Implementing net config subsystem and revising its interfaces.

Added a few basic configs for device, host and links.

Added initial REST API.

Added CLI.

Tests remain to be added.

Change-Id: Ic7bba4b5ad7d553c51d69f6459b3bff146970323
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/Config.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/Config.java
index dacef68..12f3114 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/config/Config.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/Config.java
@@ -23,41 +23,67 @@
 
 /**
  * Base abstraction of a configuration facade for a specific subject. Derived
- * classes should keep all state in the specified JSON tree.
+ * classes should keep all state in the specified JSON tree as that is the
+ * only state that will be distributed or persisted; this class is merely
+ * a facade for interacting with a particular facet of configuration on a
+ * given subject.
  *
  * @param <S> type of subject
  */
 @Beta
 public abstract class Config<S> {
 
-    protected ObjectMapper mapper;
+    protected S subject;
+    protected String key;
     protected ObjectNode node;
-    private S subject;
-    private ConfigApplyDelegate<S> delegate;
+    protected ObjectMapper mapper;
+    protected ConfigApplyDelegate delegate;
+
+    /**
+     * Initializes the configuration behaviour with necessary context.
+     *
+     * @param subject  configuration subject
+     * @param key      configuration key
+     * @param node     JSON object node where configuration data is stored
+     * @param mapper   JSON object mapper
+     * @param delegate delegate context
+     */
+    public void init(S subject, String key, ObjectNode node, ObjectMapper mapper,
+                     ConfigApplyDelegate delegate) {
+        this.subject = checkNotNull(subject);
+        this.key = key;
+        this.node = checkNotNull(node);
+        this.mapper = checkNotNull(mapper);
+        this.delegate = checkNotNull(delegate);
+    }
 
     /**
      * Returns the specific subject to which this configuration pertains.
      *
      * @return configuration subject
      */
-    S subject() {
+    public S subject() {
         return subject;
     }
 
     /**
-     * Initializes the configuration behaviour with necessary context.
+     * Returns the configuration key. This is primarily aimed for use in
+     * composite JSON trees in external representations and has no bearing on
+     * the internal behaviours.
      *
-     * @param subject  configuration subject
-     * @param node     JSON object node where configuration data is stored
-     * @param mapper   JSON object mapper
-     * @param delegate delegate context
+     * @return configuration key
      */
-    public void init(S subject, ObjectNode node, ObjectMapper mapper,
-                     ConfigApplyDelegate<S> delegate) {
-        this.subject = checkNotNull(subject);
-        this.node = checkNotNull(node);
-        this.mapper = checkNotNull(mapper);
-        this.delegate = checkNotNull(delegate);
+    public String key() {
+        return key;
+    }
+
+    /**
+     * Returns the JSON node that contains the configuration data.
+     *
+     * @return JSON node backing the configuration
+     */
+    public ObjectNode node() {
+        return node;
     }
 
