Added MySQL HealthChecks Query and Callback support. (#1835)

src/HealthChecks.MySql/DependencyInjection/MySqlHealthCheckBuilderExtensions.cs

@@ -1,5 +1,6 @@
 using HealthChecks.MySql;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
+using MySqlConnector;
 
 namespace Microsoft.Extensions.DependencyInjection;
 
@@ -9,12 +10,15 @@ namespace Microsoft.Extensions.DependencyInjection;
 public static class MySqlHealthCheckBuilderExtensions
 {
     private const string NAME = "mysql";
+    internal const string HEALTH_QUERY = "SELECT 1;";
 
     /// <summary>
-    /// Add a health check for MySql databases.
+    /// Add a health check for MySQL databases.
     /// </summary>
     /// <param name="builder">The <see cref="IHealthChecksBuilder"/>.</param>
-    /// <param name="connectionString">The MySql connection string to be used.</param>
+    /// <param name="connectionString">The MySQL connection string to be used.</param>
+    /// <param name="healthQuery">The query to be executed.</param>
+    /// <param name="configure">An optional action to allow additional MySQL specific configuration.</param>
     /// <param name="name">The health check name. Optional. If <c>null</c> the type name 'mysql' will be used for the name.</param>
     /// <param name="failureStatus">
     /// The <see cref="HealthStatus"/> that should be reported when the health check fails. Optional. If <c>null</c> then
@@ -26,14 +30,86 @@ public static class MySqlHealthCheckBuilderExtensions
     public static IHealthChecksBuilder AddMySql(
         this IHealthChecksBuilder builder,
         string connectionString,
+        string healthQuery = HEALTH_QUERY,
+        Action<MySqlConnection>? configure = null,
         string? name = default,
         HealthStatus? failureStatus = default,
         IEnumerable<string>? tags = default,
         TimeSpan? timeout = default)
     {
+        return builder.AddMySql(_ => connectionString, healthQuery, configure, name, failureStatus, tags, timeout);
+    }
+
+    /// <summary>
+    /// Add a health check for MySQL databases.
+    /// </summary>
+    /// <param name="builder">The <see cref="IHealthChecksBuilder"/>.</param>
+    /// <param name="connectionStringFactory">A factory to build the MySQL connection string to use.</param>
+    /// <param name="healthQuery">The query to be executed.</param>
+    /// <param name="configure">An optional action to allow additional MySQL specific configuration.</param>
+    /// <param name="name">The health check name. Optional. If <c>null</c> the type name 'mysql' will be used for the name.</param>
+    /// <param name="failureStatus">
+    /// The <see cref="HealthStatus"/> that should be reported when the health check fails. Optional. If <c>null</c> then
+    /// the default status of <see cref="HealthStatus.Unhealthy"/> will be reported.
+    /// </param>
+    /// <param name="tags">A list of tags that can be used to filter sets of health checks. Optional.</param>
+    /// <param name="timeout">An optional <see cref="TimeSpan"/> representing the timeout of the check.</param>
+    /// <returns>The specified <paramref name="builder"/>.</returns>
+    public static IHealthChecksBuilder AddMySql(
+        this IHealthChecksBuilder builder,
+        Func<IServiceProvider, string> connectionStringFactory,
+        string healthQuery = HEALTH_QUERY,
+        Action<MySqlConnection>? configure = null,
+        string? name = default,
+        HealthStatus? failureStatus = default,
+        IEnumerable<string>? tags = default,
+        TimeSpan? timeout = default)
+    {
+        Guard.ThrowIfNull(connectionStringFactory);
+
+        return builder.Add(new HealthCheckRegistration(
+            name ?? NAME,
+            sp =>
+            {
+                var options = new MySqlHealthCheckOptions
+                {
+                    ConnectionString = connectionStringFactory(sp),
+                    CommandText = healthQuery,
+                    Configure = configure,
+                };
+                return new MySqlHealthCheck(options);
+            },
+            failureStatus,
+            tags,
+            timeout));
+    }
+
+    /// <summary>
+    /// Add a health check for MySQL databases.
+    /// </summary>
+    /// <param name="builder">The <see cref="IHealthChecksBuilder"/>.</param>
+    /// <param name="options">Options for health check.</param>
+    /// <param name="name">The health check name. Optional. If <c>null</c> the type name 'mysql' will be used for the name.</param>
+    /// <param name="failureStatus">
+    /// The <see cref="HealthStatus"/> that should be reported when the health check fails. Optional. If <c>null</c> then
+    /// the default status of <see cref="HealthStatus.Unhealthy"/> will be reported.
+    /// </param>
+    /// <param name="tags">A list of tags that can be used to filter sets of health checks. Optional.</param>
+    /// <param name="timeout">An optional <see cref="TimeSpan"/> representing the timeout of the check.</param>
+    /// <returns>The specified <paramref name="builder"/>.</returns>
+    public static IHealthChecksBuilder AddMySql(
+        this IHealthChecksBuilder builder,
+        MySqlHealthCheckOptions options,
+        string? name = default,
+        HealthStatus? failureStatus = default,
+        IEnumerable<string>? tags = default,
+        TimeSpan? timeout = default)
+    {
+        Guard.ThrowIfNull(options);
+
         return builder.Add(new HealthCheckRegistration(
             name ?? NAME,
-            _ => new MySqlHealthCheck(connectionString),
+            _ => new MySqlHealthCheck(options),
             failureStatus,
             tags,
             timeout));

