BC-8053 added metrics endpoint

pom.xml

@@ -12,7 +12,7 @@
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <quarkus.platform.artifact-id>quarkus-bom</quarkus.platform.artifact-id>
     <quarkus.platform.group-id>io.quarkus.platform</quarkus.platform.group-id>
-    <quarkus.platform.version>3.13.2</quarkus.platform.version>
+    <quarkus.platform.version>3.14.2</quarkus.platform.version>
     <skipITs>true</skipITs>
     <surefire-plugin.version>3.4.0</surefire-plugin.version>
     <testcontainers.version>1.20.1</testcontainers.version>
@@ -39,6 +39,10 @@
       <groupId>io.quarkus</groupId>
       <artifactId>quarkus-scheduler</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.quarkus</groupId>
+      <artifactId>quarkus-micrometer-registry-prometheus</artifactId>
+    </dependency>
     <dependency>
       <groupId>io.quarkus</groupId>
       <artifactId>quarkus-kubernetes-client</artifactId>

src/main/java/de/svs/Namespace.java

@@ -6,6 +6,7 @@
 import org.bson.types.ObjectId;
 
 import java.time.Instant;
+import java.time.LocalDateTime;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -32,6 +33,15 @@ public static List<Namespace> findByActivatedUntilOlderThan(Instant activatedUnt
         return find("activatedUntil < ?1", activatedUntil).list();
     }
 
+    public static long countActiveNamespaces() {
+        LocalDateTime now = LocalDateTime.now();
+        return count("activatedUntil > ?1", now);
+    }
+
+    public static long countTotalNamespaces() {
+        return count();
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

src/main/java/de/svs/metrics/CustomNamespaceActivatorMetrics.java

@@ -0,0 +1,25 @@
+package de.svs.metrics;
+
+import de.svs.Namespace;
+import io.micrometer.core.instrument.Gauge;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.quarkus.runtime.Startup;
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.inject.Inject;
+
+@Startup
+@ApplicationScoped
+public class CustomNamespaceActivatorMetrics {
+
+    @Inject
+    public CustomNamespaceActivatorMetrics(MeterRegistry registry) {
+        Gauge.builder("active_namespaces", Namespace::countActiveNamespaces)
+                .description("Number of active namespaces")
+                .register(registry);
+
+        Gauge.builder("total_namespaces", Namespace::countTotalNamespaces)
+                .description("Total number of namespaces known by the activator")
+                .register(registry);
+    }
+
+}

src/main/resources/application.properties

@@ -2,4 +2,8 @@ quarkus.mongodb.connection-string=mongodb://localhost:27017/keda
 baseDomain=.brb.dbildungscloud.dev
 quarkus.mongodb.database=keda
 namespace.deletion.cron=30 * * * * ?
-# to set a kubeconfig you have to set the kubeconfig variable, yes lowercase
+# to set a kubeconfig you have to set the kubeconfig variable, yes lowercase
+
+quarkus.management.enabled=true
+quarkus.management.port=9999
+quarkus.micrometer.export.prometheus.enabled=true