     /**
@@ -67,4 +93,142 @@
         delegate.onApply(this);
     }
 
+
+    // Miscellaneous helpers for interacting with JSON
+
+    /**
+     * Gets the specified property as a string.
+     *
+     * @param name         property name
+     * @param defaultValue default value if property not set
+     * @return property value or default value
+     */
+    protected String get(String name, String defaultValue) {
+        return node.path(name).asText(defaultValue);
+    }
+
+    /**
+     * Sets the specified property as a string or clears it if null value given.
+     *
+     * @param name  property name
+     * @param value new value or null to clear the property
+     * @return self
+     */
+    protected Config<S> setOrClear(String name, String value) {
+        if (value != null) {
+            node.put(name, value);
+        } else {
+            node.remove(name);
+        }
+        return this;
+    }
+
+    /**
+     * Gets the specified property as a boolean.
+     *
+     * @param name         property name
+     * @param defaultValue default value if property not set
+     * @return property value or default value
+     */
+    protected boolean get(String name, boolean defaultValue) {
+        return node.path(name).asBoolean(defaultValue);
+    }
+
+    /**
+     * Sets the specified property as a boolean or clears it if null value given.
+     *
+     * @param name  property name
+     * @param value new value or null to clear the property
+     * @return self
+     */
+    protected Config<S> setOrClear(String name, Boolean value) {
+        if (value != null) {
+            node.put(name, value.booleanValue());
+        } else {
+            node.remove(name);
+        }
+        return this;
+    }
+
+    /**
+     * Gets the specified property as a long.
+     *
+     * @param name         property name
+     * @param defaultValue default value if property not set
+     * @return property value or default value
+     */
+    protected long get(String name, long defaultValue) {
+        return node.path(name).asLong(defaultValue);
+    }
+
+    /**
+     * Sets the specified property as a long or clears it if null value given.
+     *
+     * @param name  property name
+     * @param value new value or null to clear the property
+     * @return self
+     */
+    protected Config<S> setOrClear(String name, Long value) {
+        if (value != null) {
+            node.put(name, value.longValue());
+        } else {
+            node.remove(name);
+        }
+        return this;
+    }
+
+    /**
+     * Gets the specified property as a double.
+     *
+     * @param name         property name
+     * @param defaultValue default value if property not set
+     * @return property value or default value
+     */
+    protected double get(String name, double defaultValue) {
+        return node.path(name).asDouble(defaultValue);
+    }
+
+    /**
+     * Sets the specified property as a double or clears it if null value given.
+     *
+     * @param name  property name
+     * @param value new value or null to clear the property
+     * @return self
+     */
+    protected Config<S> setOrClear(String name, Double value) {
+        if (value != null) {
+            node.put(name, value.doubleValue());
+        } else {
+            node.remove(name);
+        }
+        return this;
+    }
+
+    /**
+     * Gets the specified property as an enum.
+     *
+     * @param name         property name
+     * @param defaultValue default value if property not set
+     * @param enumClass    the enum class
+     * @return property value or default value
+     */
+    protected <E extends Enum<E>> E get(String name, E defaultValue, Class<E> enumClass) {
+        return Enum.valueOf(enumClass, node.path(name).asText(defaultValue.toString()));
+    }
+
+    /**
+     * Sets the specified property as a double or clears it if null value given.
+     *
+     * @param name  property name
+     * @param value new value or null to clear the property
+     * @return self
+     */
+    protected <E extends Enum> Config<S> setOrClear(String name, E value) {
+        if (value != null) {
+            node.put(name, value.toString());
+        } else {
+            node.remove(name);
+        }
+        return this;
+    }
 }
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigApplyDelegate.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigApplyDelegate.java
index 8bd6049..bcce280 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigApplyDelegate.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigApplyDelegate.java
@@ -21,13 +21,13 @@
  * Delegate for notification when configuration changes have been applied.
  */
 @Beta
-public interface ConfigApplyDelegate<S> {
+public interface ConfigApplyDelegate {
 
     /**
      * Processes changes applied to the specified configuration.
      *
      * @param config changed configuration
      */
-    void onApply(Config<S> config);
+    void onApply(Config config);
 
 }
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigFactory.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigFactory.java
index 37b51fd..673c7f3 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigFactory.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/ConfigFactory.java
@@ -21,24 +21,31 @@
 /**
  * Base abstract factory for creating configurations for the specified subject type.
  *
- * @param <S> subject class
+ * @param <S> type of subject
+ * @param <C> type of configuration
  */
 @Beta
-public abstract class ConfigFactory<S> {
+public abstract class ConfigFactory<S, C extends Config<S>> {
 
-    private final Class<S> subjectClass;
-    private final String key;
+    private final SubjectFactory<S> subjectFactory;
+    private final Class<C> configClass;
+    private final String configKey;
 
     /**
      * Creates a new configuration factory for the specified class of subjects
-     * and bound to the given subject configuration key.
+     * capable of generating the configurations of the specified class. The
+     * subject and configuration class keys are used merely as keys for use in
+     * composite JSON trees.
      *
-     * @param subjectClass subject class
-     * @param key          subject configuration key
+     * @param subjectFactory subject factory
+     * @param configClass  configuration class
+     * @param configKey    configuration class key
      */
-    protected ConfigFactory(Class<S> subjectClass, String key) {
-        this.subjectClass = subjectClass;
-        this.key = key;
+    protected ConfigFactory(SubjectFactory<S> subjectFactory,
+                            Class<C> configClass, String configKey) {
+        this.subjectFactory = subjectFactory;
+        this.configClass = configClass;
+        this.configKey = configKey;
     }
 
