/*-
* ========================LICENSE_START=================================
* O-RAN-SC
* %%
* Copyright (C) 2020 Nordix Foundation
* %%
* 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.
* ========================LICENSE_END===================================
*/
package org.oransc.policyagent.clients;
import org.oransc.policyagent.clients.A1Client.A1ProtocolType;
import org.oransc.policyagent.configuration.ApplicationConfig;
import org.oransc.policyagent.configuration.ControllerConfig;
import org.oransc.policyagent.exceptions.ServiceException;
import org.oransc.policyagent.repository.Ric;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import reactor.core.publisher.Mono;
/**
* Factory for A1 clients that supports four different protocol versions of the
* A1 api.
*/
public class A1ClientFactory {
private static final Logger logger = LoggerFactory.getLogger(A1ClientFactory.class);
private final ApplicationConfig appConfig;
@Autowired
public A1ClientFactory(ApplicationConfig appConfig) {
this.appConfig = appConfig;
}
/**
* Creates an A1 client with the correct A1 protocol for the provided Ric.
*
*
* It detects the protocol version by trial and error, since there is no
* getVersion method specified in the A1 api yet.
*
*
* As a side effect it also sets the protocol version in the provided Ric. This
* means that after the first successful creation it won't have to try which
* protocol to use, but can create the client directly.
*
* @param ric The RIC to get a client for.
* @return a client with the correct protocol, or a ServiceException if none of
* the protocols are supported by the Ric.
*/
public Mono createA1Client(Ric ric) {
return getProtocolVersion(ric) //
.flatMap(version -> createA1ClientMono(ric, version));
}
A1Client createClient(Ric ric, A1ProtocolType version) throws ServiceException {
if (version == A1ProtocolType.STD_V1_1) {
assertNoControllerConfig(ric, version);
return new StdA1ClientVersion1(ric.getConfig());
} else if (version == A1ProtocolType.OSC_V1) {
assertNoControllerConfig(ric, version);
return new OscA1Client(ric.getConfig());
} else if (version == A1ProtocolType.SDNC_OSC_STD_V1_1 || version == A1ProtocolType.SDNC_OSC_OSC_V1) {
return new SdncOscA1Client(version, ric.getConfig(), getControllerConfig(ric));
} else if (version == A1ProtocolType.SDNC_ONAP) {
return new SdncOnapA1Client(ric.getConfig(), getControllerConfig(ric));
} else {
logger.error("Unhandled protocol: {}", version);
throw new ServiceException("Unhandled protocol");
}
}
private ControllerConfig getControllerConfig(Ric ric) throws ServiceException {
String controllerName = ric.getConfig().controllerName();
if (controllerName.isEmpty()) {
throw new ServiceException("No controller configured for RIC: " + ric.name());
}
return this.appConfig.getControllerConfig(controllerName);
}
private void assertNoControllerConfig(Ric ric, A1ProtocolType version) throws ServiceException {
if (!ric.getConfig().controllerName().isEmpty()) {
throw new ServiceException(
"Controller config should be empty, ric: " + ric.name() + " when using protocol version: " + version);
}
}
private Mono createA1ClientMono(Ric ric, A1ProtocolType version) {
try {
return Mono.just(createClient(ric, version));
} catch (ServiceException e) {
return Mono.error(e);
}
}
private Mono getProtocolVersion(Ric ric) {
if (ric.getProtocolVersion() == A1ProtocolType.UNKNOWN) {
return fetchVersion(ric, A1ProtocolType.STD_V1_1) //
.onErrorResume(notUsed -> fetchVersion(ric, A1ProtocolType.OSC_V1)) //
.onErrorResume(notUsed -> fetchVersion(ric, A1ProtocolType.SDNC_OSC_STD_V1_1)) //
.onErrorResume(notUsed -> fetchVersion(ric, A1ProtocolType.SDNC_ONAP)) //
.doOnNext(ric::setProtocolVersion)
.doOnNext(version -> logger.debug("Established protocol version:{} for Ric: {}", version, ric.name())) //
.doOnError(notUsed -> logger.warn("Could not get protocol version from RIC: {}", ric.name())) //
.onErrorResume(
notUsed -> Mono.error(new ServiceException("Protocol negotiation failed for " + ric.name())));
} else {
return Mono.just(ric.getProtocolVersion());
}
}
private Mono fetchVersion(Ric ric, A1ProtocolType protocolType) {
return createA1ClientMono(ric, protocolType) //
.flatMap(A1Client::getProtocolVersion);
}
}