added SMTP monitor (#5489)

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

Author: koehn

db/knex_migrations/2025-01-01-0000-add-smtp.js

@@ -0,0 +1,12 @@
+exports.up = function (knex) {
+    return knex.schema
+        .alterTable("monitor", function (table) {
+            table.string("smtp_security").defaultTo(null);
+        });
+};
+
+exports.down = function (knex) {
+    return knex.schema.alterTable("monitor", function (table) {
+        table.dropColumn("smtp_security");
+    });
+};

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");

src/lang/en.json

@@ -1074,6 +1074,7 @@
     "rabbitmqHelpText": "To use the monitor, you will need to enable the Management Plugin in your RabbitMQ setup. For more information, please consult the {rabitmq_documentation}.",
     "SendGrid API Key": "SendGrid API Key",
     "Separate multiple email addresses with commas": "Separate multiple email addresses with commas",
+    "smtpHelpText": "“SMTPS” tests that SMTP/TLS is working; “Ignore TLS” connects over plaintext; “STARTTLS” connects, issues a STARTTLS command and verifies the server certificate. None of these send an email.",
     "Custom URL": "Custom URL",
     "customUrlDescription": "Will be used as the clickable URL instead of the monitor's one.",
     "OneChatAccessToken": "OneChat Access Token",

src/pages/EditMonitor.vue

@@ -24,6 +24,9 @@
                                         <option value="ping">
                                             Ping
                                         </option>
+                                        <option value="smtp">
+                                            SMTP
+                                        </option>
                                         <option value="snmp">
                                             SNMP
                                         </option>
@@ -281,8 +284,8 @@
                             </template>
 
                             <!-- Hostname -->
-                            <!-- TCP Port / Ping / DNS / Steam / MQTT / Radius / Tailscale Ping / SNMP only -->
-                            <div v-if="monitor.type === 'port' || monitor.type === 'ping' || monitor.type === 'dns' || monitor.type === 'steam' || monitor.type === 'gamedig' || monitor.type === 'mqtt' || monitor.type === 'radius' || monitor.type === 'tailscale-ping' || monitor.type === 'snmp'" class="my-3">
+                            <!-- TCP Port / Ping / DNS / Steam / MQTT / Radius / Tailscale Ping / SNMP / SMTP only -->
+                            <div v-if="monitor.type === 'port' || monitor.type === 'ping' || monitor.type === 'dns' || monitor.type === 'steam' || monitor.type === 'gamedig' || monitor.type === 'mqtt' || monitor.type === 'radius' || monitor.type === 'tailscale-ping' || monitor.type === 'smtp' || monitor.type === 'snmp'" class="my-3">
                                 <label for="hostname" class="form-label">{{ $t("Hostname") }}</label>
                                 <input
                                     id="hostname"
@@ -297,7 +300,7 @@
 
                             <!-- Port -->
                             <!-- For TCP Port / Steam / MQTT / Radius Type / SNMP -->
-                            <div v-if="monitor.type === 'port' || monitor.type === 'steam' || monitor.type === 'gamedig' || monitor.type === 'mqtt' || monitor.type === 'radius' || monitor.type === 'snmp'" class="my-3">
+                            <div v-if="monitor.type === 'port' || monitor.type === 'steam' || monitor.type === 'gamedig' || monitor.type === 'mqtt' || monitor.type === 'radius' || monitor.type === 'smtp' || monitor.type === 'snmp'" class="my-3">
                                 <label for="port" class="form-label">{{ $t("Port") }}</label>
                                 <input id="port" v-model="monitor.port" type="number" class="form-control" required min="0" max="65535" step="1">
                             </div>
@@ -329,6 +332,18 @@
                                 </select>
                             </div>
 
+                            <div v-if="monitor.type === 'smtp'" class="my-3">
+                                <label for="smtp_security" class="form-label">{{ $t("SMTP Security") }}</label>
+                                <select id="smtp_security" v-model="monitor.smtpSecurity" class="form-select">
+                                    <option value="secure">SMTPS</option>
+                                    <option value="nostarttls">Ignore STARTTLS</option>
+                                    <option value="starttls">Use STARTTLS</option>
+                                </select>
+                                <div class="form-text">
+                                    {{ $t("smtpHelpText") }}
+                                </div>
+                            </div>
+
                             <!-- Json Query -->
                             <!-- For Json Query / SNMP -->
                             <div v-if="monitor.type === 'json-query' || monitor.type === 'snmp'" class="my-3">