Add CloudConfig operations

helix-core/src/main/java/org/apache/helix/ConfigAccessor.java

@@ -30,6 +30,7 @@
 import org.apache.helix.manager.zk.ZKUtil;
 import org.apache.helix.manager.zk.client.HelixZkClient;
 import org.apache.helix.model.ClusterConfig;
+import org.apache.helix.model.CloudConfig;
 import org.apache.helix.model.ConfigScope;
 import org.apache.helix.model.HelixConfigScope;
 import org.apache.helix.model.HelixConfigScope.ConfigScopeProperty;
@@ -562,6 +563,28 @@ public ClusterConfig getClusterConfig(String clusterName) {
     return new ClusterConfig(record);
   }
 
+  /**
+   * Get CloudConfig of the given cluster.
+   * @param clusterName
+   * @return The instance of {@link CloudConfig}
+   */
+  public CloudConfig getCloudConfig(String clusterName) {
+    if (!ZKUtil.isClusterSetup(clusterName, zkClient)) {
+      throw new HelixException(
+          String.format("Failed to get config. cluster: %s is not setup.", clusterName));
+    }
+    HelixConfigScope scope =
+        new HelixConfigScopeBuilder(ConfigScopeProperty.CLOUD).forCluster(clusterName).build();
+    ZNRecord record = getConfigZnRecord(scope);
+
+    if (record == null) {
+      LOG.warn("No cloud config found at {}.", scope.getZkPath());
+      return null;
+    }
+
+    return new CloudConfig(record);
+  }
+
   /**
    * Get RestConfig of the given cluster.
    *

helix-core/src/main/java/org/apache/helix/PropertyKey.java

@@ -24,6 +24,7 @@
 import java.util.Arrays;
 import java.util.Objects;
 
+import org.apache.helix.model.CloudConfig;
 import org.apache.helix.model.ClusterConfig;
 import org.apache.helix.model.ClusterConstraints;
 import org.apache.helix.model.ControllerHistory;
@@ -214,6 +215,16 @@ public PropertyKey clusterConfig() {
           _clusterName, ConfigScopeProperty.CLUSTER.toString(), _clusterName);
     }
 
+
+    /**
+     * Get a property key associated with this Cloud configuration
+     * @return {@link PropertyKey}
+     */
+    public PropertyKey cloudConfig() {
+      return new PropertyKey(CONFIGS, ConfigScopeProperty.CLOUD, CloudConfig.class,
+          _clusterName, ConfigScopeProperty.CLOUD.name(), _clusterName);
+    }
+
     /**
      * Get a property key associated with {@link InstanceConfig}
      * @return {@link PropertyKey}

helix-core/src/main/java/org/apache/helix/cloud/constants/CloudProvider.java

@@ -0,0 +1,25 @@
+package org.apache.helix.cloud.constants;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+public enum CloudProvider {
+  AZURE,
+  CUSTOMIZED
+}

