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  • Device and device port types and names
  • Device location, owner, hardware and software versions
  • Wether Whether components are allowed or denied inclusion in the network model

The configurations may refer to a component that may or may not already exist in the network representation (i.e., the system may/may not have discovered it in the network). This implies that an application can offer hints about a yet-to-be-discovered component, as well as modify a known component’s attributes.

This subsystem likewise serves as a shim between the system’s network representation, and the means to configure it. Currently, JSON is the preferred means to describe component configurations.

 

Terminology

  • A subject is a reference to, or a placeholder for, an object to be configured via this subsystem. Example: a DeviceId for a network device, or a ConnectPoint

...

  • for a device port.

  • A config is a set of exposed tunables for a given object. Example: A BasicDeviceConfig allows a device’s type and southbound driver to be set/changed.

  • A key, or subject key, is a string name for a subject. It is used as the key for the JSON field containing the configuration values. Example: Device configurations can be found in the field with key “devices”.

  • A config key is a string name for a configuration class. It is also used as a JSON field key. Example: the key “basic” refers to the general configurations allowed for a device. The value associated with it may be a JSON representation of config values.

  • A config operator reconciles different sources of network configuration information for a given object. Sources include descriptions (from Providers), configs (from this subsystem), and intents (from applications).

Image Added

 

Components
Anchor
components
components

  • A subject is a Java object used as an unique identifier for a network object. Its stringified form is used as a JSON field key tied to the configurations associated with the network object.

    Example: A Link can be uniquely identified by a LinkKey (a pair of endpoints), so we use that as its subject. A LinkKey can be represented by a string of format “deviceId/port-deviceId/port”, and conversely, such a string can be used to generate a LinkKey.

  • Config subclasses implement the tunables for a subject as a set of getters and setters (attribute accessors) to JSON object constructs (ObjectNodes).

    Example: An OpticalPortConfig is defined as:

     

    Code Block
    languagejava
    public class OpticalPortConfig extends Config<ConnectPoint>

     

    meaning that it manipulates the configurations associated with ConnectPoint subjects (optical device ports). Some of its attribute accessors include the port’s string and numeric names, and the number of channels that the port supports.

  • SubjectFactory ties a subject to its subject key, and generates objects that represent the subject.

    Example: the factory that generates ConnectPoints is instantiated as:

     

    Code Block
    languagejava
    public static final SubjectFactory<ConnectPoint> CONNECT_POINT_SUBJECT_FACTORY =
      
    
    new SubjectFactory<ConnectPoint>(ConnectPoint.class, "ports") {
      @Override 
    
        @Override
        public ConnectPoint createSubject(String key) {
            
    return ConnectPoint.deviceConnectPoint(key);
      }  
    
        }
    };

     

    meaning that the key for the JSON field containing port information is keyed on string “ports”, and the factory can create ConnectPoints from a “deviceId:port” string (the argument to createSubject).

  • ConfigFactory ties a subject to its config and config key, and generates Configs.

    Example: The ConfigFactory for OpticalPortConfig is defined as:

     

    Code Block
    languagejava
    // ConfigFactory<S, C extends
    Config<S>> 
    Config<S>>
new ConfigFactory<ConnectPoint, OpticalPortConfig>(CONNECT_POINT_SUBJECT_FACTORY,
                                                   OpticalPortConfig.class,
    "basic
                                                      "optical") {
    @Override 
        @Override
    public OpticalPortConfig createConfig() {
        return new OpticalPortConfig();
     
    
    }
     
    
}

     

    indicating that the this ConfigFactory can generate OpticalPortConfigs, and the configuration information for a given optical port can be fetched from the subsystem’s manager using its associated subject (a ConnectPoint in this case). In the JSON structure, the key “basic” can be used to fetch out the values set by the OpticalPortConfig.

  • ConfigOperator implementations are classes that implement the policy for merging information from different sources, and conversions between these sources.

    Example: The BasicLinkOperator defines methods for merging the contents of BasicLinkConfigs and LinkDescriptions, and for converting Link objects and BasicLinkConfigs into LinkDescriptions understood by the core.

