Java tutorial
/** * This file is part of Graylog. * * Graylog is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Graylog is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Graylog. If not, see <http://www.gnu.org/licenses/>. */ package org.graylog2.alerts; import com.floreysoft.jmte.Engine; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Strings; import org.apache.commons.mail.DefaultAuthenticator; import org.apache.commons.mail.Email; import org.apache.commons.mail.EmailConstants; import org.apache.commons.mail.EmailException; import org.apache.commons.mail.SimpleEmail; import org.graylog2.configuration.EmailConfiguration; import org.graylog2.notifications.Notification; import org.graylog2.notifications.NotificationService; import org.graylog2.plugin.Message; import org.graylog2.plugin.Tools; import org.graylog2.plugin.alarms.AlertCondition; import org.graylog2.plugin.alarms.transports.TransportConfigurationException; import org.graylog2.plugin.configuration.Configuration; import org.graylog2.plugin.streams.Stream; import org.graylog2.plugin.system.NodeId; import org.joda.time.DateTime; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.inject.Inject; import java.net.URI; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import static com.google.common.base.MoreObjects.firstNonNull; import static com.google.common.base.Strings.isNullOrEmpty; import static java.util.Objects.requireNonNull; public class FormattedEmailAlertSender implements AlertSender { private static final Logger LOG = LoggerFactory.getLogger(FormattedEmailAlertSender.class); public static final String bodyTemplate = "##########\n" + "Alert Description: ${check_result.resultDescription}\n" + "Date: ${check_result.triggeredAt}\n" + "Stream ID: ${stream.id}\n" + "Stream title: ${stream.title}\n" + "Stream description: ${stream.description}\n" + "Alert Condition Title: ${alertCondition.title}\n" + "${if stream_url}Stream URL: ${stream_url}${end}\n" + "\n" + "Triggered condition: ${check_result.triggeredCondition}\n" + "##########\n\n" + "${if backlog}" + "Last messages accounting for this alert:\n" + "${foreach backlog message}" + "${message}\n\n" + "${end}" + "${else}" + "<No backlog>\n" + "${end}" + "\n"; private final Engine templateEngine; private final NotificationService notificationService; private final NodeId nodeId; private Configuration pluginConfig; private final EmailConfiguration configuration; @Inject public FormattedEmailAlertSender(EmailConfiguration configuration, NotificationService notificationService, NodeId nodeId, Engine templateEngine) { this.configuration = requireNonNull(configuration, "configuration"); this.notificationService = requireNonNull(notificationService, "notificationService"); this.nodeId = requireNonNull(nodeId, "nodeId"); this.templateEngine = requireNonNull(templateEngine, "templateEngine"); } @Override public void initialize(Configuration configuration) { this.pluginConfig = configuration; } @VisibleForTesting String buildSubject(Stream stream, AlertCondition.CheckResult checkResult, List<Message> backlog) { final String template; if (pluginConfig == null || pluginConfig.getString("subject") == null) { template = "Graylog alert for stream: ${stream.title}: ${check_result.resultDescription}"; } else { template = pluginConfig.getString("subject"); } Map<String, Object> model = getModel(stream, checkResult, backlog); return templateEngine.transform(template, model); } @VisibleForTesting String buildBody(Stream stream, AlertCondition.CheckResult checkResult, List<Message> backlog) { final String template; if (pluginConfig == null || pluginConfig.getString("body") == null) { template = bodyTemplate; } else { template = pluginConfig.getString("body"); } Map<String, Object> model = getModel(stream, checkResult, backlog); return this.templateEngine.transform(template, model); } private Map<String, Object> getModel(Stream stream, AlertCondition.CheckResult checkResult, List<Message> backlog) { Map<String, Object> model = new HashMap<>(); model.put("stream", stream); model.put("check_result", checkResult); model.put("stream_url", buildStreamDetailsURL(configuration.getWebInterfaceUri(), checkResult, stream)); model.put("alertCondition", checkResult.getTriggeredCondition()); final List<Message> messages = firstNonNull(backlog, Collections.