Add Prometheus metrics endpoint

openapi.yaml

@@ -1350,6 +1350,18 @@ paths:
                 type: array
                 items:
                   $ref: '#/components/schemas/Statistics'
+  /metrics:
+    get:
+      summary: Fetch Prometheus Metrics
+      tags:
+        - Statistics
+      responses:
+        '200':
+          description: OK
+          content:
+            text/plain:
+              schema:
+                type: string
   /calendars:
     get:
       summary: Fetch a list of Calendars

src/main/java/org/traccar/api/resource/MetricsResource.java

@@ -0,0 +1,55 @@
+package org.traccar.api.resource;
+
+import jakarta.annotation.security.PermitAll;
+import jakarta.inject.Inject;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
+import org.traccar.api.BaseResource;
+import org.traccar.database.StatisticsManager;
+import org.traccar.model.Statistics;
+
+@Path("metrics")
+@Produces(MediaType.TEXT_PLAIN)
+public class MetricsResource extends BaseResource {
+
+    @Inject
+    private StatisticsManager statisticsManager;
+
+    @PermitAll
+    @GET
+    public String get() {
+        Statistics statistics = statisticsManager.getStatistics();
+        StringBuilder sb = new StringBuilder();
+        sb.append("# TYPE traccar_requests_total counter\n");
+        sb.append("traccar_requests_total ").append(statistics.getRequests()).append('\n');
+        sb.append("# TYPE traccar_messages_received_total counter\n");
+        sb.append("traccar_messages_received_total ").append(statistics.getMessagesReceived()).append('\n');
+        sb.append("# TYPE traccar_messages_stored_total counter\n");
+        sb.append("traccar_messages_stored_total ").append(statistics.getMessagesStored()).append('\n');
+        sb.append("# TYPE traccar_mail_sent_total counter\n");
+        sb.append("traccar_mail_sent_total ").append(statistics.getMailSent()).append('\n');
+        sb.append("# TYPE traccar_sms_sent_total counter\n");
+        sb.append("traccar_sms_sent_total ").append(statistics.getSmsSent()).append('\n');
+        sb.append("# TYPE traccar_geocoder_requests_total counter\n");
+        sb.append("traccar_geocoder_requests_total ").append(statistics.getGeocoderRequests()).append('\n');
+        sb.append("# TYPE traccar_geolocation_requests_total counter\n");
+        sb.append("traccar_geolocation_requests_total ").append(statistics.getGeolocationRequests()).append('\n');
+        sb.append("# TYPE traccar_active_users gauge\n");
+        sb.append("traccar_active_users ").append(statistics.getActiveUsers()).append('\n');
+        sb.append("# TYPE traccar_active_devices gauge\n");
+        sb.append("traccar_active_devices ").append(statistics.getActiveDevices()).append('\n');
+        if (statistics.getProtocols() != null) {
+            sb.append("# TYPE traccar_protocol_devices gauge\n");
+            for (var entry : statistics.getProtocols().entrySet()) {
+                sb.append("traccar_protocol_devices{protocol=\"")
+                        .append(entry.getKey())
+                        .append("\"} ")
+                        .append(entry.getValue())
+                        .append('\n');
+            }
+        }
+        return sb.toString();
+    }
+}

src/main/java/org/traccar/database/StatisticsManager.java

@@ -204,4 +204,27 @@ public class StatisticsManager {
         geolocationRequests += 1;
     }
 
+    public synchronized Statistics getStatistics() {
+        checkSplit();
+        Statistics statistics = new Statistics();
+        statistics.setCaptureTime(new Date());
+        statistics.setActiveUsers(users.size());
+        statistics.setActiveDevices(deviceProtocols.size());
+        statistics.setRequests(requests);
+        statistics.setMessagesReceived(messagesReceived);
+        statistics.setMessagesStored(messagesStored);
+        statistics.setMailSent(mailSent);
+        statistics.setSmsSent(smsSent);
+        statistics.setGeocoderRequests(geocoderRequests);
+        statistics.setGeolocationRequests(geolocationRequests);
+        if (!deviceProtocols.isEmpty()) {
+            Map<String, Integer> protocols = new HashMap<>();
+            for (String protocol : deviceProtocols.values()) {
+                protocols.merge(protocol, (Integer) 1, Integer::sum);
+            }
+            statistics.setProtocols(protocols);
+        }
+        return statistics;
+    }
+
 }