fix(metrics): support new micrometer prometheus package and make pushgateway optional

dubbo-metrics/dubbo-metrics-api/src/main/java/org/apache/dubbo/metrics/utils/MetricsSupportUtil.java

@@ -25,10 +25,16 @@ public static boolean isSupportMetrics() {
     }
 
     public static boolean isSupportPrometheus() {
-        return isClassPresent("io.micrometer.prometheus.PrometheusConfig")
-                && isClassPresent("io.prometheus.client.exporter.BasicAuthHttpConnectionFactory")
-                && isClassPresent("io.prometheus.client.exporter.HttpConnectionFactory")
-                && isClassPresent("io.prometheus.client.exporter.PushGateway");
+        // Micrometer 1.13+ renamed the prometheus package:
+        // io.micrometer.prometheus.* -> io.micrometer.prometheusmetrics.*
+        // Accept either package to support both old and new versions.
+        boolean hasPrometheusConfig = isClassPresent("io.micrometer.prometheus.PrometheusConfig")
+                || isClassPresent("io.micrometer.prometheusmetrics.PrometheusConfig");
+
+        // PushGateway classes (io.prometheus.client.exporter.*) are only needed
+        // when pushgateway mode is enabled, not for the default scrape endpoint.
+        // Do not require them here to avoid blocking reporter initialization.
+        return hasPrometheusConfig;
     }
 
     private static boolean isClassPresent(String className) {

dubbo-metrics/dubbo-metrics-api/src/test/java/org/apache/dubbo/metrics/utils/MetricsSupportUtilTest.java

@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.metrics.utils;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class MetricsSupportUtilTest {
+
+    @Test
+    void isSupportMetricsShouldReturnTrue() {
+        // micrometer-core is on the test classpath
+        Assertions.assertTrue(MetricsSupportUtil.isSupportMetrics());
+    }
+
+    @Test
+    void isSupportPrometheusShouldNotThrow() {
+        // Prometheus support depends on classpath; verify no exception is thrown
+        // regardless of which micrometer-prometheus variant is available.
+        boolean result = MetricsSupportUtil.isSupportPrometheus();
+        // In the dubbo-metrics-api test context, prometheus classes are not present
+        Assertions.assertFalse(result);
+    }
+}

dubbo-metrics/dubbo-metrics-prometheus/src/main/java/org/apache/dubbo/metrics/prometheus/PrometheusMetricsReporter.java

@@ -71,22 +71,33 @@ public String getResponse() {
     private void schedulePushJob() {
         boolean pushEnabled = url.getParameter(PROMETHEUS_PUSHGATEWAY_ENABLED_KEY, false);
         if (pushEnabled) {
-            String baseUrl = url.getParameter(PROMETHEUS_PUSHGATEWAY_BASE_URL_KEY);
-            String job = url.getParameter(PROMETHEUS_PUSHGATEWAY_JOB_KEY, PROMETHEUS_DEFAULT_JOB_NAME);
-            int pushInterval =
-                    url.getParameter(PROMETHEUS_PUSHGATEWAY_PUSH_INTERVAL_KEY, PROMETHEUS_DEFAULT_PUSH_INTERVAL);
-            String username = url.getParameter(PROMETHEUS_PUSHGATEWAY_USERNAME_KEY);
-            String password = url.getParameter(PROMETHEUS_PUSHGATEWAY_PASSWORD_KEY);
-
-            NamedThreadFactory threadFactory = new NamedThreadFactory("prometheus-push-job", true);
-            pushJobExecutor = Executors.newScheduledThreadPool(1, threadFactory);
-            PushGateway pushGateway = new PushGateway(baseUrl);
-            if (!StringUtils.isBlank(username)) {
-                pushGateway.setConnectionFactory(new BasicAuthHttpConnectionFactory(username, password));
+            try {
+                String baseUrl = url.getParameter(PROMETHEUS_PUSHGATEWAY_BASE_URL_KEY);
+                String job = url.getParameter(PROMETHEUS_PUSHGATEWAY_JOB_KEY, PROMETHEUS_DEFAULT_JOB_NAME);
+                int pushInterval =
+                        url.getParameter(PROMETHEUS_PUSHGATEWAY_PUSH_INTERVAL_KEY, PROMETHEUS_DEFAULT_PUSH_INTERVAL);
+                String username = url.getParameter(PROMETHEUS_PUSHGATEWAY_USERNAME_KEY);
+                String password = url.getParameter(PROMETHEUS_PUSHGATEWAY_PASSWORD_KEY);
+
+                NamedThreadFactory threadFactory = new NamedThreadFactory("prometheus-push-job", true);
+                pushJobExecutor = Executors.newScheduledThreadPool(1, threadFactory);
+                PushGateway pushGateway = new PushGateway(baseUrl);
+                if (!StringUtils.isBlank(username)) {
+                    pushGateway.setConnectionFactory(new BasicAuthHttpConnectionFactory(username, password));
+                }
+
+                pushJobExecutor.scheduleWithFixedDelay(
+                        () -> push(pushGateway, job), pushInterval, pushInterval, TimeUnit.SECONDS);
+            } catch (NoClassDefFoundError e) {
+                logger.warn(
+                        COMMON_METRICS_COLLECTOR_EXCEPTION,
+                        "",
+                        "",
+                        "PushGateway classes not found on classpath. "
+                                + "Add simpleclient_pushgateway dependency to use pushgateway mode. "
+                                + "Scrape endpoint will still work.",
+                        e);
             }
-
-            pushJobExecutor.scheduleWithFixedDelay(
-                    () -> push(pushGateway, job), pushInterval, pushInterval, TimeUnit.SECONDS);
         }
     }
 

dubbo-metrics/dubbo-metrics-prometheus/src/main/java/org/apache/dubbo/metrics/prometheus/PrometheusMetricsReporterFactory.java

@@ -74,9 +74,14 @@ private static boolean dependenciesNotFound(String msg) {
         if (msg == null) {
             return false;
         }
-        if (msg.contains("io/micrometer/core/instrument/composite/CompositeMeterRegistry")) {
+        // Micrometer core classes
+        if (msg.contains("io/micrometer/") || msg.contains("io.micrometer.")) {
             return true;
         }
-        return msg.contains("io.micrometer.core.instrument.composite.CompositeMeterRegistry");
+        // Prometheus client classes (old simpleclient or new client)
+        if (msg.contains("io/prometheus/") || msg.contains("io.prometheus.")) {
+            return true;
+        }
+        return false;
     }
 }