/**
* 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.
*/
package com.seyren.core.service.notification;
import com.seyren.core.domain.Alert;
import com.seyren.core.domain.Check;
import com.seyren.core.domain.Subscription;
import com.seyren.core.domain.SubscriptionType;
import com.seyren.core.exception.NotificationFailedException;
import com.seyren.core.util.config.SeyrenConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.smi.*;
import org.snmp4j.transport.DefaultUdpTransportMapping;
import javax.inject.Inject;
import javax.inject.Named;
import java.io.IOException;
import java.util.List;
@Named
public class SnmpTrapNotificationService implements NotificationService {
private static final Logger LOGGER = LoggerFactory.getLogger(SnmpTrapNotificationService.class);
private final SeyrenConfig seyrenConfig;
@Inject
public SnmpTrapNotificationService(SeyrenConfig seyrenConfig) {
this.seyrenConfig = seyrenConfig;
}
@Override
public void sendNotification(Check check, Subscription subscription, List<Alert> alerts) throws NotificationFailedException {
LOGGER.info("Seyren notification '{}' changed state to '{}' @ '{}' with {} alert(s)",
check.getName(),
check.getState().name(),
url(check),
alerts.size());
// Create the SNMP instance
Snmp snmp = createSnmpConnection();
// Specify receiver
Address targetaddress = new UdpAddress(seyrenConfig.getSnmpHost() + "/" + seyrenConfig.getSnmpPort());
CommunityTarget target = new CommunityTarget();
target.setCommunity(octetString(seyrenConfig.getSnmpCommunity()));
target.setVersion(SnmpConstants.version2c);
target.setAddress(targetaddress);
for (Alert alert : alerts) {
// Create PDU
PDU trap = new PDU();
trap.setType(PDU.TRAP);
OID oid = new OID(seyrenConfig.getSnmpOID());
trap.add(new VariableBinding(SnmpConstants.snmpTrapOID, oid));
trap.add(new VariableBinding(SnmpConstants.sysUpTime, new TimeTicks(5000)));
trap.add(variableBinding(SnmpConstants.sysDescr, "Seyren Alert"));
//Add Payload
trap.add(variableBinding(oid, check.getName()));
trap.add(variableBinding(oid, alert.getTarget()));
trap.add(variableBinding(oid, check.getState().name()));
trap.add(variableBinding(oid, alert.getValue().toString()));
trap.add(variableBinding(oid, check.getWarn().toString()));
trap.add(variableBinding(oid, check.getError().toString()));
// Send
sendAlert(check, snmp, target, trap);
}
// Cleanup
closeSnmpConnection(snmp);
}
@Override
public boolean canHandle(SubscriptionType subscriptionType) {
return subscriptionType == SubscriptionType.SNMP;
}
private void closeSnmpConnection(Snmp snmp) {
try {
snmp.close();
} catch (IOException e) {
LOGGER.warn("Closing SNMP instance failed.", e);
}
}
private void sendAlert(Check check, Snmp snmp, CommunityTarget target, PDU trap) {
try {
if (snmp != null) {
snmp.send(trap, target, null, null);
} else {
LOGGER.info("Seyren notification failed for {} because the Snmp instance was null", check.getName());
}
} catch (IOException e) {
throw new NotificationFailedException("Sending notification via SNMP trap failed.", e);
}
}
private Snmp createSnmpConnection() {
try {
return new Snmp(new DefaultUdpTransportMapping());
} catch (IOException e) {
throw new NotificationFailedException("Sending notification via SNMP trap failed.", e);
}
}
private VariableBinding variableBinding(OID oid, String value) {
return new VariableBinding(oid, octetString(value));
}
private OctetString octetString(String value) {
return new OctetString(value);
}
private String url(Check check) {
return String.format("%s/#/checks/%s", seyrenConfig.getBaseUrl(), check.getName());
}
}