workadventure/uploader/src/Services/GaugeManager.ts

import {Counter, Gauge} from "prom-client";

//this class should manage all the custom metrics used by prometheus
class GaugeManager {
    private nbClientsGauge: Gauge<string>;
    private nbClientsPerRoomGauge: Gauge<string>;
    private nbGroupsPerRoomGauge: Gauge<string>;
    private nbGroupsPerRoomCounter: Counter<string>;

    constructor() {
        this.nbClientsGauge = new Gauge({
            name: 'workadventure_nb_sockets',
            help: 'Number of connected sockets',
            labelNames: [ ]
        });
        this.nbClientsPerRoomGauge = new Gauge({
            name: 'workadventure_nb_clients_per_room',
            help: 'Number of clients per room',
            labelNames: [ 'room' ]
        });

        this.nbGroupsPerRoomCounter = new Counter({
            name: 'workadventure_counter_groups_per_room',
            help: 'Counter of groups per room',
            labelNames: [ 'room' ]
        });
        this.nbGroupsPerRoomGauge = new Gauge({
            name: 'workadventure_nb_groups_per_room',
            help: 'Number of groups per room',
            labelNames: [ 'room' ]
        });
    }

    incNbClientPerRoomGauge(roomId: string): void {
        this.nbClientsGauge.inc();
        this.nbClientsPerRoomGauge.inc({ room: roomId });
    }

    decNbClientPerRoomGauge(roomId: string): void {
        this.nbClientsGauge.dec();
        this.nbClientsPerRoomGauge.dec({ room: roomId });
    }

    incNbGroupsPerRoomGauge(roomId: string): void {
        this.nbGroupsPerRoomCounter.inc({ room: roomId })
        this.nbGroupsPerRoomGauge.inc({ room: roomId })
    }
    
    decNbGroupsPerRoomGauge(roomId: string): void {
        this.nbGroupsPerRoomGauge.dec({ room: roomId })
    }
}

export const gaugeManager = new GaugeManager();