基于floodlight开发SDN应用实例

根据release note来看，主要最大的更新在于添加了对于of1.3的支持。虽然我尚未验证（后续会验证）floodlight对of1.3的支持程度，但是release note中的这句话：“ and work with OpenFlow 1.3 features such as groups and meters.”。我猜测大概是能够识别组表和计量表，但是不作处理。OTZ……还有就是以往一些小bug的修复，最直观的就是页面的改进。拓扑结构、ip、流表等信息不再像以往一样显不显示得看脸，可以实时准确的显示出来。

下面是具体的添加模块的实验。

导入工程：

从git上直接拉下来的代码是没法直接导入到eclipse中的，需要添加.project文件和,classpath文件：

Project文件：

 xml version="1.0" encoding="UTF-8"?>
     <projectDescription>
         <name>floodlightname>
         <comment>comment>
         <projects>
         projects>
         <buildSpec>
             <buildCommand>
                 <name>org.python.pydev.PyDevBuildername>
                 <arguments>
                 arguments>
             buildCommand>
             <buildCommand>
                 <name>org.eclipse.jdt.core.javabuildername>
                 <arguments>
                 arguments>
              buildCommand>
         buildSpec>
         <natures>
             <nature>org.eclipse.jdt.core.javanaturenature>
             <nature>org.python.pydev.pythonNaturenature>
         natures>
 projectDescription>

Classpath文件：

 xml version="1.0" encoding="UTF-8"?>
 <classpath>
     <classpathentry kind="src" output="target/bin" path="src/main/java"/>
     <classpathentry kind="src" path="src/main/resources"/>
     <classpathentry kind="src" output="target/bin-test" path="src/test/java"/>
     <classpathentry kind="src" path="src/test/resources"/>
     <classpathentry kind="src" output="target/bin" path="lib/gen-java"/>
     <classpathentry exported="true" kind="lib" path="lib/args4j-2.0.16.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/cglib-nodep-2.2.2.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/concurrentlinkedhashmap-lru-1.2.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/derby-10.9.1.0.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/findbugs-annotations-2.0.1.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/findbugs-jsr305-2.0.1.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/guava-13.0.1.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-annotations-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-core-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-databind-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-dataformat-csv-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-dataformat-smile-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-dataformat-xml-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jackson-dataformat-yaml-2.1.4.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/junit-4.8.2.jar" sourcepath="C:/Users/dell/.m2/repository/junit/junit/4.8.2/junit-4.8.2-sources.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/jython-2.5.2.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/libthrift-0.9.0.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/logback-classic-1.0.0.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/logback-core-1.0.0.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/netty-3.2.6.Final.jar" sourcepath="C:/Users/dell/.m2/repository/org/jboss/netty/netty/3.2.6.Final/netty-3.2.6.Final-sources.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/objenesis-1.2.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/org.easymock-3.1.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/org.restlet-2.2M3.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/org.restlet.ext.jackson-2.2M3.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/org.restlet.ext.simple-2.2M3.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/org.restlet.ext.slf4j-2.2M3.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/simple-5.1.1.jar"/>
     <classpathentry exported="true" kind="lib" path="lib/slf4j-api-1.6.4.jar"/>
     <classpathentry kind="lib" path="lib/asm-3.0.jar"/>
     <classpathentry kind="lib" path="lib/asm-tree-3.0.jar"/>
     <classpathentry kind="lib" path="lib/cobertura-1.9.4.1.jar"/>
     <classpathentry kind="lib" path="lib/hamcrest-core-1.3.jar"/>
     <classpathentry kind="lib" path="lib/hamcrest-integration-1.3.jar"/>
     <classpathentry kind="lib" path="lib/hamcrest-library-1.3.jar"/>
     <classpathentry kind="lib" path="lib/j3dutils.jar"/>
     <classpathentry kind="lib" path="lib/jdeb-1.0.1.jar"/>
     <classpathentry kind="lib" path="lib/log4j-1.2.9.jar"/>
     <classpathentry kind="lib" path="lib/openflowj-0.9.0-SNAPSHOT-javadoc.jar"/>
     <classpathentry kind="lib" path="lib/openflowj-0.9.0-SNAPSHOT-sources.jar"/>
     <classpathentry kind="lib" path="lib/openflowj-0.9.0-SNAPSHOT.jar"/>
     <classpathentry kind="lib" path="lib/packetstreamer-thrift.jar"/>
     <classpathentry kind="lib" path="lib/oro/jakarta-oro-2.0.8.jar"/>
     <classpathentry exported="true" kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
     <classpathentry kind="output" path="target/bin"/>
 classpath>

