[Ryu-devel] Adding REST to Ryu

Discussion:

Douglas Harewood-Gill

2017-06-06 12:18:25 UTC

Fujimoto Satoshi

2017-06-07 00:15:07 UTC

Hi, Douglas

Ryu has ofctl_rest.py, which is a sample application and provides REST
API to get flow statistics.
http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html

I think it is better to use ofctl_rest.py than to implement your own
REST API in your app.

Thanks,
Fujimoto

Post by Douglas Harewood-Gill
Greetings I am a PhD student new to both Python and Ryu and I was
wondering if anyone could give me some advice.
I am using the Ryu controller program (L2DestForwardStaticRyu.py)
provided by Dr Grey Bernstein
(https://www.grotto-networking.com/SDNfun.html#programming-switches-with-ryu)
for shortest path computation for a full Mesh network in Mininet but
the example provided does not include REST which I require to be able
to collect flow statistics such as the flows in each router,
bandwidth, latency, etc.
Unfortunately I have been looking and with the exception of
(https://osrg.github.io/ryu-book/en/html/rest_api.html) which seems
overly specific, I am unable to find a good example that would allow
me to work out how to integrate REST into the above Ryu control program.
So if anyone can point me in the right direction or can provide some
examples, I would be most grateful.
Thank you for your time.
Best Regards
Douglas
--
*Douglas Harewood-Gill MSc MIET*
CDT Student in Communications (PhD), University of Bristol
Post-Graduate Student (Taught and Research)
*
CDT Communications*
University of Bristol, Merchant Venturers' Building, Woodland Road,
Clifton, Bristol. BS8 1UB
http://www.bristol.ac.uk/
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Ryu-devel mailing list
https://lists.sourceforge.net/lists/listinfo/ryu-devel

Douglas Harewood-Gill

2017-06-07 11:21:58 UTC

Permalink

Post by Fujimoto Satoshi
Hi, Douglas
Ryu has ofctl_rest.py, which is a sample application and provides REST API
to get flow statistics.
http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html
I think it is better to use ofctl_rest.py than to implement your own REST
API in your app.
Thanks,
Fujimoto
Greetings I am a PhD student new to both Python and Ryu and I was
wondering if anyone could give me some advice.
I am using the Ryu controller program (L2DestForwardStaticRyu.py) provided
by Dr Grey Bernstein (https://www.grotto-networking.com/SDNfun.html#
programming-switches-with-ryu) for shortest path computation for a full
Mesh network in Mininet but the example provided does not include REST
which I require to be able to collect flow statistics such as the flows in
each router, bandwidth, latency, etc.
Unfortunately I have been looking and with the exception of (
https://osrg.github.io/ryu-book/en/html/rest_api.html) which seems overly
specific, I am unable to find a good example that would allow me to work
out how to integrate REST into the above Ryu control program.
So if anyone can point me in the right direction or can provide some
examples, I would be most grateful.
Thank you for your time.
Best Regards
Douglas
--
*Douglas Harewood-Gill MSc MIET*
CDT Student in Communications (PhD), University of Bristol
Post-Graduate Student (Taught and Research)
* CDT Communications*
University of Bristol, Merchant Venturers' Building, Woodland Road,
Clifton, Bristol. BS8 1UB
http://www.bristol.ac.uk/
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________

--
*Douglas Harewood-Gill MSc MIET*
CDT Student in Communications (PhD), University of Bristol
Post-Graduate Student (Taught and Research)
e-mail: douglas.harewood-***@bristol.ac.uk

*CDT Communications*

University of Bristol, Merchant Venturers' Building, Woodland Road,
Clifton, Bristol. BS8 1UB

http://www.bristol.ac.uk/

Iwase Yusuke

2017-06-08 00:27:09 UTC

Permalink

Hi Douglas,

Excuse me for cutting in.

Just for getting flow statistics, how about running your app and ofctl_rest
together as Fujimoto said.
e.g.)
$ ryu-manager your_app.py ryu.app.ofctl_rest

If you want to implement your own REST APIs on your app, Ryu-Book is the
most helpful as far as I know.
(You might already be aware of this though...)
http://osrg.github.io/ryu-book/en/html/rest_api.html

FYI, here is an sample implementation on simple_switch_13.py for getting
flow statistics.
The usage of "WSGI" framework is described on Ryu-Book.

$ git diff
diff --git a/ryu/app/simple_switch_13.py b/ryu/app/simple_switch_13.py
index 3e7c598..f33e474 100644
--- a/ryu/app/simple_switch_13.py
+++ b/ryu/app/simple_switch_13.py
@@ -13,6 +13,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.