<Message>emptyList()); model.put("backlog", messages); model.put("backlog_size", messages.size()); return model; } private String buildStreamDetailsURL(URI baseUri, AlertCondition.CheckResult checkResult, Stream stream) { // Return an informational message if the web interface URL hasn't been set if (baseUri == null || isNullOrEmpty(baseUri.getHost())) { return "Please configure 'transport_email_web_interface_url' in your Graylog configuration file."; } int time = 5; if (checkResult.getTriggeredCondition().getParameters().get("time") != null) { time = (int) checkResult.getTriggeredCondition().getParameters().get("time"); } DateTime dateAlertEnd = checkResult.getTriggeredAt(); DateTime dateAlertStart = dateAlertEnd.minusMinutes(time); String alertStart = Tools.getISO8601String(dateAlertStart); String alertEnd = Tools.getISO8601String(dateAlertEnd); return baseUri + "/streams/" + stream.getId() + "/messages?rangetype=absolute&from=" + alertStart + "&to=" + alertEnd + "&q=*"; } @Override public void sendEmails(Stream stream, EmailRecipients recipients, AlertCondition.CheckResult checkResult) throws TransportConfigurationException, EmailException { sendEmails(stream, recipients, checkResult, null); } private void sendEmail(String emailAddress, Stream stream, AlertCondition.CheckResult checkResult, List<Message> backlog) throws TransportConfigurationException, EmailException { LOG.debug("Sending mail to " + emailAddress); if (!configuration.isEnabled()) { throw new TransportConfigurationException( "Email transport is not enabled in server configuration file!"); } final Email email = new SimpleEmail(); email.setCharset(EmailConstants.UTF_8); if (isNullOrEmpty(configuration.getHostname())) { throw new TransportConfigurationException( "No hostname configured for email transport while trying to send alert email!"); } else { email.setHostName(configuration.getHostname()); } email.setSmtpPort(configuration.getPort()); if (configuration.isUseSsl()) { email.setSslSmtpPort(Integer.toString(configuration.getPort())); } if (configuration.isUseAuth()) { email.setAuthenticator(new DefaultAuthenticator(Strings.nullToEmpty(configuration.getUsername()), Strings.nullToEmpty(configuration.getPassword()))); } email.setSSLOnConnect(configuration.isUseSsl()); email.setStartTLSEnabled(configuration.isUseTls()); if (pluginConfig != null && !isNullOrEmpty(pluginConfig.getString("sender"))) { email.setFrom(pluginConfig.getString("sender")); } else { email.setFrom(configuration.getFromEmail()); } email.setSubject(buildSubject(stream, checkResult, backlog)); email.setMsg(buildBody(stream, checkResult, backlog)); email.addTo(emailAddress); email.send(); } @Override public void sendEmails(Stream stream, EmailRecipients recipients, AlertCondition.CheckResult checkResult, List<Message> backlog) throws TransportConfigurationException, EmailException { if (!configuration.isEnabled()) { throw new TransportConfigurationException( "Email transport is not enabled in server configuration file!"); } if (recipients == null || recipients.isEmpty()) { throw new RuntimeException("Cannot send emails: empty recipient list."); } final Set<String> recipientsSet = recipients.getEmailRecipients(); if (recipientsSet.size() == 0) { final Notification notification = notificationService.buildNow().addNode(nodeId.toString()) .addType(Notification.Type.GENERIC).addSeverity(Notification.Severity.NORMAL) .addDetail("title", "Stream \"" + stream.getTitle() + "\" is alerted, but no recipients have been defined!") .addDetail("description", "To fix this, go to the alerting configuration of the stream and add at least one alert recipient."); notificationService.publishIfFirst(notification); } for (String email : recipientsSet) { sendEmail(email, stream, checkResult, backlog); } } }