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Diffstat (limited to 'doc/source/writing_ryu_app.rst')
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1 files changed, 24 insertions, 24 deletions
diff --git a/doc/source/writing_ryu_app.rst b/doc/source/writing_ryu_app.rst index 8f8556bb..7f15ed9a 100644 --- a/doc/source/writing_ryu_app.rst +++ b/doc/source/writing_ryu_app.rst @@ -5,21 +5,21 @@ The First Application Whetting Your Appetite ====================== -If you want to manage the network gears (switches, routers, etc) at -your way, you need to write your Ryu application. Your application -tells Ryu how you want to manage the gears. Then Ryu configures the -gears by using OpenFlow protocol, etc. +If you want to manage network gear (switches, routers, etc) your +own way, you just need to write your own Ryu application. Your application +tells Ryu how you want to manage the gear. Then Ryu configures the +gear by using OpenFlow protocol, etc. -Writing Ryu application is easy. It's just Python scripts. +Writing Ryu applications is easy. They're just Python scripts. Start Writing ============= -We show a Ryu application that make OpenFlow switches work as a dumb +Here we show a Ryu application that makes an OpenFlow switch work as a dumb layer 2 switch. -Open a text editor creating a new file with the following content: +Open a text editor and create a new file with the following content: .. code-block:: python @@ -29,9 +29,9 @@ Open a text editor creating a new file with the following content: def __init__(self, *args, **kwargs): super(L2Switch, self).__init__(*args, **kwargs) -Ryu application is just a Python script so you can save the file with -any name, extensions, and any place you want. Let's name the file -'l2.py' at your home directory. +Ryu applications are just Python scripts so you can save the file with +any name, any extension, and any place you want. Let's name the file +'l2.py' in your home directory. This application does nothing useful yet, however it's a complete Ryu application. In fact, you can run this Ryu application:: @@ -41,10 +41,10 @@ application. In fact, you can run this Ryu application:: instantiating app /Users/fujita/l2.py -All you have to do is defining needs a new subclass of RyuApp to run +All you have to do is define a new subclass of RyuApp to run your Python script as a Ryu application. -Next let's add the functionality of sending a received packet to all +Next let's add some functionality that sends a received packet to all the ports. .. code-block:: python @@ -75,18 +75,18 @@ the ports. dp.send_msg(out) -A new method 'packet_in_handler' is added to L2Switch class. This is -called when Ryu receives an OpenFlow packet_in message. The trick is +A new method 'packet_in_handler' is added to the L2Switch class. This is +called when Ryu receives an OpenFlow packet_in message. The trick is the 'set_ev_cls' decorator. This decorator tells Ryu when the decorated function should be called. -The first argument of the decorator indicates an event that makes -function called. As you expect easily, every time Ryu gets a +The first argument of the decorator indicates which type of event this +function should be called for. As you might expect, every time Ryu gets a packet_in message, this function is called. -The second argument indicates the state of the switch. Probably, you +The second argument indicates the state of the switch. You probably want to ignore packet_in messages before the negotiation between Ryu -and the switch finishes. Using 'MAIN_DISPATCHER' as the second +and the switch is finished. Using 'MAIN_DISPATCHER' as the second argument means this function is called only after the negotiation completes. @@ -103,20 +103,20 @@ Ready for the second half. * OFPActionOutput class is used with a packet_out message to specify a switch port that you want to send the packet out of. This - application need a switch to send out of all the ports so OFPP_FLOOD - constant is used. + application uses the OFPP_FLOOD flag to indicate that the packet should + be sent out on all ports. * OFPPacketOut class is used to build a packet_out message. * If you call Datapath class's send_msg method with a OpenFlow message - class object, Ryu builds and send the on-wire data format to the switch. + class object, Ryu builds and sends the on-wire data format to the switch. -Here, you finished implementing your first Ryu application. You are ready to -run this Ryu application that does something useful. +There, you finished implementing your first Ryu application. You are ready to +run a Ryu application that does something useful. -A dumb l2 switch is too dumb? You want to implement a learning l2 +Is a dumb L2 switch is too dumb? You want to implement a learning L2 switch? Move to `the next step <https://github.com/osrg/ryu/blob/master/ryu/app/simple_switch.py>`_. You can learn from the existing Ryu applications at `ryu/app |