src/HealthChecks.MySql/MySqlHealthCheck.cs

@@ -8,25 +8,32 @@ namespace HealthChecks.MySql;
 /// </summary>
 public class MySqlHealthCheck : IHealthCheck
 {
-    private readonly string _connectionString;
+    private readonly MySqlHealthCheckOptions _options;
 
-    public MySqlHealthCheck(string connectionString)
+    public MySqlHealthCheck(MySqlHealthCheckOptions options)
     {
-        _connectionString = Guard.ThrowIfNull(connectionString);
+        Guard.ThrowIfNull(options.ConnectionString, true);
+        Guard.ThrowIfNull(options.CommandText, true);
+        _options = options;
     }
 
     /// <inheritdoc />
     public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
     {
         try
         {
-            using var connection = new MySqlConnection(_connectionString);
+            using var connection = new MySqlConnection(_options.ConnectionString);
 
+            _options.Configure?.Invoke(connection);
             await connection.OpenAsync(cancellationToken).ConfigureAwait(false);
 
-            return await connection.PingAsync(cancellationToken).ConfigureAwait(false)
+            using var command = connection.CreateCommand();
+            command.CommandText = _options.CommandText;
+            object? result = await command.ExecuteScalarAsync(cancellationToken).ConfigureAwait(false);
+
+            return _options.HealthCheckResultBuilder == null
                 ? HealthCheckResult.Healthy()
-                : new HealthCheckResult(context.Registration.FailureStatus, description: $"The {nameof(MySqlHealthCheck)} check fail.");
+                : _options.HealthCheckResultBuilder(result);
         }
         catch (Exception ex)
         {

src/HealthChecks.MySql/MySqlHealthCheckOptions.cs

@@ -0,0 +1,31 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using MySqlConnector;
+
+namespace HealthChecks.MySql;
+
+/// <summary>
+/// Options for <see cref="MySqlHealthCheck"/>.
+/// </summary>
+public class MySqlHealthCheckOptions
+{
+    /// <summary>
+    /// The MySQL connection string to be used.
+    /// </summary>
+    public string ConnectionString { get; set; } = null!;
+
+    /// <summary>
+    /// The query to be executed.
+    /// </summary>
+    public string CommandText { get; set; } = MySqlHealthCheckBuilderExtensions.HEALTH_QUERY;
+
+    /// <summary>
+    /// An optional action executed before the connection is opened in the health check.
+    /// </summary>
+    public Action<MySqlConnection>? Configure { get; set; }
+
+    /// <summary>
+    /// An optional delegate to build health check result.
+    /// </summary>
+    public Func<object?, HealthCheckResult>? HealthCheckResultBuilder { get; set; }
+}

