Make HTTP templates for observability work with subresources

extensions/resteasy-reactive/quarkus-resteasy-reactive/runtime/src/main/java/io/quarkus/resteasy/reactive/server/runtime/observability/ObservabilityCustomizer.java

@@ -13,9 +13,17 @@ public class ObservabilityCustomizer implements HandlerChainCustomizer {
     public List<ServerRestHandler> handlers(Phase phase, ResourceClass resourceClass,
             ServerResourceMethod serverResourceMethod) {
         if (phase.equals(Phase.AFTER_MATCH)) {
+            String basePath = resourceClass.getPath();
+            boolean isSubResource = basePath == null;
             ObservabilityHandler observabilityHandler = new ObservabilityHandler();
-            observabilityHandler
-                    .setTemplatePath(resourceClass.getPath() + serverResourceMethod.getPath());
+            if (isSubResource) {
+                observabilityHandler.setTemplatePath(serverResourceMethod.getPath());
+                observabilityHandler.setSubResource(true);
+            } else {
+                observabilityHandler.setTemplatePath(basePath + serverResourceMethod.getPath());
+                observabilityHandler.setSubResource(false);
+            }
+
             return Collections.singletonList(observabilityHandler);
         }
         return Collections.emptyList();

extensions/resteasy-reactive/quarkus-resteasy-reactive/runtime/src/main/java/io/quarkus/resteasy/reactive/server/runtime/observability/ObservabilityHandler.java

@@ -16,6 +16,8 @@ public class ObservabilityHandler implements ServerRestHandler {
     // make mutable to allow for bytecode serialization
     private String templatePath;
 
+    private boolean isSubResource;
+
     public String getTemplatePath() {
         return templatePath;
     }
@@ -24,9 +26,26 @@ public void setTemplatePath(String templatePath) {
         this.templatePath = MULTIPLE_SLASH_PATTERN.matcher(templatePath).replaceAll("/");
     }
 
+    public boolean isSubResource() {
+        return isSubResource;
+    }
+
+    public void setSubResource(boolean subResource) {
+        isSubResource = subResource;
+    }
+
     @Override
     public void handle(ResteasyReactiveRequestContext requestContext) throws Exception {
-        setUrlPathTemplate(requestContext.unwrap(RoutingContext.class), templatePath);
+        RoutingContext routingContext = requestContext.unwrap(RoutingContext.class);
+        if (isSubResource) {
+            var previous = getUrlPathTemplate(routingContext);
+            if (previous == null) {
+                previous = "";
+            }
+            setUrlPathTemplate(routingContext, previous + templatePath);
+        } else {
+            setUrlPathTemplate(routingContext, templatePath);
+        }
     }
 
 }

extensions/resteasy-reactive/quarkus-resteasy-reactive/runtime/src/main/java/io/quarkus/resteasy/reactive/server/runtime/observability/ObservabilityUtil.java

@@ -1,5 +1,6 @@
 package io.quarkus.resteasy.reactive.server.runtime.observability;
 
+import io.vertx.core.Context;
 import io.vertx.core.http.impl.HttpServerRequestInternal;
 import io.vertx.ext.web.RoutingContext;
 
@@ -9,7 +10,14 @@ private ObservabilityUtil() {
     }
 
     static void setUrlPathTemplate(RoutingContext routingContext, String templatePath) {
-        ((HttpServerRequestInternal) (routingContext.request())).context()
-                .putLocal("UrlPathTemplate", templatePath);
+        getRequestContext(routingContext).putLocal("UrlPathTemplate", templatePath);
+    }
+
+    static String getUrlPathTemplate(RoutingContext routingContext) {
+        return getRequestContext(routingContext).getLocal("UrlPathTemplate");
+    }
+
+    private static Context getRequestContext(RoutingContext routingContext) {
+        return ((HttpServerRequestInternal) (routingContext.request())).context();
     }
 }

integration-tests/micrometer-prometheus/src/main/java/io/quarkus/it/micrometer/prometheus/RootResource.java

@@ -0,0 +1,13 @@
+package io.quarkus.it.micrometer.prometheus;
+
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+
+@Path("/root")
+public class RootResource {
+
+    @Path("{rootParam}/sub")
+    public SubResource subResource(@PathParam("rootParam") String value) {
+        return new SubResource(value);
+    }
+}

integration-tests/micrometer-prometheus/src/main/java/io/quarkus/it/micrometer/prometheus/SubResource.java

@@ -0,0 +1,20 @@
+package io.quarkus.it.micrometer.prometheus;
+
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+
+public class SubResource {
+
+    private final String value;
+
+    public SubResource(String value) {
+        this.value = value;
+    }
+
+    @GET
+    @Path("/{subParam}")
+    public String get(@PathParam("subParam") String subParam) {
+        return value + ":" + subParam;
+    }
+}

integration-tests/micrometer-prometheus/src/test/java/io/quarkus/it/micrometer/prometheus/PrometheusMetricsRegistryTest.java

@@ -98,6 +98,13 @@ void testSecuredEndpoint() {
 
     @Test
     @Order(11)
+    void testTemplatedPathOnSubResource() {
+        when().get("/root/r1/sub/s2").then().statusCode(200)
+                .body(containsString("r1:s2"));
+    }
+
+    @Test
+    @Order(20)
     void testPrometheusScrapeEndpointTextPlain() {
         RestAssured.given().header("Accept", TextFormat.CONTENT_TYPE_004)
                 .when().get("/q/metrics")
@@ -133,6 +140,9 @@ void testPrometheusScrapeEndpointTextPlain() {
                 .body(containsString(
                         "http_server_requests_seconds_count{dummy=\"value\",env=\"test\",env2=\"test\",foo=\"UNSET\",method=\"GET\",outcome=\"SUCCESS\",registry=\"prometheus\",status=\"200\",uri=\"/template/path/{value}\""))
 
+                .body(containsString(
+                        "http_server_requests_seconds_count{dummy=\"value\",env=\"test\",env2=\"test\",foo=\"UNSET\",method=\"GET\",outcome=\"SUCCESS\",registry=\"prometheus\",status=\"200\",uri=\"/root/{rootParam}/sub/{subParam}\""))
+
                 // Verify Hibernate Metrics
                 .body(containsString(
                         "hibernate_sessions_open_total{entityManagerFactory=\"<default>\",env=\"test\",env2=\"test\",registry=\"prometheus\",} 2.0"))
@@ -195,7 +205,7 @@ void testPrometheusScrapeEndpointTextPlain() {
     }
 
     @Test
-    @Order(11)
+    @Order(20)
     void testPrometheusScrapeEndpointOpenMetrics() {
         RestAssured.given().header("Accept", TextFormat.CONTENT_TYPE_OPENMETRICS_100)
                 .when().get("/q/metrics")