Added production readiness check

Author: fivetran-kostaszoumpatianos

runtime/service/src/main/java/org/apache/polaris/service/config/ProductionReadinessChecks.java

@@ -44,6 +44,7 @@
 import org.apache.polaris.service.context.TestRealmContextResolver;
 import org.apache.polaris.service.events.PolarisEventListener;
 import org.apache.polaris.service.events.TestPolarisEventListener;
+import org.apache.polaris.service.metrics.MetricsConfiguration;
 import org.apache.polaris.service.persistence.InMemoryPolarisMetaStoreManagerFactory;
 import org.eclipse.microprofile.config.Config;
 import org.eclipse.microprofile.config.ConfigValue;
@@ -113,6 +114,17 @@ public void warnOnFailedChecks(
     }
   }
 
+  @Produces
+  public ProductionReadinessCheck checkMetricTags(MetricsConfiguration config) {
+    if (config.userPrincipalTag().enableInApiMetrics()) {
+      return ProductionReadinessCheck.of(
+          Error.of(
+              "Metrics configuration includes user principal name in tags.",
+              "polaris.metrics.user-principal-tag.enable-in-api-metrics"));
+    }
+    return ProductionReadinessCheck.OK;
+  }
+
   @Produces
   public ProductionReadinessCheck checkTokenBrokers(AuthenticationConfiguration configuration) {
     List<ProductionReadinessCheck.Error> errors = new ArrayList<>();