Verify that remote target bucket is on MinIO server for bucket replication (#18656)

cmd/bucket-targets.go

@@ -19,6 +19,7 @@ package cmd
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/url"
 	"sync"
@@ -351,6 +352,27 @@ func (sys *BucketTargetSys) SetTarget(ctx context.Context, bucket string, tgt *m
 			return BucketRemoteTargetNotVersioned{Bucket: tgt.TargetBucket}
 		}
 	}
+
+	// Check if target is a MinIO server and alive
+	hcCtx, cancel := context.WithTimeout(ctx, 3*time.Second)
+	scheme := "http"
+	if tgt.Secure {
+		scheme = "https"
+	}
+	result := <-sys.hcClient.Alive(hcCtx, madmin.AliveOpts{}, madmin.ServerProperties{
+		Endpoint: tgt.Endpoint,
+		Scheme:   scheme,
+	})
+
+	cancel()
+	if result.Error != nil {
+		return RemoteTargetConnectionErr{Bucket: tgt.TargetBucket, Err: result.Error, AccessKey: tgt.Credentials.AccessKey}
+	}
+	if !result.Online {
+		err := errors.New("Health check timed out after 3 seconds")
+		return RemoteTargetConnectionErr{Err: err}
+	}
+
 	sys.Lock()
 	defer sys.Unlock()