metrics-proxy: config-driven mapping as a map keyed by service (review)

Address gjoranv's review on metric-dimension-mapping.def:
- Change `mapping[].service` + `mapping[].dimension[]` to a map keyed by
  service name: `service{}.dimension[]`. Models service -> dimensions
  directly, drops the redundant service field, and makes duplicate-service
  entries impossible (the array form silently allowed duplicates).
- Use the generated Consumer<Builder> lambda overload at the three build
  sites (TestUtil.standardDimensionMapping, MetricDimensionMappingTest,
  MetricsProxyContainerCluster.getConfig) instead of building the inner
  struct explicitly.

No behaviour change: MetricDimensionMapping.allowedFor/managedDimensions and
all of ExternalMetrics/MetricsManager are unchanged; only how the config is
expressed and parsed changed.

metrics-proxy 155 green, config-model metricsproxy 23 green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: onurkaracali

config-model/src/main/java/com/yahoo/vespa/model/admin/metricsproxy/MetricsProxyContainerCluster.java

@@ -203,8 +203,7 @@ public void getConfig(MetricDimensionMappingConfig.Builder builder) {
         if (isHostedVespa()) {
             builder.defaultDimension(PublicDimensions.HOSTNAME);
             builder.defaultDimension(PublicDimensions.PARENT_HOSTNAME);
-            builder.mapping(new MetricDimensionMappingConfig.Mapping.Builder()
-                    .service(HOST_LIFE_SERVICE)
+            builder.service(HOST_LIFE_SERVICE, s -> s
                     .dimension(PublicDimensions.HOSTNAME)
                     .dimension(PublicDimensions.PARENT_HOSTNAME)
                     .dimension(PublicDimensions.OS_VERSION));

config-model/src/test/java/com/yahoo/vespa/model/admin/metricsproxy/MetricsProxyContainerClusterTest.java

@@ -118,19 +118,17 @@ void hosted_application_propagates_metric_dimension_mapping() {
 
         assertEquals(List.of(PublicDimensions.HOSTNAME, PublicDimensions.PARENT_HOSTNAME), config.defaultDimension());
 
-        assertEquals(1, config.mapping().size());
-        MetricDimensionMappingConfig.Mapping mapping = config.mapping().get(0);
-        assertEquals("host_life", mapping.service());
+        assertEquals(Set.of("host_life"), config.service().keySet());
         assertEquals(List.of(PublicDimensions.HOSTNAME, PublicDimensions.PARENT_HOSTNAME, PublicDimensions.OS_VERSION),
-                     mapping.dimension());
+                     config.service("host_life").dimension());
     }
 
     @Test
     void self_hosted_application_has_empty_metric_dimension_mapping() {
         VespaModel model = getModel(servicesWithAdminOnly(), self_hosted);
         MetricDimensionMappingConfig config = getMetricDimensionMappingConfig(model);
         assertTrue(config.defaultDimension().isEmpty());
-        assertTrue(config.mapping().isEmpty());
+        assertTrue(config.service().isEmpty());
     }
 
     @Test

metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/dimensions/MetricDimensionMapping.java

@@ -30,9 +30,9 @@ public MetricDimensionMapping(MetricDimensionMappingConfig config) {
         defaultDimensions = config.defaultDimension().stream()
                 .map(DimensionId::toDimensionId)
                 .collect(toUnmodifiableSet());
-        dimensionsByService = config.mapping().stream().collect(toUnmodifiableMap(
-                mapping -> toServiceId(mapping.service()),
-                mapping -> mapping.dimension().stream().map(DimensionId::toDimensionId).collect(toUnmodifiableSet())));
+        dimensionsByService = config.service().entrySet().stream().collect(toUnmodifiableMap(
+                entry -> toServiceId(entry.getKey()),
+                entry -> entry.getValue().dimension().stream().map(DimensionId::toDimensionId).collect(toUnmodifiableSet())));
         Set<DimensionId> all = new HashSet<>(defaultDimensions);
         dimensionsByService.values().forEach(all::addAll);
         managedDimensions = Set.copyOf(all);

metrics-proxy/src/main/resources/configdefinitions/metric-dimension-mapping.def

@@ -4,6 +4,5 @@ package=ai.vespa.metricsproxy.metric.dimensions
 # Host dimensions allowed on metrics whose service is not explicitly listed below.
 defaultDimension[] string
 
-# Per-service overrides: the host dimensions allowed on metrics from this service.
-mapping[].service string
-mapping[].dimension[] string
+# Per-service overrides, keyed by service name: the host dimensions allowed on metrics from that service.
+service{}.dimension[] string

metrics-proxy/src/test/java/ai/vespa/metricsproxy/TestUtil.java

@@ -39,8 +39,7 @@ public static MetricDimensionMapping standardDimensionMapping() {
         return new MetricDimensionMapping(new MetricDimensionMappingConfig.Builder()
                 .defaultDimension("host")
                 .defaultDimension("parentHostname")
-                .mapping(new MetricDimensionMappingConfig.Mapping.Builder()
-                        .service("host_life")
+                .service("host_life", s -> s
                         .dimension("host")
                         .dimension("parentHostname")
                         .dimension("osVersion"))

metrics-proxy/src/test/java/ai/vespa/metricsproxy/metric/dimensions/MetricDimensionMappingTest.java

@@ -20,8 +20,7 @@ public void uses_default_for_unmapped_services_and_explicit_mapping_for_listed_s
                 new MetricDimensionMappingConfig.Builder()
                         .defaultDimension("host")
                         .defaultDimension("parentHostname")
-                        .mapping(new MetricDimensionMappingConfig.Mapping.Builder()
-                                .service("host_life")
+                        .service("host_life", s -> s
                                 .dimension("host")
                                 .dimension("parentHostname")
                                 .dimension("osVersion"))