added SMTP monitor (#5489)

Co-authored-by: Frank Elsinga <frank@elsinga.de>

server/model/monitor.js

@@ -153,6 +153,7 @@ class Monitor extends BeanModel {
             snmpOid: this.snmpOid,
             jsonPathOperator: this.jsonPathOperator,
             snmpVersion: this.snmpVersion,
+            smtpSecurity: this.smtpSecurity,
             rabbitmqNodes: JSON.parse(this.rabbitmqNodes),
             conditions: JSON.parse(this.conditions),
         };

server/monitor-types/smtp.js

@@ -0,0 +1,35 @@
+const { MonitorType } = require("./monitor-type");
+const { UP } = require("../../src/util");
+const nodemailer = require("nodemailer");
+
+class SMTPMonitorType extends MonitorType {
+    name = "smtp";
+
+    /**
+     * @inheritdoc
+     */
+    async check(monitor, heartbeat, _server) {
+        let options = {
+            port: monitor.port || 25,
+            host: monitor.hostname,
+            secure: monitor.smtpSecurity === "secure", // use SMTPS (not STARTTLS)
+            ignoreTLS: monitor.smtpSecurity === "nostarttls", // don't use STARTTLS even if it's available
+            requireTLS: monitor.smtpSecurity === "starttls", // use STARTTLS or fail
+        };
+        let transporter = nodemailer.createTransport(options);
+        try {
+            await transporter.verify();
+
+            heartbeat.status = UP;
+            heartbeat.msg = "SMTP connection verifies successfully";
+        } catch (e) {
+            throw new Error(`SMTP connection doesn't verify: ${e}`);
+        } finally {
+            transporter.close();
+        }
+    }
+}
+
+module.exports = {
+    SMTPMonitorType,
+};

server/server.js

@@ -866,6 +866,7 @@ let needSetup = false;
                     monitor.kafkaProducerAllowAutoTopicCreation;
                 bean.gamedigGivenPortOnly = monitor.gamedigGivenPortOnly;
                 bean.remote_browser = monitor.remote_browser;
+                bean.smtpSecurity = monitor.smtpSecurity;
                 bean.snmpVersion = monitor.snmpVersion;
                 bean.snmpOid = monitor.snmpOid;
                 bean.jsonPathOperator = monitor.jsonPathOperator;

server/uptime-kuma-server.js

@@ -113,6 +113,7 @@ class UptimeKumaServer {
         UptimeKumaServer.monitorTypeList["tailscale-ping"] = new TailscalePing();
         UptimeKumaServer.monitorTypeList["dns"] = new DnsMonitorType();
         UptimeKumaServer.monitorTypeList["mqtt"] = new MqttMonitorType();
+        UptimeKumaServer.monitorTypeList["smtp"] = new SMTPMonitorType();
         UptimeKumaServer.monitorTypeList["group"] = new GroupMonitorType();
         UptimeKumaServer.monitorTypeList["snmp"] = new SNMPMonitorType();
         UptimeKumaServer.monitorTypeList["mongodb"] = new MongodbMonitorType();
@@ -552,6 +553,7 @@ const { RealBrowserMonitorType } = require("./monitor-types/real-browser-monitor
 const { TailscalePing } = require("./monitor-types/tailscale-ping");
 const { DnsMonitorType } = require("./monitor-types/dns");
 const { MqttMonitorType } = require("./monitor-types/mqtt");
+const { SMTPMonitorType } = require("./monitor-types/smtp");
 const { GroupMonitorType } = require("./monitor-types/group");
 const { SNMPMonitorType } = require("./monitor-types/snmp");
 const { MongodbMonitorType } = require("./monitor-types/mongodb");