feat: Add SNMP Monitor

db/knex_migrations/2024-04-26-0000-snmp-monitor.js

@@ -0,0 +1,20 @@
+exports.up = function (knex) {
+    return knex.schema
+        .alterTable("monitor", function (table) {
+            table.string("snmp_community_string", 255).defaultTo("public");
+            table.string("snmp_oid").defaultTo(null);
+            table.enum("snmp_version", [ "1", "2c", "3" ]).defaultTo("2c");
+            table.float("snmp_control_value").defaultTo(null);
+            table.string("snmp_condition").defaultTo(null);
+        });
+};
+
+exports.down = function (knex) {
+    return knex.schema.alterTable("monitor", function (table) {
+        table.dropColumn("snmp_community_string");
+        table.dropColumn("snmp_oid");
+        table.dropColumn("snmp_version");
+        table.dropColumn("snmp_control_value");
+        table.dropColumn("snmp_condition");
+    });
+};

package.json

@@ -119,6 +119,7 @@
         "mssql": "~8.1.4",
         "mysql2": "~3.9.6",
         "nanoid": "~3.3.4",
+        "net-snmp": "^3.11.2",
         "node-cloudflared-tunnel": "~1.0.9",
         "node-radius-client": "~1.0.0",
         "nodemailer": "~6.9.13",

server/model/monitor.js

@@ -161,6 +161,10 @@ class Monitor extends BeanModel {
             kafkaProducerMessage: this.kafkaProducerMessage,
             screenshot,
             remote_browser: this.remote_browser,
+            snmpOid: this.snmpOid,
+            snmpCondition: this.snmpCondition,
+            snmpControlValue: this.snmpControlValue,
+            snmpVersion: this.snmpVersion,
         };
 
         if (includeSensitiveData) {
@@ -190,6 +194,7 @@ class Monitor extends BeanModel {
                 tlsCert: this.tlsCert,
                 tlsKey: this.tlsKey,
                 kafkaProducerSaslOptions: JSON.parse(this.kafkaProducerSaslOptions),
+                snmpCommunityString: this.snmpCommunityString,
             };
         }
 

server/monitor-types/snmp.js

@@ -0,0 +1,93 @@
+const { MonitorType } = require("./monitor-type");
+const { UP, DOWN, log } = require("../../src/util");
+const snmp = require("net-snmp");
+
+class SNMPMonitorType extends MonitorType {
+    name = "snmp";
+
+    /**
+     * @inheritdoc
+     */
+    async check(monitor, heartbeat, _server) {
+
+        const options = {
+            port: monitor.port || "161",
+            retries: monitor.maxretries,
+            timeout: monitor.timeout * 1000,
+            version: snmp.Version[monitor.snmpVersion],
+        };
+
+        let session;
+        try {
+            session = snmp.createSession(monitor.hostname, monitor.snmpCommunityString, options);
+
+            // Handle errors during session creation
+            session.on("error", (error) => {
+                throw new Error(`Error creating SNMP session: ${error.message}`);
+            });
+
+            const varbinds = await new Promise((resolve, reject) => {
+                session.get([ monitor.snmpOid ], (error, varbinds) => {
+                    if (error) {
+                        reject(error);
+                    } else {
+                        resolve(varbinds);
+                    }
+                });
+            });
+            log.debug("monitor", `SNMP: Received varbinds (Type: ${snmp.ObjectType[varbinds[0].type]} Value: ${varbinds[0].value}`);
+
+            if (varbinds.length === 0) {
+                throw new Error(`No varbinds returned from SNMP session (OID: ${monitor.snmpOid})`);
+            }
+
+            if (varbinds[0].type === snmp.ObjectType.NoSuchInstance) {
+                throw new Error(`The SNMP query returned that no instance exists for OID ${monitor.snmpOid}`);
+            }
+
+            // We restrict querying to one OID per monitor, therefore `varbinds[0]` will always contain the value we're interested in.
+            const value = varbinds[0].value;
+
+            // Check if inputs are numeric. If not, re-parse as strings. This ensures comparisons are handled correctly.
+            let snmpValue = isNaN(value) ? value.toString() : parseFloat(value);
+            let snmpControlValue = isNaN(monitor.snmpControlValue) ? monitor.snmpControlValue.toString() : parseFloat(monitor.snmpControlValue);
+
+            switch (monitor.snmpCondition) {
+                case ">":
+                    heartbeat.status = snmpValue > snmpControlValue ? UP : DOWN;
+                    break;
+                case ">=":
+                    heartbeat.status = snmpValue >= snmpControlValue ? UP : DOWN;
+                    break;
+                case "<":
+                    heartbeat.status = snmpValue < snmpControlValue ? UP : DOWN;
+                    break;
+                case "<=":
+                    heartbeat.status = snmpValue <= snmpControlValue ? UP : DOWN;
+                    break;
+                case "==":
+                    heartbeat.status = snmpValue.toString() === snmpControlValue.toString() ? UP : DOWN;
+                    break;
+                case "contains":
+                    heartbeat.status = snmpValue.toString().includes(snmpControlValue.toString()) ? UP : DOWN;
+                    break;
+                default:
+                    throw new Error(`Invalid condition ${monitor.snmpCondition}`);
+            }
+            heartbeat.msg = "SNMP value " + (heartbeat.status ? "passes" : "does not pass") + ` comparison: ${value.toString()} ${monitor.snmpCondition} ${snmpControlValue}`;
+
+        } catch (err) {
+            heartbeat.status = DOWN;
+            heartbeat.msg = `SNMP Error: ${err.message}`;
+        } finally {
+            if (session) {
+                session.close();
+            }
+        }
+    }
+
+}
+
+module.exports = {
+    SNMPMonitorType,
+};