     /**
@@ -46,17 +53,28 @@
      *
      * @return subject type
      */
-    public Class<S> subjectClass() {
-        return subjectClass;
+    public SubjectFactory<S> subjectFactory() {
+        return subjectFactory;
     }
 
     /**
-     * Returns the key to which produced configurations should be bound.
+     * Returns the class of the configuration which this factory generates.
      *
-     * @return subject configuration key
+     * @return configuration type
      */
-    public String key() {
-        return key;
+    public Class<C> configClass() {
+        return configClass;
+    }
+
+    /**
+     * Returns the unique key (within subject class) of this configuration.
+     * This is primarily aimed for use in composite JSON trees in external
+     * representations and has no bearing on the internal behaviours.
+     *
+     * @return configuration key
+     */
+    public String configKey() {
+        return configKey;
     }
 
     /**
@@ -65,6 +83,6 @@
      *
      * @return new uninitialized configuration
      */
-    public abstract Config<S> createConfig();
+    public abstract C createConfig();
 
 }
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigEvent.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigEvent.java
new file mode 100644
index 0000000..e381f5a
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigEvent.java
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config;
+
+import org.onosproject.event.AbstractEvent;
+
+/**
+ * Describes network configuration event.
+ */
+public class NetworkConfigEvent extends AbstractEvent<NetworkConfigEvent.Type, Object> {
+
+    private final Class configClass;
+
+    /**
+     * Type of network configuration events.
+     */
+    public enum Type {
+        /**
+         * Signifies that network configuration was added.
+         */
+
+        CONFIG_ADDED,
+        /**
+         * Signifies that network configuration was updated.
+         */
+        CONFIG_UPDATED,
+
+        /**
+         * Signifies that network configuration was removed.
+         */
+        CONFIG_REMOVED
+    }
+
+    /**
+     * Creates an event of a given type and for the specified subject and the
+     * current time.
+     *
+     * @param type        event type
+     * @param subject     event subject
+     * @param configClass configuration class
+     */
+    public NetworkConfigEvent(Type type, Object subject, Class configClass) {
+        super(type, subject);
+        this.configClass = configClass;
+    }
+
+    /**
+     * Creates an event of a given type and for the specified subject and time.
+     *
+     * @param type        device event type
+     * @param subject     event subject
+     * @param configClass configuration class
+     * @param time        occurrence time
+     */
+    public NetworkConfigEvent(Type type, Object subject, Class configClass, long time) {
+        super(type, subject, time);
+        this.configClass = configClass;
+    }
+
+    /**
+     * Returns the class of configuration that has been changed.
+     *
+     * @return configuration class
+     */
+    public Class configClass() {
+        return configClass;
+    }
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigListener.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigListener.java
new file mode 100644
index 0000000..38a0079
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigListener.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config;
+
+import org.onosproject.event.EventListener;
+
+/**
+ * Entity capable of receiving network configuration related events.
+ */
+public interface NetworkConfigListener extends EventListener<NetworkConfigEvent> {
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigRegistry.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigRegistry.java
index 261e1bd..727d05a 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigRegistry.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigRegistry.java
@@ -20,7 +20,11 @@
 import java.util.Set;
 
 /**
- * Service for tracking network configuration factories.
+ * Service for tracking network configuration factories. It is the basis for
+ * extensibility to allow various core subsystems or apps to register their
+ * own configuration factories that permit use to inject additional meta
+ * information about how various parts of the network should be viewed and
+ * treated.
  */
 @Beta
 public interface NetworkConfigRegistry {
@@ -40,34 +44,32 @@
     void unregisterConfigFactory(ConfigFactory configFactory);
 
