package com.thinkbiganalytics.nifi.rest.client;
/*-
* #%L
* kylo-nifi-rest-client-api
* %%
* Copyright (C) 2017 ThinkBig Analytics
* %%
* 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.
* #L%
*/
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import com.google.common.util.concurrent.Uninterruptibles;
import com.thinkbiganalytics.nifi.rest.support.NifiConstants;
import org.apache.nifi.web.api.dto.BulletinDTO;
import org.apache.nifi.web.api.dto.ControllerServiceDTO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import javax.annotation.Nonnull;
import javax.ws.rs.ClientErrorException;
/**
* Provides a standard implementation of {@link NiFiControllerServicesRestClient} that can be extended for different NiFi versions.
*/
public abstract class AbstractNiFiControllerServicesRestClient implements NiFiControllerServicesRestClient {
private static final Logger log = LoggerFactory.getLogger(AbstractNiFiControllerServicesRestClient.class);
/**
* Asynchronous executor
*/
@Nonnull
protected final ExecutorService executor = Executors.newSingleThreadExecutor(
new ThreadFactoryBuilder()
.setThreadFactory(Executors.defaultThreadFactory())
.setDaemon(true)
.setNameFormat("nifi-controller-services-client-pool-%d")
.build()
);
@Nonnull
@Override
public Future<Optional<ControllerServiceDTO>> disableAndDeleteAsync(@Nonnull final String id) {
return executor.submit(() -> {
try {
updateStateById(id, State.DISABLED);
} catch (final Exception e) {
log.error("Failed to disable controller service: {}", id, e);
}
return delete(id);
});
}
@Override
public ControllerServiceDTO updateStateById(@Nonnull final String id, @Nonnull final State state) {
if (state == State.DISABLED) {
return updateStateByIdWithRetries(id, state.name(), 60, 1, TimeUnit.SECONDS);
} else {
return updateStateByIdWithRetries(id, state.name(), 3, 300, TimeUnit.MILLISECONDS);
}
}
/**
* Sends a request to update the state of the specified controller service and waits for it to finish updating.
*
* @param id the controller service id
* @param state the new state
* @param retries number of retries, at least 0; will try {@code retries} + 1 times
* @param timeout duration to wait between retries
* @param timeUnit unit of time for {@code timeout}
* @return the controller service, if updated
* @throws NifiClientRuntimeException if the state cannot be changed
* @throws NifiComponentNotFoundException if the controller service does not exist
*/
protected ControllerServiceDTO updateStateByIdWithRetries(@Nonnull final String id, @Nonnull final String state, final int retries, final int timeout, @Nonnull final TimeUnit timeUnit) {
// Update controller service
ControllerServiceDTO controllerService = new ControllerServiceDTO();
controllerService.setId(id);
controllerService.setState(state);
controllerService = update(controllerService);
// Wait for finished
for (int count = 0; isPendingState(controllerService.getState(), state) && count < retries; ++count) {
Uninterruptibles.sleepUninterruptibly(timeout, timeUnit);
controllerService = findById(id).orElseThrow(() -> new NifiComponentNotFoundException(id, NifiConstants.NIFI_COMPONENT_TYPE.CONTROLLER_SERVICE, null));
}
// Verify state change or throw bulletin message
if (state.equals(controllerService.getState())) {
return controllerService;
} else {
String msg = id;
try {
final List<BulletinDTO> bulletins = getClient().getBulletins(id);
if (!bulletins.isEmpty()) {
msg = bulletins.get(0).getMessage();
}
} catch (final ClientErrorException e) {
// ignored
}
throw new NifiClientRuntimeException("Timeout waiting for controller service to be " + state + ": " + msg);
}
}
/**
* Indicates if a controller service is pending a change to the specified state.
*
* @param currentState the current state of the controller service
* @param finalState the expected state of the controller service
* @return {@code true} if the controller service is still transitioning to the final state, or {@code false} otherwise
*/
private boolean isPendingState(@Nonnull final String currentState, @Nonnull final String finalState) {
return ("ENABLING".equals(currentState) && "ENABLED".equals(finalState)) || ("DISABLING".equals(currentState) && "DISABLED".equals(finalState));
}
}