server/server.js

@@ -830,6 +830,12 @@ let needSetup = false;
                     monitor.kafkaProducerAllowAutoTopicCreation;
                 bean.gamedigGivenPortOnly = monitor.gamedigGivenPortOnly;
                 bean.remote_browser = monitor.remote_browser;
+                bean.snmpVersion = monitor.snmpVersion;
+                bean.snmpCommunityString = monitor.snmpCommunityString;
+                bean.snmpOid = monitor.snmpOid;
+                bean.snmpCondition = monitor.snmpCondition;
+                bean.snmpControlValue = monitor.snmpControlValue;
+                bean.timeout = monitor.timeout;
 
                 bean.validate();
 

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["snmp"] = new SNMPMonitorType();
 
         // Allow all CORS origins (polling) in development
         let cors = undefined;
@@ -516,3 +517,4 @@ 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 { SNMPMonitorType } = require("./monitor-types/snmp");

src/lang/en.json

@@ -921,5 +921,13 @@
     "Allow Long SMS": "Allow Long SMS",
     "cellsyntSplitLongMessages": "Split long messages into up to 6 parts. 153 x 6 = 918 characters.",
     "max 15 digits": "max 15 digits",
-    "max 11 alphanumeric characters": "max 11 alphanumeric characters"
+    "max 11 alphanumeric characters": "max 11 alphanumeric characters",
+    "Community String": "Community String",
+    "snmpCommunityStringHelptext": "This string functions as a password to authenticate and control access to SNMP-enabled devices. Match it with your SNMP device's configuration.",
+    "OID (Object Identifier)": "OID (Object Identifier)",
+    "snmpOIDHelptext": "Enter the OID for the sensor or status you want to monitor. Use network management tools like MIB browsers or SNMP software if you're unsure about the OID.",
+    "Condition": "Condition",
+    "Control Value": "Control Value",
+    "SNMP Version": "SNMP Version",
+    "Please enter a valid OID.": "Please enter a valid OID."
 }

src/pages/EditMonitor.vue

@@ -24,6 +24,9 @@
                                         <option value="ping">
                                             Ping
                                         </option>
+                                        <option value="snmp">
+                                            SNMP
+                                        </option>
                                         <option value="keyword">
                                             HTTP(s) - {{ $t("Keyword") }}
                                         </option>
@@ -246,19 +249,69 @@
                             </template>
 
                             <!-- Hostname -->
-                            <!-- TCP Port / Ping / DNS / Steam / MQTT / Radius / Tailscale Ping 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'" class="my-3">
+                            <!-- 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">
                                 <label for="hostname" class="form-label">{{ $t("Hostname") }}</label>
                                 <input id="hostname" v-model="monitor.hostname" type="text" class="form-control" :pattern="`${monitor.type === 'mqtt' ? mqttIpOrHostnameRegexPattern : ipOrHostnameRegexPattern}`" required>
                             </div>
 
                             <!-- Port -->
-                            <!-- For TCP Port / Steam / MQTT / Radius Type -->
-                            <div v-if="monitor.type === 'port' || monitor.type === 'steam' || monitor.type === 'gamedig' || monitor.type === 'mqtt' || monitor.type === 'radius'" class="my-3">
+                            <!-- 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">
                                 <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>
 