+import json
+
from ryu.base import app_manager
from ryu.controller import ofp_event
from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
@@ -21,14 +23,26 @@ from ryu.ofproto import ofproto_v1_3
from ryu.lib.packet import packet
from ryu.lib.packet import ethernet
from ryu.lib.packet import ether_types
+from ryu.app.ofctl import api as ofctl_api
+from ryu.app.wsgi import ControllerBase
+from ryu.app.wsgi import Response
+from ryu.app.wsgi import route
+from ryu.app.wsgi import WSGIApplication
+
+
+_URI_PREFIX = '/simpleswitch/stats/{dpid}'

class SimpleSwitch13(app_manager.RyuApp):
OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
+ _CONTEXTS = {'wsgi': WSGIApplication}

def __init__(self, *args, **kwargs):
super(SimpleSwitch13, self).__init__(*args, **kwargs)
self.mac_to_port = {}
+ wsgi = kwargs['wsgi']
+ wsgi.register(SimpleSwitchController,
+ {SimpleSwitch13.__name__: self})

@set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
def switch_features_handler(self, ev):
@@ -117,3 +131,32 @@ class SimpleSwitch13(app_manager.RyuApp):
out = parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id,
in_port=in_port, actions=actions, data=data)
datapath.send_msg(out)
+
+ def get_flow_stats(self, dpid):
+ datapath = ofctl_api.get_datapath(self, dpid)
+ if datapath is None:
+ return None
+
+ parser = datapath.ofproto_parser
+ req = parser.OFPFlowStatsRequest(datapath)
+
+ rep = ofctl_api.send_msg(
+ app=self, msg=req,
+ reply_cls=parser.OFPFlowStatsReply, reply_multi=True)
+ return [r.to_jsondict() for r in rep]
+
+
+class SimpleSwitchController(ControllerBase):
+
+ def __init__(self, req, link, data, **config):
+ super(SimpleSwitchController, self).__init__(req, link, data, **config)
+ self.simple_switch_app = data[SimpleSwitch13.__name__]
+
+ @route('simpleswitch', _URI_PREFIX, methods=['GET'])
+ def list_mac_table(self, req, **kwargs):
+ dpid = int(str(kwargs['dpid']))
+ ret = self.simple_switch_app.get_flow_stats(dpid)
+ if ret is None:
+ return Response(status=404)
+
+ return Response(content_type='application/json', body=json.dumps(ret))

$ ryu-manager ryu/app/simple_switch_13.py
Registered VCS backend: git
Registered VCS backend: hg
Registered VCS backend: svn
Registered VCS backend: bzr
loading app ryu/app/simple_switch_13.py
loading app ryu.controller.ofp_handler
loading app ryu.app.ofctl.service
loading app ryu.controller.ofp_handler
creating context wsgi
instantiating app ryu.app.ofctl.service of OfctlService
instantiating app ryu/app/simple_switch_13.py of SimpleSwitch13
instantiating app ryu.controller.ofp_handler of OFPHandler
(10332) wsgi starting up on http://0.0.0.0:8080
...

$ curl -X GET http://localhost:8080/simpleswitch/stats/1 | python -m json.tool
[
{
"OFPFlowStatsReply": {
"body": [
{
"OFPFlowStats": {
"byte_count": 140,
"cookie": 0,
"duration_nsec": 771000000,
"duration_sec": 1,
"flags": 0,
"hard_timeout": 0,
"idle_timeout": 0,
"instructions": [
{
"OFPInstructionActions": {
"actions": [
{
"OFPActionOutput": {
"len": 16,
"max_len": 65535,
"port": 4294967293,
"type": 0
}
}
],
"len": 24,
"type": 4
}
}
],
"length": 80,
"match": {
"OFPMatch": {
"length": 4,
"oxm_fields": [],
"type": 1
}
},
"packet_count": 2,
"priority": 0,
"table_id": 0
}
}
],
"flags": 0,
"type": 1
}
}
]

