Support creating and configuring arbitrary primitive types via REST API.

core/src/main/java/io/atomix/core/Atomix.java

@@ -298,6 +298,11 @@ public Collection<PrimitiveInfo> getPrimitives(PrimitiveType primitiveType) {
     return context.primitives.getPrimitives(primitiveType);
   }
 
+  @Override
+  public <P extends DistributedPrimitive> P getPrimitive(String name) {
+    return context.primitives.getPrimitive(name);
+  }
+
   /**
    * Starts the Atomix instance.
    * <p>

core/src/main/java/io/atomix/core/PrimitivesService.java

@@ -493,6 +493,15 @@ default TransactionBuilder transactionBuilder() {
    */
   <E> WorkQueue<E> getWorkQueue(String name);
 
+  /**
+   * Returns a registered primitive.
+   *
+   * @param name the primitive name
+   * @param <P>  the primitive type
+   * @return the primitive instance
+   */
+  <P extends DistributedPrimitive> P getPrimitive(String name);
+
   /**
    * Returns a cached primitive.
    *

core/src/main/java/io/atomix/core/counter/AtomicCounterConfig.java

@@ -21,4 +21,7 @@
  * Atomic counter configuration.
  */
 public class AtomicCounterConfig extends PrimitiveConfig<AtomicCounterConfig> {
+  public AtomicCounterConfig() {
+    super(AtomicCounterType.instance());
+  }
 }

core/src/main/java/io/atomix/core/election/LeaderElectionConfig.java

@@ -21,4 +21,7 @@
  * Leader election configuration.
  */
 public class LeaderElectionConfig extends PrimitiveConfig<LeaderElectionConfig> {
+  public LeaderElectionConfig() {
+    super(LeaderElectionType.instance());
+  }
 }

core/src/main/java/io/atomix/core/election/LeaderElectorConfig.java

@@ -21,4 +21,7 @@
  * Leader elector configuration.
  */
 public class LeaderElectorConfig extends PrimitiveConfig<LeaderElectorConfig> {
+  public LeaderElectorConfig() {
+    super(LeaderElectorType.instance());
+  }
 }

core/src/main/java/io/atomix/core/generator/AtomicIdGeneratorConfig.java

@@ -21,4 +21,7 @@
  * ID generator configuration.
  */
 public class AtomicIdGeneratorConfig extends PrimitiveConfig<AtomicIdGeneratorConfig> {
+  public AtomicIdGeneratorConfig() {
+    super(AtomicIdGeneratorType.instance());
+  }
 }

core/src/main/java/io/atomix/core/impl/CorePrimitiveRegistry.java

@@ -94,6 +94,22 @@ public Collection<PrimitiveInfo> getPrimitives(PrimitiveType primitiveType) {
         .collect(Collectors.toList());
   }
 
+  @Override
+  public PrimitiveInfo getPrimitive(String name) {
+    try {
+      return primitives.get(name)
+          .thenApply(value -> value == null ? null : value.map(type -> new PrimitiveInfo(name, PrimitiveTypes.getPrimitiveType(type))).value())
+          .get(DistributedPrimitive.DEFAULT_OPERATION_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS);
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+      throw new PrimitiveException.Interrupted();
+    } catch (TimeoutException e) {
+      throw new PrimitiveException.Timeout();
+    } catch (ExecutionException e) {
+      throw new PrimitiveException(e.getCause());
+    }
+  }
+
   @Override
   public CompletableFuture<PrimitiveRegistry> start() {
     return partitionGroup.getPartitions()

core/src/main/java/io/atomix/core/impl/CorePrimitivesService.java

@@ -180,6 +180,22 @@ public <B extends DistributedPrimitiveBuilder<B, C, P>, C extends PrimitiveConfi
     return primitiveType.newPrimitiveBuilder(name, managementService);
   }
 
+  @Override
+  @SuppressWarnings("unchecked")
+  public <P extends DistributedPrimitive> P getPrimitive(String name) {
+    try {
+      return (P) cache.get(name, () -> {
+        PrimitiveInfo info = primitiveRegistry.getPrimitive(name);
+        if (info == null) {
+          return null;
+        }
+        return info.type().newPrimitiveBuilder(name, (PrimitiveConfig) config.getPrimitive(name), managementService).build();
+      });
+    } catch (ExecutionException e) {
+      throw new AtomixRuntimeException(e);
+    }
+  }
+
   @Override
   @SuppressWarnings("unchecked")
   public <C extends PrimitiveConfig<C>, P extends DistributedPrimitive> P getPrimitive(

core/src/main/java/io/atomix/core/lock/DistributedLockConfig.java

@@ -21,4 +21,7 @@
  * Distributed lock configuration.
  */
 public class DistributedLockConfig extends PrimitiveConfig<DistributedLockConfig> {
+  public DistributedLockConfig() {
+    super(DistributedLockType.instance());
+  }
 }

core/src/main/java/io/atomix/core/map/AtomicCounterMapConfig.java

@@ -21,4 +21,7 @@
  * Atomic counter map configuration.
  */
 public class AtomicCounterMapConfig extends PrimitiveConfig<AtomicCounterMapConfig> {
+  public AtomicCounterMapConfig() {
+    super(AtomicCounterMapType.instance());
+  }
 }

core/src/main/java/io/atomix/core/map/ConsistentMapConfig.java

@@ -23,6 +23,10 @@
 public class ConsistentMapConfig extends PrimitiveConfig<ConsistentMapConfig> {
   private boolean nullValues = false;
 
