[Backport] Add labels to sys.server

docs/configuration/index.md

@@ -741,6 +741,7 @@ These Coordinator static configurations can be defined in the `coordinator/runti
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`|8081|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative integer.|8281|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services.|`druid/coordinator`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 ##### Coordinator operation
 
@@ -984,6 +985,7 @@ These Overlord static configurations can be defined in the `overlord/runtime.pro
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`.|8090|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative Integer.|8290|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services.|`druid/overlord`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 ##### Overlord operations
 
@@ -1335,6 +1337,7 @@ These Middle Manager and Peon configurations can be defined in the `middleManage
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`|8091|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative Integer.|8291|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services|`druid/middlemanager`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 #### Middle Manager configuration
 
@@ -1463,6 +1466,7 @@ For most types of tasks, `SegmentWriteOutMediumFactory` can be configured per-ta
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`|8091|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative Integer.|8283|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services|`druid/indexer`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 #### Indexer general configuration
 
@@ -1558,6 +1562,7 @@ These Historical configurations can be defined in the `historical/runtime.proper
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`|8083|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative Integer.|8283|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services|`druid/historical`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 #### Historical general configuration
 
@@ -1671,6 +1676,7 @@ These Broker configurations can be defined in the `broker/runtime.properties` fi
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`|8082|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative Integer.|8282|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services|`druid/broker`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 #### Query configuration
 
@@ -2290,6 +2296,7 @@ Supported query contexts:
 |`druid.plaintextPort`|This is the port to actually listen on; unless port mapping is used, this will be the same port as is on `druid.host`|8888|
 |`druid.tlsPort`|TLS port for HTTPS connector, if [druid.enableTlsPort](../operations/tls-support.md) is set then this config will be used. If `druid.host` contains port then that port will be ignored. This should be a non-negative Integer.|9088|
 |`druid.service`|The name of the service. This is used as a dimension when emitting metrics and alerts to differentiate between the various services|`druid/router`|
+|`druid.labels`|Optional JSON object of key-value pairs that define custom labels for the server. These labels are displayed in the web console under the "Services" tab. Example: `druid.labels={"location":"Airtrunk"}` or `druid.labels.location=Airtrunk`|`null`|
 