Thanks,
Iwase

Douglas Harewood-Gill

2017-06-09 12:00:36 UTC

Permalink

Post by Iwase Yusuke
Hi Douglas,
Excuse me for cutting in.
Just for getting flow statistics, how about running your app and ofctl_rest
together as Fujimoto said.
e.g.)
$ ryu-manager your_app.py ryu.app.ofctl_rest
If you want to implement your own REST APIs on your app, Ryu-Book is the
most helpful as far as I know.
(You might already be aware of this though...)
http://osrg.github.io/ryu-book/en/html/rest_api.html
FYI, here is an sample implementation on simple_switch_13.py for getting
flow statistics.
The usage of "WSGI" framework is described on Ryu-Book.
$ git diff
diff --git a/ryu/app/simple_switch_13.py b/ryu/app/simple_switch_13.py
index 3e7c598..f33e474 100644
--- a/ryu/app/simple_switch_13.py
+++ b/ryu/app/simple_switch_13.py
@@ -13,6 +13,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+import json
+
from ryu.base import app_manager
from ryu.controller import ofp_event
from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
@@ -21,14 +23,26 @@ from ryu.ofproto import ofproto_v1_3
from ryu.lib.packet import packet
from ryu.lib.packet import ethernet
from ryu.lib.packet import ether_types
+from ryu.app.ofctl import api as ofctl_api
+from ryu.app.wsgi import ControllerBase
+from ryu.app.wsgi import Response
+from ryu.app.wsgi import route
+from ryu.app.wsgi import WSGIApplication
+
+
+_URI_PREFIX = '/simpleswitch/stats/{dpid}'
OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
+ _CONTEXTS = {'wsgi': WSGIApplication}
super(SimpleSwitch13, self).__init__(*args, **kwargs)
self.mac_to_port = {}
+ wsgi = kwargs['wsgi']
+ wsgi.register(SimpleSwitchController,
+ {SimpleSwitch13.__name__: self})
@set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
out = parser.OFPPacketOut(datapath=datapath,
buffer_id=msg.buffer_id,
in_port=in_port, actions=actions, data=data)
datapath.send_msg(out)
+
+ datapath = ofctl_api.get_datapath(self, dpid)
+ return None
+
+ parser = datapath.ofproto_parser
+ req = parser.OFPFlowStatsRequest(datapath)
+
+ rep = ofctl_api.send_msg(
+ app=self, msg=req,
+ reply_cls=parser.OFPFlowStatsReply, reply_multi=True)
+ return [r.to_jsondict() for r in rep]
+
+
+
+ super(SimpleSwitchController, self).__init__(req, link, data, **config)
+ self.simple_switch_app = data[SimpleSwitch13.__name__]
+
+ dpid = int(str(kwargs['dpid']))
+ ret = self.simple_switch_app.get_flow_stats(dpid)
+ return Response(status=404)
+
+ return Response(content_type='application/json',
body=json.dumps(ret))
$ ryu-manager ryu/app/simple_switch_13.py
Registered VCS backend: git
Registered VCS backend: hg
Registered VCS backend: svn
Registered VCS backend: bzr
loading app ryu/app/simple_switch_13.py
loading app ryu.controller.ofp_handler
loading app ryu.app.ofctl.service
loading app ryu.controller.ofp_handler
creating context wsgi
instantiating app ryu.app.ofctl.service of OfctlService
instantiating app ryu/app/simple_switch_13.py of SimpleSwitch13
instantiating app ryu.controller.ofp_handler of OFPHandler
(10332) wsgi starting up on http://0.0.0.0:8080
...
$ curl -X GET http://localhost:8080/simpleswitch/stats/1 | python -m json.tool
[
{
"OFPFlowStatsReply": {
"body": [
{
"OFPFlowStats": {
"byte_count": 140,
"cookie": 0,
"duration_nsec": 771000000,
"duration_sec": 1,
"flags": 0,
"hard_timeout": 0,
"idle_timeout": 0,
"instructions": [
{
"OFPInstructionActions": {
"actions": [
{
"OFPActionOutput": {
"len": 16,
"max_len": 65535,
"port": 4294967293,
"type": 0
}
}
],
"len": 24,
"type": 4
}
}
],
"length": 80,
"match": {
"OFPMatch": {
"length": 4,
"oxm_fields": [],
"type": 1
}
},
"packet_count": 2,
"priority": 0,
"table_id": 0
}
}
],
"flags": 0,
"type": 1
}
}
]
Thanks,
Iwase

Post by Douglas Harewood-Gill
Hi there. That is fantastic. Sounds exactly like what I am looking for

so thank you.

Post by Douglas Harewood-Gill
One last question for the minute. I know you provided a link but how do

you implement this with custom Ryu controller code?

Post by Douglas Harewood-Gill
My apologies if I am asking something really obvious.
Cheers
Douglas
Hi, Douglas
Ryu has ofctl_rest.py, which is a sample application and provides

REST API to get flow statistics.

Post by Douglas Harewood-Gill
http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html <

http://ryu.readthedocs.io/en/latest/app/ofctl_rest.html>

Post by Douglas Harewood-Gill
I think it is better to use ofctl_rest.py than to implement your own

REST API in your app.

Post by Douglas Harewood-Gill
Thanks,
Fujimoto

Post by Douglas Harewood-Gill
Greetings I am a PhD student new to both Python and Ryu and I was

wondering if anyone could give me some advice.