+  public ConsistentMapConfig() {
+    super(ConsistentMapType.instance());
+  }
+
   /**
    * Enables null values in the map.
    *

core/src/main/java/io/atomix/core/map/ConsistentTreeMapConfig.java

@@ -21,4 +21,7 @@
  * Consistent tree-map configuration.
  */
 public class ConsistentTreeMapConfig extends PrimitiveConfig<ConsistentTreeMapConfig> {
+  public ConsistentTreeMapConfig() {
+    super(ConsistentTreeMapType.instance());
+  }
 }

core/src/main/java/io/atomix/core/multimap/ConsistentMultimapConfig.java

@@ -21,4 +21,7 @@
  * Consistent multimap configuration.
  */
 public class ConsistentMultimapConfig extends PrimitiveConfig<ConsistentMultimapConfig> {
+  public ConsistentMultimapConfig() {
+    super(ConsistentMultimapType.instance());
+  }
 }

core/src/main/java/io/atomix/core/queue/WorkQueueConfig.java

@@ -21,4 +21,7 @@
  * Work queue configuration.
  */
 public class WorkQueueConfig extends PrimitiveConfig<WorkQueueConfig> {
+  public WorkQueueConfig() {
+    super(WorkQueueType.instance());
+  }
 }

core/src/main/java/io/atomix/core/set/DistributedSetConfig.java

@@ -21,4 +21,7 @@
  * Distributed set configuration.
  */
 public class DistributedSetConfig extends PrimitiveConfig<DistributedSetConfig> {
+  public DistributedSetConfig() {
+    super(DistributedSetType.instance());
+  }
 }

core/src/main/java/io/atomix/core/transaction/TransactionConfig.java

@@ -25,6 +25,10 @@
 public class TransactionConfig extends PrimitiveConfig<TransactionConfig> {
   private Isolation isolation = Isolation.READ_COMMITTED;
 
+  public TransactionConfig() {
+    super(TransactionType.instance());
+  }
+
   /**
    * Sets the transaction isolation level.
    *

core/src/main/java/io/atomix/core/transaction/TransactionalMapConfig.java

@@ -15,10 +15,14 @@
  */
 package io.atomix.core.transaction;
 
+import io.atomix.core.map.ConsistentMapType;
 import io.atomix.primitive.PrimitiveConfig;
 
 /**
  * Transactional map configuration.
  */
 public class TransactionalMapConfig extends PrimitiveConfig {
+  public TransactionalMapConfig() {
+    super(ConsistentMapType.instance());
+  }
 }

core/src/main/java/io/atomix/core/transaction/TransactionalSetConfig.java

@@ -15,10 +15,14 @@
  */
 package io.atomix.core.transaction;
 
+import io.atomix.core.set.DistributedSetType;
 import io.atomix.primitive.PrimitiveConfig;
 
 /**
  * Transactional set configuration.
  */
 public class TransactionalSetConfig extends PrimitiveConfig {
+  public TransactionalSetConfig() {
+    super(DistributedSetType.instance());
+  }
 }

core/src/main/java/io/atomix/core/tree/DocumentTreeConfig.java

@@ -24,6 +24,10 @@
 public class DocumentTreeConfig extends PrimitiveConfig<DocumentTreeConfig> {
   private Ordering ordering;
 
+  public DocumentTreeConfig() {
+    super(DocumentTreeType.instance());
+  }
+
   /**
    * Sets the ordering of the tree nodes.
    * <p>

core/src/main/java/io/atomix/core/value/AtomicValueConfig.java

@@ -21,4 +21,7 @@
  * Atomic value configuration.
  */
 public class AtomicValueConfig extends PrimitiveConfig<AtomicValueConfig> {
+  public AtomicValueConfig() {
+    super(AtomicValueType.instance());
+  }
 }

primitive/src/main/java/io/atomix/primitive/PrimitiveConfig.java

@@ -23,12 +23,26 @@
 public abstract class PrimitiveConfig<C extends PrimitiveConfig<C>> {
   private static final int DEFAULT_CACHE_SIZE = 1000;
 
+  private final PrimitiveType primitiveType;
   private SerializerConfig serializerConfig;
   private PrimitiveProtocolConfig protocolConfig;
   private boolean cacheEnabled = false;
   private int cacheSize = DEFAULT_CACHE_SIZE;
   private boolean readOnly = false;
 
+  protected PrimitiveConfig(PrimitiveType primitiveType) {
+    this.primitiveType = primitiveType;
+  }
+
+  /**
+   * Returns the primitive type.
+   *
+   * @return the primitive type
+   */
+  public PrimitiveType getType() {
+    return primitiveType;
+  }
+
   /**
    * Returns the serializer configuration.
    *

primitive/src/main/java/io/atomix/primitive/PrimitiveRegistry.java

@@ -47,4 +47,12 @@ public interface PrimitiveRegistry {
    */
   Collection<PrimitiveInfo> getPrimitives(PrimitiveType primitiveType);
 
+  /**
+   * Returns the info for a single primitive.
+   *
+   * @param name the primitive name
+   * @return the primitive info
+   */
+  PrimitiveInfo getPrimitive(String name);
+
 }

primitive/src/main/java/io/atomix/primitive/PrimitiveType.java

@@ -20,6 +20,7 @@
 import io.atomix.utils.Generics;
 import io.atomix.utils.Identifier;
 
+import java.util.function.Function;
 import java.util.function.Supplier;
 
 /**
@@ -77,7 +78,7 @@ default Class<? extends DistributedPrimitive> primitiveClass() {
    *
    * @return the primitive resource factory
    */
-  default Supplier<PrimitiveResource> resourceFactory() {
+  default Function<P, PrimitiveResource> resourceFactory() {
     return null;
   }