然后就可以作为普通的项目导入即可。

实验过程：

这里的实验做的是对packet-in包的数量进行统计并打印到控制台，功能单一，但能体现出添加新模块的整个流程。

 

1.添加新服务接口

首先需要定义新加模块服务的接口：

 package net.floodlightcontroller.statics;

 import net.floodlightcontroller.core.module.IFloodlightService;

 /**
  * The service registry
  * @author yangshuai
  */

 public interface IPktinHistoryService extends IFloodlightService {
     /*
      * 用于统计结果
      */
     public long getPackINCount();
 }

2.添加PktinHistory模块：因为这里添加的新模块的功能比较单一，只是统计floodlight运行后packet-in包的总数量，并且是持续累计计数的，所以只需在该接口中定义一个用于计算的方法就可以了。

定义PktinHistory模块：

 package net.floodlightcontroller.statics;

 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;

 import org.projectfloodlight.openflow.protocol.OFMessage;
 import org.projectfloodlight.openflow.protocol.OFType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import net.floodlightcontroller.core.FloodlightContext;
 import net.floodlightcontroller.core.IFloodlightProviderService;
 import net.floodlightcontroller.core.IOFMessageListener;
 import net.floodlightcontroller.core.IOFSwitch;
 import net.floodlightcontroller.core.module.FloodlightModuleContext;
 import net.floodlightcontroller.core.module.FloodlightModuleException;
 import net.floodlightcontroller.core.module.IFloodlightModule;
 import net.floodlightcontroller.core.module.IFloodlightService;
 import net.floodlightcontroller.restserver.IRestApiService;

 /*
  *
  *@author yangshuai
  */

 public class PktinHistory implements
     IOFMessageListener,IFloodlightModule,IPktinHistoryService{

     protected static Logger log = LoggerFactory.getLogger(PktinHistory.class);
     protected IFloodlightProviderService FloodlightProvider ;
     protected IRestApiService restApi ;
     private AtomicLong PACKET_IN_COUNT = new AtomicLong() ;

     @Override
     public String getName() {
         return "PktinHistory" ;
     }

     @Override
     public boolean isCallbackOrderingPrereq(OFType type, String name) {
         // TODO Auto-generated method stub
         return false;
     }

     @Override
     public boolean isCallbackOrderingPostreq(OFType type, String name) {
         // TODO Auto-generated method stub
         return false;
     }

     @Override
     public long getPackINCount() {
         return PACKET_IN_COUNT.get();
     }

     @Override
     public Collection<Class extends IFloodlightService>> getModuleServices() {
         Collection<Class extends IFloodlightService>> l =
                 new ArrayList<Class extends IFloodlightService>>();
         l.add(IPktinHistoryService.class);
         return l;
     }

     @Override
     public Map<Class extends IFloodlightService>, IFloodlightService> getServiceImpls() {
         Map<Class extends IFloodlightService>,IFloodlightService> m =
                 new  HashMap<Class extends IFloodlightService>,IFloodlightService>();
         m.put(IPktinHistoryService.class,this);
         return m;
     }

     @Override
     public Collection<Class extends IFloodlightService>> getModuleDependencies() {
         Collection<Class extends IFloodlightService>> l =
                 new ArrayList<Class extends IFloodlightService>>() ;
         l.add(IFloodlightProviderService.class);
         l.add(IRestApiService.class);
         return l ;
     }

     @Override
     public void init(FloodlightModuleContext context)
             throws FloodlightModuleException {
         FloodlightProvider = context.getServiceImpl(IFloodlightProviderService.class);
         restApi = context.getServiceImpl(IRestApiService.class) ;
     }

     @Override
     public void startUp(FloodlightModuleContext context)
             throws FloodlightModuleException {
         FloodlightProvider.addOFMessageListener(OFType.PACKET_IN,this) ;
     }

