SNMP Initial Commits

This commit introduces a new SNMP monitor feature to the application, allowing users to monitor devices using SNMP (Simple Network Management Protocol).

server/monitor-types/snmp.js

@@ -0,0 +1,69 @@
+const { MonitorType } = require("./monitor-type");
+const { UP, DOWN } = require("../../src/util");
+const snmp = require("snmp-native");
+
+class SNMPMonitorType extends MonitorType {
+    name = "snmp";
+
+    /**
+     * Checks the SNMP value against the condition and control value.
+     * @param {object} monitor The monitor object associated with the check.
+     * @param {object} heartbeat The heartbeat object to update.
+     * @param {object} _server Unused server object.
+     */
+    async check(monitor, heartbeat, _server) {
+        try {
+            const session = new snmp.Session({ host: monitor.ipAddress, community: monitor.snmpCommunityString, version: monitor.snmpVersion });
+
+            session.get({ oid: monitor.snmpOid }, (err, varbinds) => {
+                if (err) {
+                    heartbeat.status = DOWN;
+                    heartbeat.msg = `Error: ${err.message}`;
+                    return;
+                }
+
+                // Assuming only one varbind is returned
+                const value = varbinds[0].value;
+
+                // Convert value to appropriate type based on SNMP type (assuming it's integer or string for simplicity)
+                const numericValue = parseInt(value);
+                const stringValue = value.toString();
+
+                // Check against condition and control value
+                switch (monitor.snmpCondition) {
+                    case '>':
+                        heartbeat.status = numericValue > monitor.snmpControlValue ? UP : DOWN;
+                        break;
+                    case '>=':
+                        heartbeat.status = numericValue >= monitor.snmpControlValue ? UP : DOWN;
+                        break;
+                    case '<':
+                        heartbeat.status = numericValue < monitor.snmpControlValue ? UP : DOWN;
+                        break;
+                    case '<=':
+                        heartbeat.status = numericValue <= monitor.snmpControlValue ? UP : DOWN;
+                        break;
+                    case '==':
+                        heartbeat.status = value === monitor.snmpControlValue ? UP : DOWN;
+                        break;
+                    case 'contains':
+                        heartbeat.status = stringValue.includes(monitor.snmpControlValue) ? UP : DOWN;
+                        break;
+                    default:
+                        heartbeat.status = DOWN;
+                        heartbeat.msg = `Invalid condition: ${monitor.snmpCondition}`;
+                }
+
+                session.close();
+            });
+        } catch (err) {
+            heartbeat.status = DOWN;
+            heartbeat.msg = `Error: ${err.message}`;
+        }
+    }
+
+}
+
+module.exports = {
+    SNMPMonitorType,
+};