     /**
-     * Returns set of configuration factories available for the specified
+     * Returns set of all registered configuration factories.
+     *
+     * @return set of config factories
+     */
+    Set<ConfigFactory> getConfigFactories();
+
+    /**
+     * Returns set of all configuration factories registered for the specified
      * class of subject.
      *
      * @param subjectClass subject class
-     * @param <T> type of subject
+     * @param <S>          type of subject
+     * @param <C>          type of configuration
      * @return set of config factories
      */
-    <T> Set<ConfigFactory<T>> getConfigFactories(Class<T> subjectClass);
+    <S, C extends Config<S>> Set<ConfigFactory<S, C>> getConfigFactories(Class<S> subjectClass);
 
     /**
-     * Returns the configuration type registered for the specified
-     * subject type and key.
-     *
-     * @param subjectClass subject class
-     * @param configKey    configuration key
-     * @param <T> type of subject
-     * @return config factory
-     */
-    <T> ConfigFactory<T> getConfigFactory(Class<T> subjectClass, String configKey);
-
-    /**
-     * Returns the configuration type registered for the specified
-     * configuration class.
+     * Returns the configuration factory that produces the specified class of
+     * configurations.
      *
      * @param configClass configuration class
-     * @param <T> type of subject
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
      * @return config factory
      */
-    <T> ConfigFactory<T> getConfigFactory(Class<Config<T>> configClass);
+    <S, C extends Config<S>> ConfigFactory<S, C> getConfigFactory(Class<C> configClass);
 
 }
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigService.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigService.java
index dd88a16..fb0c48f 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigService.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigService.java
@@ -15,26 +15,59 @@
  */
 package org.onosproject.incubator.net.config;
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.annotations.Beta;
 
 import java.util.Set;
 
 /**
  * Service for tracking network configurations which specify how the discovered
- * network information should be interpreted and how the network should be
- * configured.
+ * network information should be interpreted and how the core or applications
+ * should act on or configure the network.
  */
 @Beta
 public interface NetworkConfigService {
 
     /**
+     * Returns the set of subject classes for which configuration may be
+     * available.
+     *
+     * @return set of subject classes
+     */
+    Set<Class> getSubjectClasses();
+
+    /**
+     * Returns the subject factory with the specified key.
+     *
+     * @param subjectKey subject class key
+     * @return subject class
+     */
+    SubjectFactory getSubjectFactory(String subjectKey);
+
+    /**
+     * Returns the subject factory for the specified class.
+     *
+     * @param subjectClass subject class
+     * @return subject class key
+     */
+    SubjectFactory getSubjectFactory(Class subjectClass);
+
+    /**
+     * Returns the configuration class with the specified key.
+     *
+     * @param configKey subject class name
+     * @return subject class
+     */
+    Class<? extends Config> getConfigClass(String configKey);
+
+    /**
      * Returns the set of subjects for which some configuration is available.
      *
      * @param subjectClass subject class
-     * @param <T> type of subject
+     * @param <S>          type of subject
      * @return set of configured subjects
      */
-    <T> Set<T> getSubjects(Class<T> subjectClass);
+    <S> Set<S> getSubjects(Class<S> subjectClass);
 
     /**
      * Returns the set of subjects for which the specified configuration is
@@ -42,20 +75,20 @@
      *
      * @param subjectClass subject class
      * @param configClass  configuration class
-     * @param <T> type of subject
+     * @param <S>          type of subject
+     * @param <C>          type of configuration
      * @return set of configured subjects
      */
-    <T> Set<T> getSubjects(Class<T> subjectClass, Class<Config<T>> configClass);
-
+    <S, C extends Config<S>> Set<S> getSubjects(Class<S> subjectClass, Class<C> configClass);
 
     /**
      * Returns all configurations for the specified subject.
      *
      * @param subject configuration subject
-     * @param <T> type of subject
+     * @param <S>     type of subject
      * @return set of configurations
      */
-    <T> Set<Config<T>> getConfigs(T subject);
+    <S> Set<? extends Config<S>> getConfigs(S subject);
 