test/HealthChecks.MySql.Tests/Functional/MySqlHealthCheckTests.cs

@@ -55,4 +55,34 @@ public async Task be_unhealthy_when_mysql_server_is_unavailable()
 
         response.StatusCode.ShouldBe(HttpStatusCode.ServiceUnavailable);
     }
+
+    [Fact]
+    public async Task be_unhealthy_when_mysql_server_is_unavailable_using_options()
+    {
+        var connectionString = "server=255.255.255.255;port=3306;database=information_schema;uid=root;password=Password12!";
+
+        var webHostBuilder = new WebHostBuilder()
+            .ConfigureServices(services =>
+            {
+                var mysqlOptions = new MySqlHealthCheckOptions
+                {
+                    ConnectionString = connectionString
+                };
+                services.AddHealthChecks()
+                    .AddMySql(mysqlOptions, tags: new string[] { "mysql" });
+            })
+            .Configure(app =>
+            {
+                app.UseHealthChecks("/health", new HealthCheckOptions
+                {
+                    Predicate = r => r.Tags.Contains("mysql")
+                });
+            });
+
+        using var server = new TestServer(webHostBuilder);
+
+        var response = await server.CreateRequest("/health").GetAsync().ConfigureAwait(false);
+
+        response.StatusCode.ShouldBe(HttpStatusCode.ServiceUnavailable);
+    }
 }

test/HealthChecks.MySql.Tests/HealthChecks.MySql.approved.txt

@@ -2,14 +2,24 @@ namespace HealthChecks.MySql
 {
     public class MySqlHealthCheck : Microsoft.Extensions.Diagnostics.HealthChecks.IHealthCheck
     {
-        public MySqlHealthCheck(string connectionString) { }
+        public MySqlHealthCheck(HealthChecks.MySql.MySqlHealthCheckOptions options) { }
         public System.Threading.Tasks.Task<Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckResult> CheckHealthAsync(Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckContext context, System.Threading.CancellationToken cancellationToken = default) { }
     }
+    public class MySqlHealthCheckOptions
+    {
+        public MySqlHealthCheckOptions() { }
+        public string CommandText { get; set; }
+        public System.Action<MySqlConnector.MySqlConnection>? Configure { get; set; }
+        public string ConnectionString { get; set; }
+        public System.Func<object?, Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckResult>? HealthCheckResultBuilder { get; set; }
+    }
 }
 namespace Microsoft.Extensions.DependencyInjection
 {
     public static class MySqlHealthCheckBuilderExtensions
     {
-        public static Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder AddMySql(this Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder builder, string connectionString, string? name = null, Microsoft.Extensions.Diagnostics.HealthChecks.HealthStatus? failureStatus = default, System.Collections.Generic.IEnumerable<string>? tags = null, System.TimeSpan? timeout = default) { }
+        public static Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder AddMySql(this Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder builder, HealthChecks.MySql.MySqlHealthCheckOptions options, string? name = null, Microsoft.Extensions.Diagnostics.HealthChecks.HealthStatus? failureStatus = default, System.Collections.Generic.IEnumerable<string>? tags = null, System.TimeSpan? timeout = default) { }
+        public static Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder AddMySql(this Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder builder, System.Func<System.IServiceProvider, string> connectionStringFactory, string healthQuery = "SELECT 1;", System.Action<MySqlConnector.MySqlConnection>? configure = null, string? name = null, Microsoft.Extensions.Diagnostics.HealthChecks.HealthStatus? failureStatus = default, System.Collections.Generic.IEnumerable<string>? tags = null, System.TimeSpan? timeout = default) { }
+        public static Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder AddMySql(this Microsoft.Extensions.DependencyInjection.IHealthChecksBuilder builder, string connectionString, string healthQuery = "SELECT 1;", System.Action<MySqlConnector.MySqlConnection>? configure = null, string? name = null, Microsoft.Extensions.Diagnostics.HealthChecks.HealthStatus? failureStatus = default, System.Collections.Generic.IEnumerable<string>? tags = null, System.TimeSpan? timeout = default) { }
     }
 }