apache#3318 Fix config query

common/src/main/java/io/druid/guice/JsonConfigProvider.java

@@ -164,7 +164,7 @@ public static <T> void bind(
       Key<Supplier<T>> supplierKey
   )
   {
-    binder.bind(supplierKey).toProvider((Provider) of(propertyBase, clazz, defaultValue)).in(LazySingleton.class);
+    binder.bind(supplierKey).toProvider(of(propertyBase, clazz, defaultValue)).in(LazySingleton.class);
     binder.bind(instanceKey).toProvider(new SupplierProvider<T>(supplierKey));
     BASE_TO_CLASS.put(propertyBase, supplierKey);
   }
@@ -252,7 +252,8 @@ public static <T> JsonConfigProvider<T> of(String propertyBase, Class<T> classTo
   private Properties props;
   private JsonConfigurator configurator;
 
-  private Supplier<T> retVal = null;
+  private Map<String, String> overrides = Maps.newHashMap();
+  private Supplier<T> retVal;
 
   public JsonConfigProvider(
       String propertyBase,
@@ -283,7 +284,7 @@ public Supplier<T> get()
     }
 
     try {
-      final T config = configurator.configurate(props, propertyBase, classToProvide, defaultValue, null);
+      final T config = configurator.configurate(props, propertyBase, classToProvide, defaultValue, overrides);
       retVal = Suppliers.ofInstance(config);
     }
     catch (RuntimeException e) {
@@ -299,9 +300,11 @@ public Supplier<T> get()
 
   private void configure(Map<String, String> properties)
   {
-    Supplier<T> supplier = get();
+    Map<String, String> overriding = Maps.newHashMap(overrides);
+    overriding.putAll(properties);
     retVal = Suppliers.ofInstance(
-        configurator.configurate(props, propertyBase, classToProvide, supplier.get(), properties)
+        configurator.configurate(props, propertyBase, classToProvide, defaultValue, overriding)
     );
+    overrides = overriding;
   }
 }

common/src/main/java/io/druid/guice/JsonConfigurator.java

@@ -35,6 +35,7 @@
 import com.google.inject.Inject;
 import com.google.inject.ProvisionException;
 import com.google.inject.spi.Message;
+import io.druid.common.guava.GuavaUtils;
 import io.druid.java.util.common.logger.Logger;
 
 import javax.validation.ConstraintViolation;
@@ -129,7 +130,7 @@ public <T> T configurate(
         values.put(prop.substring(propertyBase.length()), value);
       }
     }
-    if (override != null) {
+    if (!GuavaUtils.isNullOrEmpty(override)) {
       values.putAll(override);
     }
 

server/src/main/java/io/druid/query/config/ConfigQuery.java

@@ -22,6 +22,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Ordering;
 import io.druid.client.DruidServer;
 import io.druid.query.BaseQuery;
 import io.druid.query.DataSource;
@@ -114,6 +115,12 @@ public Map<String, Map<String, String>> getConfig()
     return config;
   }
 
+  @Override
+  public Ordering<Map<String, Object>> getMergeOrdering()
+  {
+    return null;
+  }
+
   @Override
   public List<DruidServer> filter(List<DruidServer> servers)
   {

server/src/main/java/io/druid/server/http/AdminResource.java

@@ -22,11 +22,14 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectWriter;
+import com.google.common.base.Supplier;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Maps;
+import com.google.inject.Injector;
 import io.druid.common.guava.GuavaUtils;
 import io.druid.common.utils.StringUtils;
 import io.druid.common.utils.VMUtils;
+import io.druid.guice.JsonConfigProvider;
 import io.druid.guice.annotations.Json;
 import io.druid.guice.annotations.Self;
 import io.druid.java.util.common.IAE;
@@ -78,17 +81,20 @@ public class AdminResource
   private final DruidNode node;
   private final Shutdown.Proc shutdown;
   private final ObjectMapper objectMapper;
+  private final Injector injector;
 
   @Inject
   public AdminResource(
       @Self DruidNode node,
       @Shutdown Shutdown.Proc shutdown,
-      @Json ObjectMapper objectMapper
+      @Json ObjectMapper objectMapper,
+      Injector injector
   )
   {
     this.node = node;
     this.shutdown = shutdown;
     this.objectMapper = objectMapper;
+    this.injector = injector;
   }
 
   @GET
@@ -116,6 +122,16 @@ public Response jmx(@QueryParam("pretty") String pretty)
     return Response.ok(result).build();
   }
 
+  @GET
+  @Path("/config/{configKey}")
+  @Produces(MediaType.TEXT_PLAIN)
+  public Response getConfig(@PathParam("configKey") String configKey) throws JsonProcessingException
+  {
+    final Object value = JsonConfigProvider.get(injector, configKey);
+    final Object entity = value instanceof Supplier ? ((Supplier) value).get() : value;
+    return Response.ok(objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(entity)).build();
+  }
+
   @GET
   @Path("/stack")
   @Produces(MediaType.TEXT_PLAIN)
@@ -173,6 +189,16 @@ public Response setLogLevel(@PathParam("name") String name, @PathParam("level")
     return handleLogLevel(name, level);
   }
 
+  private Response handleLogLevel(String name, Level level)
+  {
+    LoggerContext context = (LoggerContext) LogManager.getContext(false);
+    Logger logger = "root".equalsIgnoreCase(name) ? context.getRootLogger() : context.getLogger(name);
+    if (level != null) {
+      logger.setLevel(level);
+    }
+    return Response.ok(String.format("%s --> %s", name, logger.getLevel())).build();
+  }
+
   @GET
   @Path("/jcmd/help")
   @Produces(MediaType.APPLICATION_JSON)
@@ -210,16 +236,6 @@ public Response jcmd(
     return Response.ok(VMUtils.jcmd(command, params)).build();
   }
 
-  private Response handleLogLevel(String name, Level level)
-  {
-    LoggerContext context = (LoggerContext) LogManager.getContext(false);
-    Logger logger = "root".equalsIgnoreCase(name) ? context.getRootLogger() : context.getLogger(name);
-    if (level != null) {
-      logger.setLevel(level);
-    }
-    return Response.ok(String.format("%s --> %s", name, logger.getLevel())).build();
-  }
-
   private static final int DEFAULT_LOG_QUEUE_SIZE = 1024;
   private static final int DEFAULT_LOG_POLLING_SEC = 300;   // 5 min