Use custom database healthcheck (#8973)

Jellyfin.Server/HealthChecks/DbContextFactoryHealthCheck.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+
+namespace Jellyfin.Server.HealthChecks;
+
+/// <summary>
+/// Implementation of the <see cref="DbContextHealthCheck{TContext}"/> for a <see cref="IDbContextFactory{TContext}"/>.
+/// </summary>
+/// <typeparam name="TContext">The type of database context.</typeparam>
+public class DbContextFactoryHealthCheck<TContext> : IHealthCheck
+    where TContext : DbContext
+{
+    private readonly IDbContextFactory<TContext> _dbContextFactory;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DbContextFactoryHealthCheck{TContext}"/> class.
+    /// </summary>
+    /// <param name="contextFactory">Instance of the <see cref="IDbContextFactory{TContext}"/> interface.</param>
+    public DbContextFactoryHealthCheck(IDbContextFactory<TContext> contextFactory)
+    {
+        _dbContextFactory = contextFactory;
+    }
+
+    /// <inheritdoc />
+    public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(context);
+
+        var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+        await using (dbContext.ConfigureAwait(false))
+        {
+            if (await dbContext.Database.CanConnectAsync(cancellationToken).ConfigureAwait(false))
+            {
+                return HealthCheckResult.Healthy();
+            }
+        }
+
+        return HealthCheckResult.Unhealthy();
+    }
+}

Jellyfin.Server/Startup.cs

@@ -8,6 +8,7 @@ using System.Text;
 using Jellyfin.MediaEncoding.Hls.Extensions;
 using Jellyfin.Networking.Configuration;
 using Jellyfin.Server.Extensions;
+using Jellyfin.Server.HealthChecks;
 using Jellyfin.Server.Implementations;
 using Jellyfin.Server.Implementations.Extensions;
 using Jellyfin.Server.Infrastructure;
@@ -122,7 +123,7 @@ namespace Jellyfin.Server
                 .ConfigurePrimaryHttpMessageHandler(defaultHttpClientHandlerDelegate);
 
             services.AddHealthChecks()
-                .AddDbContextCheck<JellyfinDb>();
+                .AddCheck<DbContextFactoryHealthCheck<JellyfinDb>>(nameof(JellyfinDb));
 
             services.AddHlsPlaylistGenerator();
         }