     /**
      * Returns the configuration for the specified subject and configuration
@@ -63,9 +96,61 @@
      *
      * @param subject     configuration subject
      * @param configClass configuration class
-     * @param <T> type of subject
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
      * @return configuration or null if one is not available
      */
-    <T> Config<T> getConfig(T subject, Class<Config<T>> configClass);
+    <S, C extends Config<S>> C getConfig(S subject, Class<C> configClass);
 
+    /**
+     * Creates a new configuration for the specified subject and configuration
+     * class. If one already exists, it is simply returned.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     * @return configuration or null if one is not available
+     */
+    <S, C extends Config<S>> C addConfig(S subject, Class<C> configClass);
+
+    /**
+     * Applies configuration for the specified subject and configuration
+     * class using the raw JSON object. If configuration already exists, it
+     * will be updated.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param json        raw JSON node containing the configuration data
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     * @return configuration or null if one is not available
+     */
+    <S, C extends Config<S>> C applyConfig(S subject, Class<C> configClass,
+                                           ObjectNode json);
+
+    /**
+     * Clears any configuration for the specified subject and configuration
+     * class. If one does not exist, this call has no effect.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     */
+    <S, C extends Config<S>> void removeConfig(S subject, Class<C> configClass);
+
+    /**
+     * Adds the specified network config listener.
+     *
+     * @param listener network config listener
+     */
+    void addListener(NetworkConfigListener listener);
+
+    /**
+     * Removes the specified network config listener.
+     *
+     * @param listener network config listener
+     */
+    void removeListener(NetworkConfigListener listener);
 }
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigStore.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigStore.java
new file mode 100644
index 0000000..cd9e229
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigStore.java
@@ -0,0 +1,129 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.store.Store;
+
+import java.util.Set;
+
+/**
+ * Mechanism for distributing and storing network configuration information.
+ */
+public interface NetworkConfigStore extends Store<NetworkConfigEvent, NetworkConfigStoreDelegate> {
+
+    /**
+     * Adds a new configuration factory.
+     *
+     * @param configFactory configuration factory to add
+     */
+    void addConfigFactory(ConfigFactory configFactory);
+
+    /**
+     * Removes a configuration factory.
+     *
+     * @param configFactory configuration factory to remove
+     */
+    void removeConfigFactory(ConfigFactory configFactory);
+
+    /**
+     * Returns the configuration factory for the specified configuration class.
+     *
+     * @param configClass configuration class
+     * @param <S>         type of subject
+     * @param <C>          type of configuration
+     * @return configuration factory or null
+     */
+    <S, C extends Config<S>> ConfigFactory<S, C> getConfigFactory(Class<C> configClass);
+
+    /**
+     * Returns set of subjects of the specified class, which have some
+     * network configuration associated with them.
+     *
+     * @param subjectClass subject class
+     * @param <S>          type of subject
+     * @return set of subject
+     */
+    <S> Set<S> getSubjects(Class<S> subjectClass);
+
+    /**
+     * Returns set of subjects of the specified class, which have the
+     * specified class of network configuration associated with them.
+     *
+     * @param subjectClass subject class
+     * @param configClass  configuration class
+     * @param <S>          type of subject
+     * @param <C>          type of configuration
+     * @return set of subject
+     */
+    <S, C extends Config<S>> Set<S> getSubjects(Class<S> subjectClass, Class<C> configClass);
+
+    /**
+     * Returns set of configuration classes available for the specified subject.
+     *
+     * @param subject configuration subject
+     * @param <S>     type of subject
+     * @return set of configuration classes
+     */
+    <S> Set<Class<? extends Config<S>>> getConfigClasses(S subject);
+
+    /**
+     * Get the configuration of the given class and for the specified subject.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     * @return configuration object
+     */
+    <S, C extends Config<S>> C getConfig(S subject, Class<C> configClass);
+
+    /**
+     * Creates a new configuration of the given class for the specified subject.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     * @return configuration object
