Change health check to test if a single bucket exists (#72)

* Add Rider-specific files to the .gitignore

* Change health check to test if a single bucket with a customizable name exists ('health' by default) instead of listing all buckets

.gitignore

@@ -23,6 +23,9 @@ bld/
 [Bb]in/
 [Oo]bj/
 
+# IDE-specific files (Rider)
+.idea
+
 # Visual Studio 2015 cache/options directory
 .vs/
 .vscode/

src/Minio.AspNetCore.HealthChecks/MinioHealthCheck.cs

@@ -1,14 +1,17 @@
 using Microsoft.Extensions.Diagnostics.HealthChecks;
+using Minio.DataModel.Args;
 
 namespace Minio.AspNetCore.HealthChecks
 {
   public class MinioHealthCheck : IHealthCheck
   {
     private readonly MinioClient minioClient;
+    private readonly string bucket;
 
-    public MinioHealthCheck(MinioClient minioClient)
+    public MinioHealthCheck(MinioClient minioClient, string bucket)
     {
       this.minioClient = minioClient;
+      this.bucket = bucket;
     }
 
     public async Task<HealthCheckResult> CheckHealthAsync(
@@ -17,7 +20,8 @@ public async Task<HealthCheckResult> CheckHealthAsync(
     {
       try
       {
-        await minioClient.ListBucketsAsync(cancellationToken).ConfigureAwait(false);
+        var bucketExistsArgs = new BucketExistsArgs().WithBucket(bucket);
+        await minioClient.BucketExistsAsync(bucketExistsArgs, cancellationToken).ConfigureAwait(false);
 
         return HealthCheckResult.Healthy();
       }

src/Minio.AspNetCore.HealthChecks/MinioHealthChecksExtensions.cs

@@ -5,10 +5,16 @@ namespace Minio.AspNetCore.HealthChecks
 {
   public static class MinioHealthChecksExtensions
   {
+    /// <summary>
+    /// Adds a health check for MinIO to the specified <see cref="builder"/>.
+    /// The health check tests if a bucket with the specified <see cref="bucket"/> name exists.
+    /// Whether the bucket actually exists doesn't matter - the health check is successful if the call to MinIO doesn't throw.
+    /// </summary>
     public static IHealthChecksBuilder AddMinio(
       this IHealthChecksBuilder builder,
       Func<IServiceProvider, MinioClient> factory,
       string name = "minio",
+      string bucket = "health",
       HealthStatus? failureStatus = null,
       IEnumerable<string>? tags = null,
       TimeSpan? timeout = null)
@@ -17,10 +23,18 @@ public static IHealthChecksBuilder AddMinio(
       {
         throw new ArgumentNullException(nameof(builder));
       }
+      if (string.IsNullOrWhiteSpace(name))
+      {
+        throw new ArgumentException("Health check name should not be null or whitespace.", nameof(name));
+      }
+      if (string.IsNullOrWhiteSpace(bucket))
+      {
+        throw new ArgumentException("Health check bucket should not be null or whitespace.", nameof(bucket));
+      }
 
       return builder.Add(new HealthCheckRegistration(
         name,
-        sp => new MinioHealthCheck(factory.Invoke(sp)),
+        sp => new MinioHealthCheck(factory.Invoke(sp), bucket),
         failureStatus,
         tags,
         timeout));