feat: Add 'local service' monitor type

This adds a new monitor type to check local services by executing a shell command. It also includes fixes for Prometheus errors when adding new tags and for the UI not updating when tags are changed.
2026-09-04 17:23:21 +00:00 · 2025-12-14 16:39:00 +01:00
parent 883083f5c3
commit 7461bd296f
8 changed files with 225 additions and 39 deletions
@@ -0,0 +1,62 @@
+const { MonitorType } = require("./monitor-type");
+const { exec } = require("child_process");
+const { DOWN, UP, log, evaluateJsonQuery } = require("../../src/util");
+
+class LocalServiceMonitorType extends MonitorType {
+    name = "local-service";
+    description = "Checks if a local service is running by executing a command.";
+
+    async check(monitor, heartbeat, server) {
+        return new Promise((resolve, reject) => {
+            exec(monitor.local_service_command, async (error, stdout, stderr) => {
+                if (error) {
+                    heartbeat.status = DOWN;
+                    heartbeat.msg = `Error executing command: ${error.message}`;
+                    reject(new Error(heartbeat.msg));
+                    return;
+                }
+
+                const output = stdout.trim();
+
+                if (monitor.local_service_check_type === "keyword") {
+                    if (monitor.local_service_expected_output) {
+                        if (output.includes(monitor.local_service_expected_output)) {
+                            heartbeat.status = UP;
+                            heartbeat.msg = `OK - Output contains "${monitor.local_service_expected_output}"`;
+                            resolve();
+                        } else {
+                            heartbeat.status = DOWN;
+                            heartbeat.msg = `Output did not contain "${monitor.local_service_expected_output}"`;
+                            reject(new Error(heartbeat.msg));
+                        }
+                    } else {
+                        heartbeat.status = UP;
+                        heartbeat.msg = "OK - Command executed successfully";
+                        resolve();
+                    }
+                } else if (monitor.local_service_check_type === "json-query") {
+                    try {
+                        const data = JSON.parse(output);
+                        const { status, response } = await evaluateJsonQuery(data, monitor.jsonPath, monitor.jsonPathOperator, monitor.expectedValue);
+
+                        if (status) {
+                            heartbeat.status = UP;
+                            heartbeat.msg = `JSON query passes (comparing ${response} ${monitor.jsonPathOperator} ${monitor.expectedValue})`;
+                            resolve();
+                        } else {
+                            throw new Error(`JSON query does not pass (comparing ${response} ${monitor.jsonPathOperator} ${monitor.expectedValue})`);
+                        }
+                    } catch (e) {
+                        heartbeat.status = DOWN;
+                        heartbeat.msg = e.message;
+                        reject(e);
+                    }
+                }
+            });
+        });
+    }
+}
+
+module.exports = {
+    LocalServiceMonitorType,
+};