NIFI-4839 - Updating README and cleaning up descriptions and comments

- Making registryClientId optional and auto selecting when only one is available
- Added delete-bucket command
- Added delete-flow command for registry

nifi-toolkit/nifi-toolkit-cli/README.md

@@ -123,3 +123,32 @@ Example of json output for list-buckets:
         "href" : "buckets/3c7b7467-0012-4d8f-a918-6aa42b6b9d39"
       }
     } ]
+    
+## Adding Commands
+
+To add a NiFi command, create a new class that extends AbstractNiFiCommand:
+
+    public class MyCommand extends AbstractNiFiCommand {
+    
+      public MyCommand() {
+          super("my-command");
+      }
+      
+      @Override
+      protected void doExecute(NiFiClient client, Properties properties) 
+              throws NiFiClientException, IOException, MissingOptionException, CommandException {
+          // TODO implement        
+      }
+  
+      @Override
+      public String getDescription() {
+          return "This is my new command";
+      }
+    }
+    
+Add the new command to NiFiCommandGroup:
+
+    commands.add(new MyCommand());
+
+To add a NiFi Registry command, perform the same steps, but extend from 
+AbstractNiFiRegistryCommand, and add the command to NiFiRegistryCommandGroup.

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/api/Command.java

@@ -20,7 +20,7 @@ import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.Options;
 
 /**
- * Represents a command to execute against NiFi registry.
+ * Represents a command to execute.
  */
 public interface Command {
 
@@ -32,7 +32,7 @@ public interface Command {
     void initialize(Context context);
 
     /**
-     * @return the name of the command that will be specified as the first argument to the tool
+     * @return the name of the command
      */
     String getName();
 

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/CommandOption.java

@@ -65,6 +65,7 @@ public enum CommandOption {
     PROTOCOL("pro", "protocol", "The security protocol to use, such as TLSv.1.2", true),
 
     // Miscellaneous
+    FORCE("force", "force", "Indicates to force a delete operation", false),
     OUTPUT_TYPE("ot", "outputType", "The type of output to produce (json or simple)", true),
     VERBOSE("verbose", "verbose", "Indicates that verbose output should be provided", false),
     HELP("h", "help", "Help", false)

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/nifi/pg/PGImport.java

@@ -30,9 +30,12 @@ import org.apache.nifi.web.api.dto.PositionDTO;
 import org.apache.nifi.web.api.dto.ProcessGroupDTO;
 import org.apache.nifi.web.api.dto.VersionControlInformationDTO;
 import org.apache.nifi.web.api.entity.ProcessGroupEntity;
+import org.apache.nifi.web.api.entity.RegistryClientEntity;
+import org.apache.nifi.web.api.entity.RegistryClientsEntity;
 
 import java.io.IOException;
 import java.util.Properties;
+import java.util.Set;
 
 /**
  * Command for importing a flow to NiFi from NiFi Registry.
@@ -46,7 +49,8 @@ public class PGImport extends AbstractNiFiCommand {
     @Override
     public String getDescription() {
         return "Creates a new process group by importing a versioned flow from a registry. If no process group id is " +
-                "specified, then the created process group will be placed in the root group.";
+                "specified, then the created process group will be placed in the root group. If only one registry client " +
+                "exists in NiFi, then it does not need to be specified and will be automatically selected.";
     }
 
     @Override
@@ -62,11 +66,29 @@ public class PGImport extends AbstractNiFiCommand {
     protected void doExecute(final NiFiClient client, final Properties properties)
             throws NiFiClientException, IOException, MissingOptionException {
 
-        final String registryId = getRequiredArg(properties, CommandOption.REGISTRY_CLIENT_ID);
         final String bucketId = getRequiredArg(properties, CommandOption.BUCKET_ID);
         final String flowId = getRequiredArg(properties, CommandOption.FLOW_ID);
         final Integer flowVersion = getRequiredIntArg(properties, CommandOption.FLOW_VERSION);
 
