Merge pull request #1345 from yue9944882/lease-lock

Feat: Adding lease lock implementation

Author: k8s-ci-robot

extended/src/main/java/io/kubernetes/client/extended/leaderelection/resourcelock/LeaseLock.java

@@ -0,0 +1,137 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+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 io.kubernetes.client.extended.leaderelection.resourcelock;
+
+import io.kubernetes.client.extended.leaderelection.LeaderElectionRecord;
+import io.kubernetes.client.extended.leaderelection.Lock;
+import io.kubernetes.client.openapi.ApiClient;
+import io.kubernetes.client.openapi.ApiException;
+import io.kubernetes.client.openapi.Configuration;
+import io.kubernetes.client.openapi.apis.CoordinationV1Api;
+import io.kubernetes.client.openapi.models.V1Lease;
+import io.kubernetes.client.openapi.models.V1LeaseSpec;
+import io.kubernetes.client.openapi.models.V1ObjectMeta;
+import java.net.HttpURLConnection;
+import java.util.concurrent.atomic.AtomicReference;
+import org.joda.time.DateTime;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class LeaseLock implements Lock {
+
+  private static final Logger log = LoggerFactory.getLogger(LeaseLock.class);
+
+  // Namespace and name describes the endpoint object
+  // that the LeaderElector will attempt to lead.
+  private final String namespace;
+  private final String name;
+  private final String identity;
+
+  private CoordinationV1Api coordinationV1Api;
+
+  private AtomicReference<V1Lease> leaseRefer = new AtomicReference<>(null);
+
+  public LeaseLock(String namespace, String name, String identity) {
+    this(namespace, name, identity, Configuration.getDefaultApiClient());
+  }
+
+  public LeaseLock(String namespace, String name, String identity, ApiClient apiClient) {
+    this.namespace = namespace;
+    this.name = name;
+    this.identity = identity;
+    this.coordinationV1Api = new CoordinationV1Api(apiClient);
+  }
+
+  @Override
+  public LeaderElectionRecord get() throws ApiException {
+    V1Lease lease = coordinationV1Api.readNamespacedLease(name, namespace, null, null, null);
+    leaseRefer.set(lease);
+    return getRecordFromLease(lease.getSpec());
+  }
+
+  @Override
+  public boolean create(LeaderElectionRecord record) {
+    try {
+      V1Lease createdLease =
+          coordinationV1Api.createNamespacedLease(
+              namespace,
+              new V1Lease()
+                  .metadata(new V1ObjectMeta().namespace(namespace).name(name))
+                  .spec(getLeaseFromRecord(record)),
+              null,
+              null,
+              null);
+      leaseRefer.set(createdLease);
+      return true;
+    } catch (ApiException e) {
+      if (e.getCode() == HttpURLConnection.HTTP_CONFLICT) {
+        log.debug("received {} when creating configmap lock", e.getCode(), e);
+      } else {
+        log.error("received {} when creating configmap lock", e.getCode(), e);
+      }
+      return false;
+    }
+  }
+
+  @Override
+  public boolean update(LeaderElectionRecord record) {
+    try {
+      V1Lease latest = leaseRefer.get();
+      latest.setSpec(getLeaseFromRecord(record));
+      V1Lease updatedLease =
+          coordinationV1Api.replaceNamespacedLease(name, namespace, latest, null, null, null);
+      leaseRefer.set(updatedLease);
+      return true;
+    } catch (ApiException e) {
+      if (e.getCode() == HttpURLConnection.HTTP_CONFLICT) {
+        log.debug("received {} when creating configmap lock", e.getCode(), e);
+      } else {
+        log.error("received {} when creating configmap lock", e.getCode(), e);
+      }
+      return false;
+    }
+  }
+
+  @Override
+  public String identity() {
+    return identity;
+  }
+
+  @Override
+  public String describe() {
+    return namespace + "/" + name;
+  }
+
+  private LeaderElectionRecord getRecordFromLease(V1LeaseSpec lease) {
+    LeaderElectionRecord record = new LeaderElectionRecord();
+    if (lease.getAcquireTime() != null) {
+      record.setAcquireTime(lease.getAcquireTime().toDate());
+    }
+    if (lease.getRenewTime() != null) {
+      record.setRenewTime(lease.getRenewTime().toDate());
+    }
+    record.setHolderIdentity(lease.getHolderIdentity());
+    record.setLeaderTransitions(lease.getLeaseTransitions());
+    record.setLeaseDurationSeconds(lease.getLeaseDurationSeconds());
+    return record;
+  }
+
+  private V1LeaseSpec getLeaseFromRecord(LeaderElectionRecord record) {
+    return new V1LeaseSpec()
+        .acquireTime(new DateTime(record.getAcquireTime()))
+        .renewTime(new DateTime(record.getRenewTime()))
+        .holderIdentity(record.getHolderIdentity())
+        .leaseDurationSeconds(record.getLeaseDurationSeconds())
+        .leaseTransitions(record.getLeaderTransitions());
+  }
+}