nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-components/src/main/java/org/apache/nifi/registry/flow/StandardFlowRegistryClient.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.registry.flow;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.net.ssl.SSLContext;
import org.apache.http.client.utils.URIBuilder;
import org.apache.nifi.security.util.SslContextFactory;
import org.apache.nifi.security.util.StandardTlsConfiguration;
import org.apache.nifi.security.util.TlsException;
import org.apache.nifi.util.NiFiProperties;

public class StandardFlowRegistryClient implements FlowRegistryClient {
    private NiFiProperties nifiProperties;
    private final ConcurrentMap<String, FlowRegistry> registryById = new ConcurrentHashMap<>();

    @Override
    public FlowRegistry getFlowRegistry(String registryId) {
        return registryById.get(registryId);
    }

    @Override
    public Set<String> getRegistryIdentifiers() {
        return registryById.keySet();
    }

    @Override
    public void addFlowRegistry(final FlowRegistry registry) {
        final boolean duplicateName = registryById.values().stream()
            .anyMatch(reg -> reg.getName().equals(registry.getName()));

        if (duplicateName) {
            throw new IllegalStateException("Cannot add Flow Registry because a Flow Registry already exists with the name " + registry.getName());
        }

        final FlowRegistry existing = registryById.putIfAbsent(registry.getIdentifier(), registry);
        if (existing != null) {
            throw new IllegalStateException("Cannot add Flow Registry " + registry + " because a Flow Registry already exists with the ID " + registry.getIdentifier());
        }
    }

    @Override
    public FlowRegistry addFlowRegistry(final String registryId, final String registryName, final String registryUrl, final String description) {
        final URI uri;
        try {
            // Handles case where the URI entered has a trailing slash, or includes the trailing /nifi-registry-api
            uri = new URIBuilder(registryUrl).setPath("").removeQuery().build();
        } catch (URISyntaxException e) {
            throw new IllegalArgumentException("The given Registry URL is not valid: " + registryUrl);
        }

        final String uriScheme = uri.getScheme();
        if (uriScheme == null) {
            throw new IllegalArgumentException("The given Registry URL is not valid: " + registryUrl);
        }

        final String registryBaseUrl = uri.toString();

        final FlowRegistry registry;
        if (uriScheme.equalsIgnoreCase("http") || uriScheme.equalsIgnoreCase("https")) {
            try {
                final SSLContext sslContext = SslContextFactory.createSslContext(StandardTlsConfiguration.fromNiFiProperties(nifiProperties));

                if (sslContext == null && uriScheme.equalsIgnoreCase("https")) {
                    throw new IllegalStateException("Failed to create Flow Registry for URI " + registryUrl
                            + " because this NiFi is not configured with a Keystore/Truststore, so it is not capable of communicating with a secure Registry. "
                            + "Please populate NiFi's Keystore/Truststore properties or connect to a NiFi Registry over http instead of https.");
                }

                registry = new RestBasedFlowRegistry(this, registryId, registryBaseUrl, sslContext, registryName);
                registry.setDescription(description);
            } catch (TlsException e) {
                throw new IllegalStateException("Failed to create Flow Registry for URI " + registryUrl
                        + " because this NiFi instance has an invalid TLS configuration", e);
            }
        } else {
            throw new IllegalArgumentException("Cannot create Flow Registry with URI of " + registryUrl
                + " because there are no known implementations of Flow Registries that can handle URIs of scheme " + uriScheme);
        }

        addFlowRegistry(registry);
        return registry;
    }

    @Override
    public FlowRegistry removeFlowRegistry(final String registryId) {
        return registryById.remove(registryId);
    }

    public void setProperties(final NiFiProperties nifiProperties) {
        this.nifiProperties = nifiProperties;
    }
}