+        // if a registry client is specified use it, otherwise see if there is only one available and use that,
+        // if more than one is available then throw an exception because we don't know which one to use
+        String registryId = getArg(properties, CommandOption.REGISTRY_CLIENT_ID);
+        if (StringUtils.isBlank(registryId)) {
+            final RegistryClientsEntity registries = client.getControllerClient().getRegistryClients();
+
+            final Set<RegistryClientEntity> entities = registries.getRegistries();
+            if (entities == null || entities.isEmpty()) {
+                throw new NiFiClientException("No registry clients available");
+            }
+
+            if (entities.size() == 1) {
+                registryId = entities.stream().findFirst().get().getId();
+            } else {
+                throw new MissingOptionException(CommandOption.REGISTRY_CLIENT_ID.getLongName()
+                        + " must be provided when there is more than one available");
+            }
+        }
+
         // get the optional id of the parent PG, otherwise fallback to the root group
         String parentPgId = getArg(properties, CommandOption.PG_ID);
         if (StringUtils.isBlank(parentPgId)) {

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/registry/NiFiRegistryCommandGroup.java

@@ -19,8 +19,10 @@ package org.apache.nifi.toolkit.cli.impl.command.registry;
 import org.apache.nifi.toolkit.cli.api.Command;
 import org.apache.nifi.toolkit.cli.impl.command.AbstractCommandGroup;
 import org.apache.nifi.toolkit.cli.impl.command.registry.bucket.CreateBucket;
+import org.apache.nifi.toolkit.cli.impl.command.registry.bucket.DeleteBucket;
 import org.apache.nifi.toolkit.cli.impl.command.registry.bucket.ListBuckets;
 import org.apache.nifi.toolkit.cli.impl.command.registry.flow.CreateFlow;
+import org.apache.nifi.toolkit.cli.impl.command.registry.flow.DeleteFlow;
 import org.apache.nifi.toolkit.cli.impl.command.registry.flow.ExportFlowVersion;
 import org.apache.nifi.toolkit.cli.impl.command.registry.flow.ImportFlowVersion;
 import org.apache.nifi.toolkit.cli.impl.command.registry.flow.ListFlowVersions;
@@ -47,8 +49,10 @@ public class NiFiRegistryCommandGroup extends AbstractCommandGroup {
         commandList.add(new CurrentUser());
         commandList.add(new ListBuckets());
         commandList.add(new CreateBucket());
+        commandList.add(new DeleteBucket());
         commandList.add(new ListFlows());
         commandList.add(new CreateFlow());
+        commandList.add(new DeleteFlow());
         commandList.add(new ListFlowVersions());
         commandList.add(new ExportFlowVersion());
         commandList.add(new ImportFlowVersion());

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/registry/bucket/DeleteBucket.java

@@ -0,0 +1,70 @@
+/*
+ * 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.
+ */
+package org.apache.nifi.toolkit.cli.impl.command.registry.bucket;
+
+import org.apache.commons.cli.ParseException;
+import org.apache.nifi.registry.client.BucketClient;
+import org.apache.nifi.registry.client.FlowClient;
+import org.apache.nifi.registry.client.NiFiRegistryClient;
+import org.apache.nifi.registry.client.NiFiRegistryException;
+import org.apache.nifi.registry.flow.VersionedFlow;
+import org.apache.nifi.toolkit.cli.api.Context;
+import org.apache.nifi.toolkit.cli.impl.command.CommandOption;
+import org.apache.nifi.toolkit.cli.impl.command.registry.AbstractNiFiRegistryCommand;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Properties;
+
+/**
+ * Deletes a bucket from the given registry.
+ */
+public class DeleteBucket extends AbstractNiFiRegistryCommand {
+
+    public DeleteBucket() {
+        super("delete-bucket");
+    }
+
+    @Override
+    public String getDescription() {
+        return "Deletes the bucket with the given id. If the bucket contains any items then the force option must be used.";
+    }
+
+    @Override
+    protected void doInitialize(Context context) {
+        addOption(CommandOption.BUCKET_ID.createOption());
+        addOption(CommandOption.FORCE.createOption());
+    }
+
+    @Override
+    protected void doExecute(final NiFiRegistryClient client, final Properties properties)
+            throws IOException, NiFiRegistryException, ParseException {
+
+        final String bucketId = getRequiredArg(properties, CommandOption.BUCKET_ID);
+        final boolean forceDelete = properties.containsKey(CommandOption.FORCE.getLongName());
+
+        final FlowClient flowClient = client.getFlowClient();
+        final List<VersionedFlow> flowsInBucket = flowClient.getByBucket(bucketId);
+
+        if (flowsInBucket != null && flowsInBucket.size() > 0 && !forceDelete) {
+            throw new NiFiRegistryException("Bucket is not empty, use --" + CommandOption.FORCE.getLongName() + " to delete");
+        } else {
+            final BucketClient bucketClient = client.getBucketClient();
+            bucketClient.delete(bucketId);
+        }
+    }
+}

