Fix: Remove Prom. metrics on delete monitor

server/model/monitor.js

@@ -468,6 +468,11 @@ class Monitor extends BeanModel {
         this.isStop = true;
     }
 
+    onDelete() {
+        let prometheus = new Prometheus(this);
+        prometheus.remove();
+    }
+
     /**
      * Helper Method:
      * returns URL object for further usage

server/prometheus.js

@@ -84,6 +84,16 @@ class Prometheus {
         }
     }
 
+    remove() {
+        try {
+            monitor_cert_days_remaining.remove(this.monitorLabelValues);
+            monitor_cert_is_valid.remove(this.monitorLabelValues);
+            monitor_response_time.remove(this.monitorLabelValues);
+            monitor_status.remove(this.monitorLabelValues);
+        } catch (e) {
+            console.error(e);
+        }
+    }
 }
 
 module.exports = {

server/server.js

@@ -733,6 +733,7 @@ exports.entryPage = "dashboard";
 
                 if (monitorID in monitorList) {
                     monitorList[monitorID].stop();
+                    monitorList[monitorID].onDelete();
                     delete monitorList[monitorID];
                 }