Added healthchecks to server

docs/Server.md

@@ -3,7 +3,9 @@ The server by default
 - runs on port 5146
 - Uses Swagger UI in development mode (`/swagger/index.html`)
 - Ignores API keys when in development mode
-
+- Uses Elmah error logging (endpoint: `/elmah`, local files: `~/logs`)
+- Uses serilog logging (local files: `~/logs`)
+- Uses HealthChecks (endpoint: `/healthz`)
 # Installing the dependencies
 ## Ubuntu 24.04
 1. Install the .NET SDK: `sudo apt update && sudo apt install dotnet-sdk-8.0 -y`

src/Server/HealthChecks/AIProviderHealthChecks.cs

@@ -0,0 +1,31 @@
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using Server.Migrations;
+
+namespace Server.HealthChecks;
+
+public class AIProviderHealthCheck : IHealthCheck
+{
+    private readonly SearchdomainManager _searchdomainManager;
+    private readonly ILogger<DatabaseHealthCheck> _logger;
+    public AIProviderHealthCheck(SearchdomainManager searchdomainManager, ILogger<DatabaseHealthCheck> logger)
+    {
+        _searchdomainManager = searchdomainManager;
+        _logger = logger;
+    }
+    public Task<HealthCheckResult> CheckHealthAsync(
+        HealthCheckContext context, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var _ = _searchdomainManager.client.ListLocalModelsAsync(cancellationToken).Result;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogCritical("AIProviderHealthCheck - Exception occurred when listing local models: {ex}", ex.Message);
+            return Task.FromResult(
+                HealthCheckResult.Unhealthy());
+        }
+        return Task.FromResult(
+            HealthCheckResult.Healthy());
+    }
+}

src/Server/HealthChecks/ServerHealthChecks.cs

@@ -0,0 +1,44 @@
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using Server.Migrations;
+
+namespace Server.HealthChecks;
+
+public class DatabaseHealthCheck : IHealthCheck
+{
+    private readonly SearchdomainManager _searchdomainManager;
+    private readonly ILogger<DatabaseHealthCheck> _logger;
+    public DatabaseHealthCheck(SearchdomainManager searchdomainManager, ILogger<DatabaseHealthCheck> logger)
+    {
+        _searchdomainManager = searchdomainManager;
+        _logger = logger;
+    }
+    public Task<HealthCheckResult> CheckHealthAsync(
+        HealthCheckContext context, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            DatabaseMigrations.DatabaseGetVersion(_searchdomainManager.helper);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogCritical("DatabaseHealthCheck - Exception occurred when retrieving and parsing database version: {ex}", ex.Message);
+            return Task.FromResult(
+                HealthCheckResult.Unhealthy());
+        }
+
+        try
+        {
+            _searchdomainManager.helper.ExecuteSQLNonQuery("INSERT INTO settings (name, value) VALUES ('test', 'x');", []);
+            _searchdomainManager.helper.ExecuteSQLNonQuery("DELETE FROM settings WHERE name = 'test';", []);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogCritical("DatabaseHealthCheck - Exception occurred when executing INSERT/DELETE query: {ex}", ex.Message);
+            return Task.FromResult(
+                HealthCheckResult.Unhealthy());
+        }
+
+        return Task.FromResult(
+            HealthCheckResult.Healthy());
+    }
+}

src/Server/Program.cs

@@ -2,6 +2,7 @@ using ElmahCore;
 using ElmahCore.Mvc;
 using Serilog;
 using Server;
+using Server.HealthChecks;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -16,6 +17,9 @@ Log.Logger = new LoggerConfiguration()
     .CreateLogger();
 builder.Logging.AddSerilog();
 builder.Services.AddSingleton<SearchdomainManager>();
+builder.Services.AddHealthChecks()
+    .AddCheck<DatabaseHealthCheck>("DatabaseHealthCheck")
+    .AddCheck<AIProviderHealthCheck>("AIProviderHealthChecck");
 
 builder.Services.AddElmah<XmlFileErrorLog>(Options =>
 {
@@ -48,6 +52,8 @@ app.Use(async (context, next) =>
 
 app.UseElmah();
 
+app.MapHealthChecks("/healthz");
+
 // Configure the HTTP request pipeline.
 if (app.Environment.IsDevelopment())
 {