helix-core/src/main/java/org/apache/helix/model/CloudConfig.java

@@ -0,0 +1,290 @@
+package org.apache.helix.model;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+import org.apache.helix.HelixException;
+import org.apache.helix.HelixProperty;
+import org.apache.helix.ZNRecord;
+import org.apache.helix.cloud.constants.CloudProvider;
+
+/**
+ * Cloud configurations
+ */
+public class CloudConfig extends HelixProperty {
+  /**
+   * Configurable characteristics of a cloud.
+   * NOTE: Do NOT use this field name directly, use its corresponding getter/setter in the
+   * CloudConfig.
+   */
+  public enum CloudConfigProperty {
+    CLOUD_ENABLED, // determine whether the cluster is inside cloud environment.
+    CLOUD_PROVIDER, // the environment the cluster is in, e.g. Azure, AWS, or Customized
+    CLOUD_ID, // the cloud Id that belongs to this cluster.
+
+    // If user uses Helix supported default provider, the below entries will not be shown in
+    // CloudConfig.
+    CLOUD_INFO_SOURCE, // the source for retrieving the cloud information.
+    CLOUD_INFO_PROCESSOR_NAME // the name of the function that processes the fetching and parsing of
+                              // cloud information.
+  }
+
+  /* Default values */
+  private static final boolean DEFAULT_CLOUD_ENABLED = false;
+
+  /**
+   * Instantiate the CloudConfig for the cloud
+   * @param cluster
+   */
+  public CloudConfig(String cluster) {
+    super(cluster);
+  }
+
+  /**
+   * Instantiate with a pre-populated record
+   * @param record a ZNRecord corresponding to a cloud configuration
+   */
+  public CloudConfig(ZNRecord record) {
+    super(record);
+  }
+
+  /**
+   * Instantiate the config using each field individually.
+   * Users should use CloudConfig.Builder to create CloudConfig.
+   * @param cluster
+   * @param enabled
+   * @param cloudID
+   */
+  public CloudConfig(String cluster, boolean enabled, CloudProvider cloudProvider, String cloudID,
+      List<String> cloudInfoSource, String cloudProcessorName) {
+    super(cluster);
+    _record.setBooleanField(CloudConfigProperty.CLOUD_ENABLED.name(), enabled);
+    _record.setSimpleField(CloudConfigProperty.CLOUD_PROVIDER.name(), cloudProvider.name());
+    _record.setSimpleField(CloudConfigProperty.CLOUD_ID.name(), cloudID);
+    if (cloudProvider.equals(CloudProvider.CUSTOMIZED)) {
+      _record
+          .setSimpleField(CloudConfigProperty.CLOUD_INFO_PROCESSOR_NAME.name(), cloudProcessorName);
+      _record.setListField(CloudConfigProperty.CLOUD_INFO_SOURCE.name(), cloudInfoSource);
+    }
+  }
+
+  /**
+   * Enable/Disable the CLOUD_ENABLED field.
+   * @param enabled
+   */
+  public void setCloudEnabled(boolean enabled) {
+    _record.setBooleanField(CloudConfigProperty.CLOUD_ENABLED.name(), enabled);
+  }
+
+  /**
+   * Whether CLOUD_ENABLED field is enabled or not.
+   * @return
+   */
+  public boolean isCloudEnabled() {
+    return _record.getBooleanField(CloudConfigProperty.CLOUD_ENABLED.name(), false);
+  }
+
+  /**
+   * Set the cloudID field.
+   * @param cloudID
+   */
+  public void setCloudID(String cloudID) {
+    _record.setSimpleField(CloudConfigProperty.CLOUD_ID.name(), cloudID);
+  }
+
+  /**
+   * Get the CloudID field.
+   * @return CloudID
+   */
+  public String getCloudID() {
+    return _record.getSimpleField(CloudConfigProperty.CLOUD_ID.name());
+  }
+
+  /**
+   * Set the CLOUD_INFO_SOURCE field.
+   * @param cloudInfoSources
+   */
+  public void setCloudInfoSource(List<String> cloudInfoSources) {
+    _record.setListField(CloudConfigProperty.CLOUD_INFO_SOURCE.name(), cloudInfoSources);
+  }
+
+  /**
+   * Get the CLOUD_INFO_SOURCE field.
+   * @return CLOUD_INFO_SOURCE field.
+   */
+  public List<String> getCloudInfoSources() {
+    return _record.getListField(CloudConfigProperty.CLOUD_INFO_SOURCE.name());
+  }
+
+  /**
+   * Set the CLOUD_INFO_PROCESSOR_NAME field.
+   * @param cloudInfoProcessorName
+   */
+  public void setCloudInfoFProcessorName(String cloudInfoProcessorName) {
+    _record.setSimpleField(CloudConfigProperty.CLOUD_INFO_PROCESSOR_NAME.name(),
+        cloudInfoProcessorName);
+  }
+