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/registry/flow/DeleteFlow.java

@@ -0,0 +1,72 @@
+/*
+ * 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.
+ */
+package org.apache.nifi.toolkit.cli.impl.command.registry.flow;
+
+import org.apache.commons.cli.ParseException;
+import org.apache.nifi.registry.client.FlowClient;
+import org.apache.nifi.registry.client.FlowSnapshotClient;
+import org.apache.nifi.registry.client.NiFiRegistryClient;
+import org.apache.nifi.registry.client.NiFiRegistryException;
+import org.apache.nifi.registry.flow.VersionedFlowSnapshotMetadata;
+import org.apache.nifi.toolkit.cli.api.Context;
+import org.apache.nifi.toolkit.cli.impl.command.CommandOption;
+import org.apache.nifi.toolkit.cli.impl.command.registry.AbstractNiFiRegistryCommand;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Properties;
+
+/**
+ * Deletes a flow from the given registry.
+ */
+public class DeleteFlow extends AbstractNiFiRegistryCommand {
+
+    public DeleteFlow() {
+        super("delete-flow");
+    }
+
+    @Override
+    public String getDescription() {
+        return "Deletes a flow from the registry. If the flow has one or more versions then the force option must be used.";
+    }
+
+    @Override
+    protected void doInitialize(Context context) {
+        addOption(CommandOption.FLOW_ID.createOption());
+        addOption(CommandOption.FORCE.createOption());
+    }
+
+    @Override
+    protected void doExecute(final NiFiRegistryClient client, final Properties properties)
+            throws IOException, NiFiRegistryException, ParseException {
+
+        final String flowId = getRequiredArg(properties, CommandOption.FLOW_ID);
+        final boolean forceDelete = properties.containsKey(CommandOption.FORCE.getLongName());
+
+        final String bucketId = getBucketId(client, flowId);
+
+        final FlowSnapshotClient flowSnapshotClient = client.getFlowSnapshotClient();
+        final List<VersionedFlowSnapshotMetadata> snapshotMetadata = flowSnapshotClient.getSnapshotMetadata(bucketId, flowId);
+
+        if (snapshotMetadata != null && snapshotMetadata.size() > 0 && !forceDelete) {
+            throw new NiFiRegistryException("Flow has versions, use --" + CommandOption.FORCE.getLongName() + " to delete");
+        } else {
+            final FlowClient flowClient = client.getFlowClient();
+            flowClient.delete(bucketId, flowId);
+        }
+    }
+}

nifi-toolkit/nifi-toolkit-cli/src/main/java/org/apache/nifi/toolkit/cli/impl/command/registry/flow/ImportFlowVersion.java

@@ -48,7 +48,7 @@ public class ImportFlowVersion extends AbstractNiFiRegistryCommand {
 
     @Override
     public String getDescription() {
-        return "Imports a version of a flow that was previously exported. The imported version automatically becomes " +
+        return "Imports a version of a flow from a local file, or a URL. The imported version automatically becomes " +
                 "the next version of the given flow.";
     }