "swagger",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

HealtRegistry/Services/HealthService.cs

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+using HealtRegistry.Models;
+using Microsoft.Extensions.Options;
+
+namespace HealtRegistry.Services;
+
+public class HealthService : IHealthService
+{
+
+    public Dictionary<string, ServiceHealthData> ServiceHealthes { get; } = new();
+
+    public HealthService(IOptions<ServicesConfiguration> servicesConfiguration)
+    {
+        foreach (var service in servicesConfiguration.Value.Services)
+        {
+            ServiceHealthes.Add(service.Key, new ServiceHealthData()
+            {
+                Healthy = service.Value.DefaultValue, 
+                LastUpdated = DateTimeOffset.Now
+            });
+        }
+    }
+
+    public ServiceHealthes GetServiceHealthes()
+    {
+        var serviceHealthes = ServiceHealthes.ToDictionary(x => x.Key, x => new ServiceHealth(x.Value.Healthy));
+        return new ServiceHealthes(serviceHealthes);
+    }
+
+    public void SetServiceHealth(string serviceName, bool health)
+    {
+        ServiceHealthes[serviceName].Healthy = health;
+        ServiceHealthes[serviceName].LastUpdated = DateTimeOffset.Now;
+    }
+}

HealtRegistry/Services/HealthTimeoutService.cs

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+
+using HealtRegistry.Models;
+using Microsoft.Extensions.Options;
+
+namespace HealtRegistry.Services;
+
+public class HealthTimeoutService : BackgroundService
+{
+    private readonly IHealthService _healthService;
+    private readonly IOptionsMonitor<ServicesConfiguration> _servicesConfiguration;
+    private readonly ILogger<HealthTimeoutService> _logger;
+
+    public HealthTimeoutService(
+        IHealthService healthService,
+        IOptionsMonitor<ServicesConfiguration> servicesConfiguration,
+        ILogger<HealthTimeoutService> logger
+    )
+    {
+        _healthService = healthService;
+        _servicesConfiguration = servicesConfiguration;
+        _logger = logger;
+    }
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            var now = DateTimeOffset.Now;
+            foreach (var service in _healthService.ServiceHealthes)
+            {
+                if (!service.Value.Healthy) continue;
+
+                var serviceConfiguration = _servicesConfiguration.CurrentValue.Services.TryGetValue(service.Key, out var configuration)
+                    ? configuration
+                    : null;
+
+                if (serviceConfiguration is not null &&
+                    now - service.Value.LastUpdated > serviceConfiguration.Timeout)
+                {
+                    _logger.LogInformation("Service {ServiceName} is timed out", service.Key);
+                    _healthService.SetServiceHealth(service.Key, false);
+                }
+            }
+
+            try
+            {
+                await Task.Delay(1000, stoppingToken);
+            }
+            catch { }
+        }
+    }
+}

HealtRegistry/Services/IHealthService.cs

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+using HealtRegistry.Models;
+
+namespace HealtRegistry.Services;
+
+public interface IHealthService
+{
+    Dictionary<string, ServiceHealthData> ServiceHealthes { get; }
+    ServiceHealthes GetServiceHealthes();
+    void SetServiceHealth(string serviceName, bool health);
+}

HealtRegistry/appsettings.Development.json

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+{
+  "Services": {
+    "test": {
+      "DefaultValue": false,
+      "Timeout": "00:00:30"
+    }
+  },
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

HealtRegistry/appsettings.json

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+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}