feat: extract MySQL/MariaDB monitor to its own monitor-type and enable conditions support

2026-09-04 09:13:21 +00:00 · 2026-01-06 01:42:20 -05:00
parent 1d500bb88f
commit d825352410
5 changed files with 278 additions and 11 deletions
@@ -0,0 +1,118 @@
+const { MonitorType } = require("./monitor-type");
+const { log, UP } = require("../../src/util");
+const dayjs = require("dayjs");
+const mysql = require("mysql2");
+const { ConditionVariable } = require("../monitor-conditions/variables");
+const { defaultStringOperators } = require("../monitor-conditions/operators");
+const { ConditionExpressionGroup } = require("../monitor-conditions/expression");
+const { evaluateExpressionGroup } = require("../monitor-conditions/evaluator");
+
+class MysqlMonitorType extends MonitorType {
+    name = "mysql";
+
+    supportsConditions = true;
+    conditionVariables = [
+        new ConditionVariable("result", defaultStringOperators),
+    ];
+
+    /**
+     * @inheritdoc
+     */
+    async check(monitor, heartbeat, _server) {
+        let startTime = dayjs().valueOf();
+
+        let query = monitor.databaseQuery;
+        if (!query || (typeof query === "string" && query.trim() === "")) {
+            query = "SELECT 1";
+        }
+
+        // Use `radius_password` as `password` field for backwards compatibility
+        // TODO: rename `radius_password` to `password` later for general use
+        const password = monitor.radiusPassword;
+
+        let result;
+        try {
+            result = await this.mysqlQuery(monitor.databaseConnectionString, query, password);
+        } catch (error) {
+            log.error("mysql", "Database query failed:", error.message);
+            throw new Error(`Database connection/query failed: ${error.message}`);
+        } finally {
+            heartbeat.ping = dayjs().valueOf() - startTime;
+        }
+
+        const conditions = ConditionExpressionGroup.fromMonitor(monitor);
+        const handleConditions = (data) =>
+            conditions ? evaluateExpressionGroup(conditions, data) : true;
+
+        // Since result is now a single value, pass it directly to conditions
+        const conditionsResult = handleConditions({ result: String(result) });
+
+        if (!conditionsResult) {
+            throw new Error(`Query result did not meet the specified conditions (${result})`);
+        }
+
+        heartbeat.msg = "";
+        heartbeat.status = UP;
+    }
+
+    /**
+     * Run a query on MySQL/MariaDB
+     * @param {string} connectionString The database connection string
+     * @param {string} query The query to execute
+     * @param {string} password Optional password override
+     * @returns {Promise<any>} Single value from the first column of the first row
+     */
+    mysqlQuery(connectionString, query, password = undefined) {
+        return new Promise((resolve, reject) => {
+            const connection = mysql.createConnection({
+                uri: connectionString,
+                password
+            });
+
+            connection.on("error", (err) => {
+                reject(err);
+            });
+
+            connection.query(query, (err, res) => {
+                try {
+                    connection.end();
+                } catch (_) {
+                    connection.destroy();
+                }
+
+                if (err) {
+                    reject(err);
+                    return;
+                }
+
+                // Check if we have results
+                if (!Array.isArray(res) || res.length === 0) {
+                    reject(new Error("Query returned no results"));
+                    return;
+                }
+
+                // Check if we have multiple rows
+                if (res.length > 1) {
+                    reject(new Error("Multiple values were found, expected only one value"));
+                    return;
+                }
+
+                const firstRow = res[0];
+                const columnNames = Object.keys(firstRow);
+
+                // Check if we have multiple columns
+                if (columnNames.length > 1) {
+                    reject(new Error("Multiple columns were found, expected only one value"));
+                    return;
+                }
+
+                // Return the single value from the first (and only) column
+                resolve(firstRow[columnNames[0]]);
+            });
+        });
+    }
+}
+
+module.exports = {
+    MysqlMonitorType,
+};