     @Override
     public net.floodlightcontroller.core.IListener.Command receive(
             IOFSwitch sw, OFMessage msg, FloodlightContext cntx) {
         long count = PACKET_IN_COUNT.incrementAndGet() ;
         log.info("The total count of packet-in Messages are" + count);
         return Command.CONTINUE ;
     }

 }

在floodlight中所有的模块都必须实现IFloodlightModule接口，而这里新添加的模块需要监听数据包，所以也需要实现IOFMessageListener接口。IOFMessageListener接口用于监听Packet-in消息，并记录消息递增数量，IPktinHistoryService接口是业务查询接口，提供Packet-in数据分组统计结果查询服务，IFloodLightModule接口标识该类是一个floodlight模块，继承该接口的类会在floodlight启动过程中以模块形式加载。该类文件可以随意添加到任何包中，为了方便管理和演示，这里将所有添加该模块所新建的文件全都放在了新建包net.floodlightcontroller.statics中。这个路劲在后面修改配置文件中仍然会使用到。

 

3.rest资源定义

在完成模块的定义之后，需要对rest服务资源进行定义，这里将类名定义为：PktInHistoryResource，继承抽象类ServerResource（ServerResource是Java轻量级REST框架Restlet的抽象类），并实现业务逻辑。该步主要功能是将Packet-in统计接口包装为REST资源便于后续资源绑定。

 package net.floodlightcontroller.statics;

 import java.util.HashMap;
 import org.restlet.resource.Get;
 import org.restlet.resource.ServerResource;

 /*
  *
  *@author yangshuai
  */

 public class PktInHistoryResource extends ServerResource{
     @Get("json")

     public HashMap<String, String> retrieve(){
         IPktinHistoryService pihr = (IPktinHistoryService) getContext()
                 .getAttributes().get(IPktinHistoryService.class.getCanonicalName());
         long count = pihr.getPackINCount();
         HashMap<String, String> resp = new HashMap<String, String>() ;
         resp.put("Total", Long.toString(count)) ;
         return resp;
     }
 }

4.绑定url与rest资源

接着定义PktInHistoryWebRoutable类，将上步定义的PktInHistoryResource资源与访问路径绑定。该类中定义的路径包括外部获取该REST资源的基本路径和相对路径。

 package net.floodlightcontroller.statics;

 import net.floodlightcontroller.restserver.RestletRoutable;

 import org.restlet.Context;
 import org.restlet.Restlet;
 import org.restlet.routing.Router;

 /*
  *
  *@author yangshuai
  */

 public class PktInHistoryWebRoutable implements RestletRoutable{

     public Restlet getRestlet(Context context){
         Router router =new Router(context) ;
         router.attach("/pktinhistory/json", PktInHistoryResource.class) ;
         return router ;
     }

     public String basePath(){
         return "/vm/statics" ;
     }
 }

5.资源发布 

资源绑定相应路径后需要在REST服务中发布，因此还需要在PktinHistory的startUp方法中注册PktInHistoryWebRoutable，表明有新的资源加入REST服务。

 @Override
     public void init(FloodlightModuleContext context)
             throws FloodlightModuleException {
         FloodlightProvider = context.getServiceImpl(IFloodlightProviderService.class);
         restApi = context.getServiceImpl(IRestApiService.class) ;
     }

6.定义完上述源码后还需要在配置文件中指定新增模块名，该配置文件为resources/META-INF/services/net.FloodLight.core.module.IFloodLightModule，这里就是添加net.FloodLightcontroller.statics.PktinHistory模块配置信息。该配置文件是FloodLight模块加载系统中加载模块类的依据，用于告知控制器要加载那些模块。 

7.除上述配置外，还需要在resources/floodlightdefault.properties中的floodlight.modules配置参数后追加新增模块名（net.FloodLight.controller.statics.PktinHistory 注：这里就要根据添加的PktinHistory 类的具体路径进行修改），表明该配置启动时必须加载。

 

实验成果截图：

问题：

在floodlight的显示界面上的监听端口为6633，在1.0以前的版本中，mininet连接到floodlight远程控制器时指定的端口号也是6633。但是在floodlight1.0版本的测试时，是使用6653端口连接上的。