+     */
+    <S, C extends Config<S>> C createConfig(S subject, Class<C> configClass);
+
+    /**
+     * Applies configuration for the specified subject and configuration
+     * class using the raw JSON object. If configuration already exists, it
+     * will be updated.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param json        raw JSON node containing the configuration data
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     */
+    <S, C extends Config<S>> C applyConfig(S subject, Class<C> configClass,
+                                           ObjectNode json);
+
+    /**
+     * Clears the configuration of the given class for the specified subject.
+     *
+     * @param subject     configuration subject
+     * @param configClass configuration class
+     * @param <S>         type of subject
+     * @param <C>         type of configuration
+     */
+    <S, C extends Config<S>> void clearConfig(S subject, Class<C> configClass);
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigStoreDelegate.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigStoreDelegate.java
new file mode 100644
index 0000000..a77988d
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/NetworkConfigStoreDelegate.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config;
+
+import org.onosproject.store.StoreDelegate;
+
+/**
+ * Network configuration store delegate abstraction.
+ */
+public interface NetworkConfigStoreDelegate extends StoreDelegate<NetworkConfigEvent> {
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/SubjectFactory.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/SubjectFactory.java
new file mode 100644
index 0000000..3f7e6dc
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/SubjectFactory.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config;
+
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Base abstract factory for creating configuration subjects from their
+ * string key image.
+ *
+ * @param <S> subject class
+ */
+@Beta
+public abstract class SubjectFactory<S> {
+
+    private final Class<S> subjectClass;
+    private final String subjectKey;
+
+    /**
+     * Creates a new configuration factory for the specified class of subjects
+     * capable of generating the configurations of the specified class. The
+     * subject and configuration class keys are used merely as keys for use in
+     * composite JSON trees.
+     *
+     * @param subjectClass subject class
+     * @param subjectKey   subject class key
+     */
+    protected SubjectFactory(Class<S> subjectClass, String subjectKey) {
+        this.subjectClass = subjectClass;
+        this.subjectKey = subjectKey;
+    }
+
+    /**
+     * Returns the class of the subject to which this factory applies.
+     *
+     * @return subject type
+     */
+    public Class<S> subjectClass() {
+        return subjectClass;
+    }
+
+    /**
+     * Returns the unique key of this configuration subject class.
+     * This is primarily aimed for use in composite JSON trees in external
+     * representations and has no bearing on the internal behaviours.
+     *
+     * @return configuration key
+     */
+    public String subjectKey() {
+        return subjectKey;
+    }
+
+    /**
+     * Creates a configuration subject from its key image.
+     *
+     * @return configuration subject
+     */
+    public abstract S createSubject(String key);
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/AllowedEntityConfig.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/AllowedEntityConfig.java
new file mode 100644
index 0000000..6651ad4
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/AllowedEntityConfig.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config.basics;
+
+import org.onosproject.incubator.net.config.Config;
+
+/**
+ * Base abstraction for network entities for which admission into control
+ * domain can be selectively configured, e.g. devices, end-stations, links
+ */
+public abstract class AllowedEntityConfig<S> extends Config<S> {
+
+    private static final String ALLOWED = "allowed";
+
+    /**
+     * Indicates whether the element is allowed for admission into the control
+     * domain.
+     *
+     * @return true if element is allowed
+     */
+    public boolean isAllowed() {
+        return get(ALLOWED, true);
+    }
+
+    /**
+     * Specifies whether the element is to be allowed for admission into the
+     * control domain.
+     *
+     * @param isAllowed true to allow; false to forbid; null to clear
+     * @return self
+     */
+    public AllowedEntityConfig isAllowed(Boolean isAllowed) {
+        return (AllowedEntityConfig) setOrClear(ALLOWED, isAllowed);
+    }
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicDeviceConfig.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicDeviceConfig.java
