Top Locks command implementation (#7052)

API to list locks used in distributed XL mode

pkg/madmin/top-commands.go

@@ -0,0 +1,78 @@
+/*
+ * Minio Cloud Storage, (C) 2019 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package madmin
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"time"
+)
+
+// LockEntry holds information about client requesting the lock,
+// servers holding the lock, source on the client machine,
+// ID, type(read or write) and time stamp.
+type LockEntry struct {
+	Timestamp  time.Time `json:"time"`       // Timestamp set at the time of initialization.
+	Resource   string    `json:"resource"`   // Resource contains info like bucket, object etc
+	Type       string    `json:"type"`       // Bool whether write or read lock.
+	Source     string    `json:"source"`     // Source which created the lock
+	ServerList []string  `json:"serverlist"` // RPC path of servers issuing the lock.
+	Owner      string    `json:"owner"`      // RPC path of client claiming lock.
+	ID         string    `json:"id"`         // UID to uniquely identify request of client.
+}
+
+// LockEntries - To sort the locks
+type LockEntries []LockEntry
+
+func (l LockEntries) Len() int {
+	return len(l)
+}
+
+func (l LockEntries) Less(i, j int) bool {
+	return l[i].Timestamp.Before(l[j].Timestamp)
+}
+
+func (l LockEntries) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
+
+// TopLocks - returns the oldest locks in a minio setup.
+func (adm *AdminClient) TopLocks() (LockEntries, error) {
+	// Execute GET on /minio/admin/v1/top/locks
+	// to get the oldest locks in a minio setup.
+	resp, err := adm.executeMethod("GET",
+		requestData{relPath: "/v1/top/locks"})
+	defer closeResponse(resp)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, httpRespToErrorResponse(resp)
+	}
+
+	response, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return LockEntries{}, err
+	}
+
+	var lockEntries LockEntries
+	err = json.Unmarshal(response, &lockEntries)
+	return lockEntries, err
+}