AbstractGCSProcessor.java

/*
 * 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.processors.gcp.storage;

import com.google.auth.oauth2.GoogleCredentials;
import com.google.cloud.RetryParams;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import com.google.cloud.storage.spi.StorageRpc;
import com.google.common.collect.ImmutableList;
import org.apache.nifi.components.PropertyDescriptor;
import org.apache.nifi.processor.ProcessContext;
import org.apache.nifi.processor.Relationship;
import org.apache.nifi.processors.gcp.AbstractGCPProcessor;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Base class for creating processors which connect to Google Cloud Storage.
 *
 * Every GCS processor operation requires a bucket, whether it's reading or writing from said bucket.
 */
public abstract class AbstractGCSProcessor extends AbstractGCPProcessor<Storage, StorageRpc, StorageOptions> {
    public static final Relationship REL_SUCCESS =
            new Relationship.Builder().name("success")
                    .description("FlowFiles are routed to this relationship after a successful Google Cloud Storage operation.")
                    .build();
    public static final Relationship REL_FAILURE =
            new Relationship.Builder().name("failure")
                    .description("FlowFiles are routed to this relationship if the Google Cloud Storage operation fails.")
                    .build();

    public static final Set<Relationship> relationships = Collections.unmodifiableSet(
            new HashSet<>(Arrays.asList(REL_SUCCESS, REL_FAILURE)));

    @Override
    public Set<Relationship> getRelationships() {
        return relationships;
    }

    @Override
    public List<PropertyDescriptor> getSupportedPropertyDescriptors() {
        return ImmutableList.<PropertyDescriptor>builder()
                .addAll(super.getSupportedPropertyDescriptors())
                .build();
    }

    @Override
    protected StorageOptions getServiceOptions(ProcessContext context, GoogleCredentials credentials) {
        final String projectId = context.getProperty(PROJECT_ID).getValue();
        final Integer retryCount = Integer.valueOf(context.getProperty(RETRY_COUNT).getValue());

        return StorageOptions.newBuilder()
                .setCredentials(credentials)
                .setProjectId(projectId)
                .setRetryParams(RetryParams.newBuilder()
                        .setRetryMaxAttempts(retryCount)
                        .setRetryMinAttempts(retryCount)
                        .build())
                .build();
    }
}