new file mode 100644
index 0000000..c3eb099
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicDeviceConfig.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config.basics;
+
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+
+/**
+ * Basic configuration for network infrastructure devices.
+ */
+public class BasicDeviceConfig extends BasicElementConfig<DeviceId> {
+
+    public static final String TYPE = "type";
+    public static final String DRIVER = "driver";
+
+    /**
+     * Returns the device type.
+     *
+     * @return device type override
+     */
+    public Device.Type type() {
+        return get(TYPE, Device.Type.SWITCH, Device.Type.class);
+    }
+
+    /**
+     * Sets the device type.
+     *
+     * @param type device type override
+     * @return self
+     */
+    public BasicDeviceConfig type(Device.Type type) {
+        return (BasicDeviceConfig) setOrClear(TYPE, type);
+    }
+
+    /**
+     * Returns the device driver name.
+     *
+     * @return driver name of null if not set
+     */
+    public String driver() {
+        return get(DRIVER, subject.toString());
+    }
+
+    /**
+     * Sets the driver name.
+     *
+     * @param driverName new driver name; null to clear
+     * @return self
+     */
+    public BasicElementConfig driver(String driverName) {
+        return (BasicElementConfig) setOrClear(DRIVER, driverName);
+    }
+
+    // TODO: device port meta-data to be configured via BasicPortsConfig
+    // TODO: device credentials/keys
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicElementConfig.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicElementConfig.java
new file mode 100644
index 0000000..39f767a
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicElementConfig.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config.basics;
+
+/**
+ * Basic configuration for network elements, e.g. devices, hosts. Such elements
+ * can have a friendly name, geo-coordinates, logical rack coordinates and
+ * an owner entity.
+ */
+public abstract class BasicElementConfig<S> extends AllowedEntityConfig<S> {
+
+    public static final String NAME = "name";
+
+    public static final String LATITUDE = "latitude";
+    public static final String LONGITUDE = "longitude";
+
+    public static final String RACK_ADDRESS = "rackAddress";
+    public static final String OWNER = "owner";
+
+    /**
+     * Returns friendly label for the element.
+     *
+     * @return friendly label or element id itself if not set
+     */
+    public String name() {
+        return get(NAME, subject.toString());
+    }
+
+    /**
+     * Sets friendly label for the element.
+     *
+     * @param name new friendly label; null to clear
+     * @return self
+     */
+    public BasicElementConfig name(String name) {
+        return (BasicElementConfig) setOrClear(NAME, name);
+    }
+
+    /**
+     * Returns element latitude.
+     *
+     * @return element latitude; -1 if not set
+     */
+    public double latitude() {
+        return get(LATITUDE, -1.0);
+    }
+
+    /**
+     * Sets the element latitude.
+     *
+     * @param latitude new latitude; null to clear
+     * @return self
+     */
+    public BasicElementConfig latitude(Double latitude) {
+        return (BasicElementConfig) setOrClear(LATITUDE, latitude);
+    }
+
+    /**
+     * Returns element latitude.
+     *
+     * @return element latitude; -1 if not set
+     */
+    public double longitude() {
+        return get(LONGITUDE, -1.0);
+    }
+
+    /**
+     * Sets the element longitude.
+     *
+     * @param longitude new longitude; null to clear
+     * @return self
+     */
+    public BasicElementConfig longitude(Double longitude) {
+        return (BasicElementConfig) setOrClear(LONGITUDE, longitude);
+    }
+
+    /**
+     * Returns the element rack address.
+     *
+     * @return rack address; null if not set
+     */
+    public String rackAddress() {
+        return get(RACK_ADDRESS, null);
+    }
+
+    /**
+     * Sets element rack address.
+     *
+     * @param address new rack address; null to clear
+     * @return self
+     */
+    public BasicElementConfig rackAddress(String address) {
+        return (BasicElementConfig) setOrClear(RACK_ADDRESS, address);
+    }
+
+    /**
+     * Returns owner of the element.
+     *
+     * @return owner or null if not set
+     */
+    public String owner() {
+        return get(OWNER, null);
+    }
+
+    /**
+     * Sets the owner of the element.
+     *
+     * @param owner new owner; null to clear
+     * @return self
+     */
+    public BasicElementConfig owner(String owner) {
+        return (BasicElementConfig) setOrClear(OWNER, owner);
+    }
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicHostConfig.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicHostConfig.java
new file mode 100644