+                            <!-- SNMP Monitor Type -->
+                            <div v-if="monitor.type === 'snmp'" class="my-3">
+                                <label for="snmp_community_string" class="form-label">{{ $t("Community String") }}</label>
+                                <!-- TODO: Rename monitor.radiusPassword to monitor.password for general use -->
+                                <HiddenInput id="snmp_community_string" v-model="monitor.radiusPassword" autocomplete="false" required="true" placeholder="public"></HiddenInput>
+
+                                <div class="form-text">{{ $t('snmpCommunityStringHelptext')
+ }}</div>
+                            </div>
+
+                            <div v-if="monitor.type === 'snmp'" class="my-3">
+                                <label for="snmp_oid" class="form-label">{{ $t("OID (Object Identifier)") }}</label>
+                                <input id="snmp_oid" v-model="monitor.snmpOid" :title="$t('Please enter a valid OID.') + ' ' + $t('Example:', ['1.3.6.1.4.1.9.6.1.101'])" type="text" class="form-control" pattern="^([0-2])((\.0)|(\.[1-9][0-9]*))*$" placeholder="1.3.6.1.4.1.9.6.1.101" required>
+                                <div class="form-text">{{ 
+$t('snmpOIDHelptext') }}</div>
+                            </div>
+
+                            <div v-if="monitor.type === 'snmp'" class="my-3">
+                                <div class="d-flex align-items-start">
+                                    <div class="me-2">
+                                        <label for="snmp_condition" class="form-label">{{ $t("Condition") }}</label>
+                                        <select id="snmp_condition" v-model="monitor.snmpCondition" class="form-select me-3" required>
+                                            <option value=">">&gt;</option>
+                                            <option value=">=">&gt;=</option>
+                                            <option value="<">&lt;</option>
+                                            <option value="<=">&lt;=</option>
+                                            <option value="==">==</option>
+                                            <option value="contains">contains</option>
+                                        </select>
+                                    </div>
+                                    <div class="flex-grow-1">
+                                        <label for="snmp_control_value" class="form-label">{{ $t("Control Value") }}</label>
+                                        <input v-if="monitor.snmpCondition !== 'contains' && monitor.snmpCondition !== '=='" id="snmp_control_value" v-model="monitor.snmpControlValue" type="number" class="form-control" required step=".01">
+                                        <input v-else id="snmp_control_value" v-model="monitor.snmpControlValue" type="text" class="form-control" required>
+                                    </div>
+                                </div>
+                            </div>
+
+                            <div v-if="monitor.type === 'snmp'" class="my-3">
+                                <label for="snmp_version" class="form-label">{{ $t("SNMP Version") }}</label>
+                                <select id="snmp_version" v-model="monitor.snmpVersion" class="form-select">
+                                    <option value="1">
+                                        SNMPv1
+                                    </option>
+                                    <option value="2c">
+                                        SNMPv2c
+                                    </option>
+                                </select>
+                            </div>
+
                             <!-- DNS Resolver Server -->
                             <!-- For DNS Type -->
                             <template v-if="monitor.type === 'dns'">
@@ -456,8 +509,8 @@
                                 <input id="retry-interval" v-model="monitor.retryInterval" type="number" class="form-control" required :min="minInterval" step="1">
                             </div>
 
-                            <!-- Timeout: HTTP / Keyword only -->
-                            <div v-if="monitor.type === 'http' || monitor.type === 'keyword' || monitor.type === 'json-query'" class="my-3">
+                            <!-- Timeout: HTTP / Keyword / SNMP only -->
+                            <div v-if="monitor.type === 'http' || monitor.type === 'keyword' || monitor.type === 'json-query' || monitor.type === 'snmp'" class="my-3">
                                 <label for="timeout" class="form-label">{{ $t("Request Timeout") }} ({{ $t("timeoutAfter", [ monitor.timeout || clampTimeout(monitor.interval) ]) }})</label>
                                 <input id="timeout" v-model="monitor.timeout" type="number" class="form-control" required min="0" step="0.1">
                             </div>
@@ -919,7 +972,6 @@
     retryInterval: 60,
     resendInterval: 0,
     maxretries: 0,
-    timeout: 48,
     notificationIDList: {},
     ignoreTls: false,
     upsideDown: false,
@@ -1131,8 +1183,8 @@
             // Only groups, not itself, not a decendant
             result = result.filter(
                 monitor => monitor.type === "group" &&
-				monitor.id !== this.monitor.id &&
-				!this.monitor.childrenIDs?.includes(monitor.id)
+                monitor.id !== this.monitor.id &&
+                !this.monitor.childrenIDs?.includes(monitor.id)
             );
 
             // Filter result by active state, weight and alphabetical
@@ -1264,11 +1316,25 @@
                     this.monitor.port = "53";
                 } else if (this.monitor.type === "radius") {
                     this.monitor.port = "1812";
+                } else if (this.monitor.type === "snmp") {
+                    this.monitor.port = "161";
                 } else {
                     this.monitor.port = undefined;
                 }
             }
 
+            if (this.monitor.type === "snmp") {
+                // snmp is not expected to be executed via the internet => we can choose a lower default timeout
+                this.monitor.timeout = 5;
+            } else {
+                this.monitor.timeout = 48;
+            }
+
+            // Set default SNMP version
+            if (!this.monitor.snmpVersion) {
+                this.monitor.snmpVersion = "1";
+            }
+
             // Get the game list from server
             if (this.monitor.type === "gamedig") {
                 this.$root.getSocket().emit("getGameList", (res) => {