Configuration Syntax

The relationship between the subject, config, subject key, and config key are summarized by the following JSON tree:

Code Block
languagetext
{
    subject key 1 : {
        subject key 1 : {
            config subjectkey 1 : {
              config  keyattr1 : {value1,
                attr2 : value2,
 config fields
              }...
            },
          subject  config key 2 : {
                ...
            }
        },
        subject key2 2: {
          ...
    },
    subject key 2 {
  }

...

  ...
}

For example, a configuration for a single device might the device identified by the ID (subject) of:0000ffffffffff0a might look like the following:

Code Block
languagetext
  {
     "devices" : {
        "of:0000ffffffffff0a" : {
            "basic": {
                "driver": "linc-oe",
                "type": "ROADM",
                "latitude": 33.8,
                "name": "ATL-S10",
                "longitude": -84.1
            }
        }
     }
  }

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Indeed, 
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 if 
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 you 
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 were 
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 to 
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 take 
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 a 
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 look 
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 at BasicDeviceConfig and 
...
 its 
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 superclass, 
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 you 
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 will 
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 find 
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 all 
...
 of 
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 the 
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 fields 
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 within 
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 the 
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 “basic” 
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 clause 
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 above 
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defined in those two classes.
Using Network Configuration Services
...
...
Making objects configurable
The network configuration subsystem can be used to configure arbitrary network objects. For an object to be configurable through this subsystem, you must implement the components described in Components. Some things to note are:
  • SubjectFactory implementations belong in SubjectFactories. While you may want to use an existing factory for your subject of choice, you may want to implement a new SubjectFactory in addition to an existing one if a different key/creation technique is required for a subject.
  • A ConfigFactory must be registered with the NetworkConfigManager. Adding a ConfigFactory to BasicNetworkConfigs will cause it to be registered when the subsystem starts up. Alternatively, you may manually invoke 
  • NetworkConfigManager.registerConfigFactory() from the application
...
REST API
The NetworkConfigWebResource implements the REST calls for the network configuration subsystem. Its functionalities will eventually replace that of ConfigWebResource.
The following example uses the REST API to upload a configuration file
  • :
 
  •  Code Block
    language
bash
curl --user onos:rocks -X POST -H "Content-Type: application/json" http://192.168.56.111:8181/onos/v1/network/configuration/ -d @/tmp/cfg.json
 
The above assumes a running instance at 192.168.56.111, and a configuration file at /tmp/cfg.json. They should be replaced with appropriate values.
Likewise, the user:password vaues may differ with your setup; Other common values are karaf:karaf and onos:onos.
 
Network Configuration Loader
The NetworkConfigLoader reads JSON files from a known location and attempts to load them as network configurations.
Currently, a file named network-cfg.json is picked up from ${ONOS_ROOT}/tools/package/config/ and placed in ${KARAF_ROOT}../config/ (currently fixed) at deployment. When the remote instance boots, its network configuration loader runtime will read this file.
The Network Configuration Loader is implemented as a listener for Network Configuration events (NetworkConfigEvents). It attempts to use the knwon Configs in order to generate or update entities in the network model once it is notified that the Configs are available.
  • java
    // in the application:
@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
protected NetworkConfigRegistry registry;

private ConfigFactory configFactory =
        new ConfigFactory(SubjectFactories.FOO_SUBJECT_FACTORY, FooConfig.class, "foo") {
    @Override
    public FooConfig createConfig() {
        return new FooConfig();
    }
};

public void register() {
    registry.registerConfigFactory(configFactory);
}
  • ConfigOperators enforce an order of precedence on information depending on their source. As a general rule, the configs supplied by this subsystem override information supplied by providers.
Using the service from applications
As with other services, the two primary ways that an application can use the network configuration subsystem are:
  • Registering as a NetworkConfigListener : this enables the listener to receive NetworkConfigEvents whenever configurations are added, removed, or modified.
  • Requesting configuarations with getConfig() : an application can fetch the config tied to a certain network element given its subject and a Config class:
     Code Block
    languagejava
    public void doConfigThings(Device dev) {
    // a Device's subject is its ID
    DeviceId devId = dev.id();
    BasicDeviceConfig bdc = configService.getConfig(devId, BasicDeviceConfig.class);

    // a attribute of a device is if it's allowed in the network model
    if (!bdc.isAllowed()) {
        log.warn("This device isn't allowed here!");
        removeDevice(devId);
    }
}
...