index 0000000..2f4b799
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicHostConfig.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config.basics;
+
+import org.onosproject.net.HostId;
+
+/**
+ * Basic configuration for network end-station hosts.
+ */
+public class BasicHostConfig extends BasicElementConfig<HostId> {
+
+    // TODO: determine what aspects of configuration to add for hosts
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicLinkConfig.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicLinkConfig.java
new file mode 100644
index 0000000..c881a7b
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/BasicLinkConfig.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config.basics;
+
+import org.onosproject.net.Link;
+import org.onosproject.net.LinkKey;
+
+import java.time.Duration;
+
+/**
+ * Basic configuration for network infrastructure link.
+ */
+public class BasicLinkConfig extends AllowedEntityConfig<LinkKey> {
+
+    public static final String TYPE = "type";
+    public static final String LATENCY = "latency";
+    public static final String BANDWIDTH = "bandwidth";
+
+    /**
+     * Returns the link type.
+     *
+     * @return link type override
+     */
+    public Link.Type type() {
+        return get(TYPE, Link.Type.DIRECT, Link.Type.class);
+    }
+
+    /**
+     * Sets the link type.
+     *
+     * @param type link type override
+     * @return self
+     */
+    public BasicLinkConfig type(Link.Type type) {
+        return (BasicLinkConfig) setOrClear(TYPE, type);
+    }
+
+    /**
+     * Returns link latency in terms of nanos.
+     *
+     * @return link latency; -1 if not set
+     */
+    public Duration latency() {
+        return Duration.ofNanos(get(LATENCY, -1));
+    }
+
+    /**
+     * Sets the link latency.
+     *
+     * @param latency new latency; null to clear
+     * @return self
+     */
+    public BasicElementConfig latency(Duration latency) {
+        Long nanos = latency == null ? null : latency.toNanos();
+        return (BasicElementConfig) setOrClear(LATENCY, nanos);
+    }
+
+    /**
+     * Returns link bandwidth in terms of Mbps.
+     *
+     * @return link bandwidth; -1 if not set
+     */
+    public long bandwidth() {
+        return get(BANDWIDTH, -1);
+    }
+
+    /**
+     * Sets the link bandwidth.
+     *
+     * @param bandwidth new bandwidth; null to clear
+     * @return self
+     */
+    public BasicElementConfig bandwidth(Long bandwidth) {
+        return (BasicElementConfig) setOrClear(BANDWIDTH, bandwidth);
+    }
+
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java
new file mode 100644
index 0000000..257bd27
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/config/basics/SubjectFactories.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.incubator.net.config.basics;
+
+import org.onosproject.core.ApplicationId;
+import org.onosproject.incubator.net.config.SubjectFactory;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.HostId;
+import org.onosproject.net.LinkKey;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Set of subject factories for potential configuration subjects.
+ */
+public final class SubjectFactories {
+
+    // Construction forbidden
+    private SubjectFactories() {
+    }
+
+    public static final SubjectFactory<ApplicationId> APP_SUBJECT_FACTORY =
+            new SubjectFactory<ApplicationId>(ApplicationId.class, "apps") {
+                @Override
+                public ApplicationId createSubject(String key) {
+                    // FIXME: figure out how to safely create sanctioned app ids
+                    return null;
+                }
+            };
+
+    public static final SubjectFactory<DeviceId> DEVICE_SUBJECT_FACTORY =
+            new SubjectFactory<DeviceId>(DeviceId.class, "devices") {
+                @Override
+                public DeviceId createSubject(String key) {
+                    return DeviceId.deviceId(key);
+                }
+            };
+
+    public static final SubjectFactory<HostId> HOST_SUBJECT_FACTORY =
+            new SubjectFactory<HostId>(HostId.class, "hosts") {
+                @Override
+                public HostId createSubject(String key) {
+                    return HostId.hostId(key);
+                }
+            };
+
+    public static final SubjectFactory<LinkKey> LINK_SUBJECT_FACTORY =
+            new SubjectFactory<LinkKey>(LinkKey.class, "links") {
+                @Override
+                public LinkKey createSubject(String key) {
+                    String[] cps = key.split("-");
+                    checkArgument(cps.length == 2, "Incorrect link key format: %s", key);
+                    return LinkKey.linkKey(ConnectPoint.deviceConnectPoint(cps[0]),
+                                           ConnectPoint.deviceConnectPoint(cps[1]));
+                }
+            };
+
+}