+  /**
+   * Get the CLOUD_INFO_PROCESSOR_NAME field.
+   * @return CLOUD_INFO_PROCESSOR_NAME field.
+   */
+  public String getCloudInfoProcessorName() {
+    return _record.getSimpleField(CloudConfigProperty.CLOUD_INFO_PROCESSOR_NAME.name());
+  }
+
+  /**
+   * Set the CLOUD_PROVIDER field.
+   * @param cloudProvider
+   */
+  public void setCloudProvider(CloudProvider cloudProvider) {
+    _record.setSimpleField(CloudConfigProperty.CLOUD_PROVIDER.name(), cloudProvider.name());
+  }
+
+  /**
+   * Get the CLOUD_PROVIDER field.
+   * @return CLOUD_PROVIDER field.
+   */
+  public String getCloudProvider() {
+    return _record.getSimpleField(CloudConfigProperty.CLOUD_PROVIDER.name());
+  }
+
+  public static class Builder {
+    private String _clusterName = null;
+    private CloudProvider _cloudProvider;
+    private boolean _cloudEnabled = DEFAULT_CLOUD_ENABLED;
+    private String _cloudID;
+    private List<String> _cloudInfoSources;
+    private String _cloudInfoProcessorName;
+
+    public CloudConfig build() {
+      validate();
+      return new CloudConfig(_clusterName, _cloudEnabled, _cloudProvider, _cloudID,
+          _cloudInfoSources, _cloudInfoProcessorName);
+    }
+
+    /**
+     * Default constructor
+     */
+    public Builder() {
+    }
+
+    /**
+     * Constructor with Cluster Name as input
+     * @param clusterName
+     */
+    public Builder(String clusterName) {
+      _clusterName = clusterName;
+    }
+
+    /**
+     * Constructor with CloudConfig as input
+     * @param cloudConfig
+     */
+    public Builder(CloudConfig cloudConfig) {
+      _cloudEnabled = cloudConfig.isCloudEnabled();
+      _cloudProvider = CloudProvider.valueOf(cloudConfig.getCloudProvider());
+      _cloudID = cloudConfig.getCloudID();
+      _cloudInfoSources = cloudConfig.getCloudInfoSources();
+      _cloudInfoProcessorName = cloudConfig.getCloudInfoProcessorName();
+    }
+
+    public Builder setClusterName(String v) {
+      _clusterName = v;
+      return this;
+    }
+
+    public Builder setCloudEnabled(boolean isEnabled) {
+      _cloudEnabled = isEnabled;
+      return this;
+    }
+
+    public Builder setCloudProvider(CloudProvider cloudProvider) {
+      _cloudProvider = cloudProvider;
+      return this;
+    }
+
+    public Builder setCloudID(String v) {
+      _cloudID = v;
+      return this;
+    }
+
+    public Builder setCloudInfoSources(List<String> v) {
+      _cloudInfoSources = v;
+      return this;
+    }
+
+    public Builder addCloudInfoSource(String v) {
+      if (_cloudInfoSources == null) {
+        _cloudInfoSources = new ArrayList<String>();
+      }
+      _cloudInfoSources.add(v);
+      return this;
+    }
+
+    public Builder setCloudInfoProcessorName(String v) {
+      _cloudInfoProcessorName = v;
+      return this;
+    }
+
+    public String getClusterName() {
+      return _clusterName;
+    }
+
+    public CloudProvider getCloudProvider() {
+      return _cloudProvider;
+    }
+
+    public boolean getCloudEnabled() {
+      return _cloudEnabled;
+    }
+
+    public String getCloudID() {
+      return _cloudID;
+    }
+
+    public List<String> getCloudInfoSources() {
+      return _cloudInfoSources;
+    }
+
+    public String getCloudInfoProcessorName() {
+      return _cloudInfoProcessorName;
+    }
+
+    private void validate() {
+      if (_cloudEnabled) {
+        if (_cloudID == null) {
+          throw new HelixException(
+              "This Cloud Configuration is Invalid. The CloudID is missing from the config.");
+        }
+        if (_cloudProvider == null) {
+          throw new HelixException(
+              "This Cloud Configuration is Invalid. The Cloud Provider is missing from the config.");
+        } else if (_cloudProvider == CloudProvider.CUSTOMIZED) {
+          if (_cloudInfoProcessorName == null || _cloudInfoSources == null || _cloudInfoSources.size() == 0) {
+            throw new HelixException(
+                "This Cloud Configuration is Invalid. CUSTOMIZED provider has been chosen without defining CloudInfoProcessorName or CloudInfoSources");
+          }
+        }
+      }
+    }
+  }
+}