 #### Runtime configuration
 

docs/querying/sql-metadata-tables.md

@@ -237,6 +237,7 @@ Servers table lists all discovered servers in the cluster.
 |is_leader|BIGINT|1 if the server is currently the 'leader' (for services which have the concept of leadership), otherwise 0 if the server is not the leader, or null if the server type does not have the concept of leadership|
 |start_time|STRING|Timestamp in ISO8601 format when the server was announced in the cluster|
 |version|VARCHAR|Druid version running on the server|
+|labels|VARCHAR|Labels for the server configured using the property [`druid.labels`](../configuration/index.md)|
 To retrieve information about all servers, use the query:
 
 ```sql

integration-tests-ex/cases/src/test/java/org/apache/druid/testsEx/config/Initializer.java

@@ -148,7 +148,7 @@ public void configure(Binder binder)
           .in(LazySingleton.class);
 
       // Dummy DruidNode instance to make Guice happy. This instance is unused.
-      DruidNode dummy = new DruidNode("integration-tests", "localhost", false, 9191, null, null, true, false);
+      DruidNode dummy = new DruidNode("integration-tests", "localhost", false, 9191, null, null, true, false, null);
       binder
           .bind(DruidNode.class)
           .annotatedWith(Self.class)

integration-tests/src/main/java/org/apache/druid/testing/guice/DruidTestModule.java

@@ -56,7 +56,7 @@ public void configure(Binder binder)
 
     // Bind DruidNode instance to make Guice happy. This instance is currently unused.
     binder.bind(DruidNode.class).annotatedWith(Self.class).toInstance(
-        new DruidNode("integration-tests", "localhost", false, 9191, null, null, true, false)
+        new DruidNode("integration-tests", "localhost", false, 9191, null, null, true, false, null)
     );
 
     // Required for MSQIndexingModule

integration-tests/src/test/resources/results/auth_test_sys_schema_servers.json

@@ -10,7 +10,8 @@
     "max_size": 5000000000,
     "is_leader": null,
     "start_time": "0",
-    "version": "0.0.0"
+    "version": "0.0.0",
+    "labels": null
   },
   {
     "server": "%%BROKER%%:8282",
@@ -23,6 +24,7 @@
     "max_size": 1000000000,
     "is_leader": null,
     "start_time": "0",
-    "version": "0.0.0"
+    "version": "0.0.0",
+    "labels": null
   }
 ]

processing/src/main/java/org/apache/druid/java/util/common/jackson/JacksonUtils.java

@@ -30,6 +30,8 @@
 import com.fasterxml.jackson.databind.JsonSerializer;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializerProvider;
+import org.apache.druid.error.DruidException;
+import org.apache.druid.error.InternalServerError;
 import org.apache.druid.java.util.common.ISE;
 
 import javax.annotation.Nullable;
@@ -119,6 +121,16 @@ public static void writeObjectUsingSerializerProvider(
     }
   }
 
+  public static String writeValueAsString(ObjectMapper jsonMapper, Object value) throws DruidException
+  {
+    try {
+      return jsonMapper.writeValueAsString(value);
+    }
+    catch (JsonProcessingException e) {
+      throw InternalServerError.exception(e, "Failed to serialize object as JSON");
+    }
+  }
+
   /**
    * Reads an object using the {@link JsonParser}. It reuses the provided {@link DeserializationContext} which offers
    * better performance that calling {@link JsonParser#readValueAs(Class)} because it avoids re-creating the {@link DeserializationContext}

server/src/main/java/org/apache/druid/server/DruidNode.java

@@ -30,13 +30,14 @@
 import org.apache.druid.java.util.common.IAE;
 import org.apache.druid.java.util.common.ISE;
 
+import javax.annotation.Nullable;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.NotNull;
-
 import java.net.InetAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.UnknownHostException;
+import java.util.Map;
 import java.util.Objects;
 
 /**
@@ -91,6 +92,9 @@ public class DruidNode
       UNKNOWN_VERSION
   );
 
+  @JsonProperty
+  private Map<String, String> labels;
+
   public DruidNode(
       String serviceName,
       String host,
@@ -101,7 +105,7 @@ public DruidNode(
       boolean enableTlsPort
   )
   {
-    this(serviceName, host, bindOnHost, plaintextPort, null, tlsPort, enablePlaintextPort, enableTlsPort);
+    this(serviceName, host, bindOnHost, plaintextPort, null, tlsPort, enablePlaintextPort, enableTlsPort, null);
   }
 
   /**
@@ -129,7 +133,8 @@ public DruidNode(
       @JacksonInject @Named("servicePort") @JsonProperty("port") Integer port,
       @JacksonInject @Named("tlsServicePort") @JsonProperty("tlsPort") Integer tlsPort,
       @JsonProperty("enablePlaintextPort") Boolean enablePlaintextPort,
-      @JsonProperty("enableTlsPort") boolean enableTlsPort
+      @JsonProperty("enableTlsPort") boolean enableTlsPort,
+      @JsonProperty("labels") @Nullable Map<String, String> labels
   )
   {
     init(
@@ -138,8 +143,9 @@ public DruidNode(
         bindOnHost,
         plaintextPort != null ? plaintextPort : port,
         tlsPort,
-        enablePlaintextPort == null ? true : enablePlaintextPort.booleanValue(),
-        enableTlsPort
+        enablePlaintextPort == null || enablePlaintextPort.booleanValue(),
+        enableTlsPort,
+        labels
     );
   }
 
@@ -150,7 +156,8 @@ private void init(
       Integer plainTextPort,
       Integer tlsPort,
       boolean enablePlaintextPort,
-      boolean enableTlsPort
+      boolean enableTlsPort,
+      Map<String, String> labels
   )
   {
     Preconditions.checkNotNull(serviceName);
@@ -210,6 +217,13 @@ private void init(
     this.serviceName = serviceName;
     this.host = host;
     this.bindOnHost = bindOnHost;
+    this.labels = labels;
+  }
+
+  @Nullable
+  public Map<String, String> getLabels()
+  {
+    return labels;
   }
 
   public String getServiceName()
@@ -336,13 +350,14 @@ public boolean equals(Object o)
            tlsPort == druidNode.tlsPort &&
            enableTlsPort == druidNode.enableTlsPort &&
            Objects.equals(serviceName, druidNode.serviceName) &&
-           Objects.equals(host, druidNode.host);
+           Objects.equals(host, druidNode.host) &&
+           Objects.equals(labels, druidNode.labels);
   }
 
   @Override
   public int hashCode()
   {
-    return Objects.hash(serviceName, host, port, plaintextPort, enablePlaintextPort, tlsPort, enableTlsPort);
+    return Objects.hash(serviceName, host, port, plaintextPort, enablePlaintextPort, tlsPort, enableTlsPort, labels);
   }
 
   @Override
@@ -357,6 +372,7 @@ public String toString()
            ", enablePlaintextPort=" + enablePlaintextPort +
            ", tlsPort=" + tlsPort +
            ", enableTlsPort=" + enableTlsPort +
+           ", labels=" + labels +
            '}';
   }
 }

server/src/test/java/org/apache/druid/discovery/DiscoveryDruidNodeTest.java

@@ -112,7 +112,8 @@ public void testSerdeWithDataNodeAndLookupNodeServices() throws JsonProcessingEx
             -1,
             8282,
             true,
-            true
+            true,
+            null
         ),
         NodeRole.BROKER,
         ImmutableMap.of(
@@ -167,7 +168,8 @@ public void testDeserializeWithDataNodeServiceWithAWrongPropertyOrder() throws J
                 -1,
                 8282,
                 true,
-                true
+                true,
+                null
             ),
             NodeRole.BROKER,
             ImmutableMap.of(
@@ -216,7 +218,8 @@ public void testDeserialize_duplicateProperties_shouldSucceedToDeserialize() thr
                 -1,
                 8282,
                 true,
-                true
+                true,
+                null
             ),
             NodeRole.BROKER,
             ImmutableMap.of(
@@ -266,7 +269,8 @@ public void testDeserialize_duplicateKeysWithDifferentValus_shouldIgnoreDataNode
                 -1,
                 8282,
                 true,
-                true
+                true,
+                null
             ),
             NodeRole.BROKER,
             ImmutableMap.of()