"Pay it Forward" technology blog

This is my vermiculture bin. It is made from junk and free stuff. I got the Red Wiggler worms from a friend.

This is the bottom of the bin. I cut the top off a sports drink bottle and kept the valve. I drilled a hole in the bin big enough the screw top to poke through. There are two pieces of scrap 2x4 that hold up a false bottom.

More pictures of the drain valve:

The next layer is a piece of wood with holes drilled through:

To start the bin, I soaked shredded paper in water for 15 minutes, wrung it out, then added it to the bin. I also added a few handfuls of dirt and leaves. I added a handful of Red Wiggler worms. Then I added kitchen scraps. I do not add meat or cooked scraps. I do not add citrus peel any more. I found that the worms don't like them and they attract Black Soldier Flies (BSF). BSF are not so bad as they also make compost. I think BSF look gross and make stinkier compost than the worms make. The worm compost ends up like very damp black soil. BSF make gooier, brown compost. The next pictures are of a mature bin.

I put a piece of plastic over the top to hold in humidity. I also put a piece of fiberglass window screen covering the top of the bin which is not shown.

After a few weeks you can drain out the liquid. I dilute the liquid about 5 to 10 parts water to the liquid and water plants with it.

I wanted to access a Floodlight OpenFlow Controller from RHEL 6.4. This can be done with cURL http://curl.haxx.se/ or Python.

Some cURL commands that worked in my environment are below.

Get features of switch:

$ curl http://9.23.13.143:8080/wm/core/switch/00:01:XX:XX:XX:XX:XX:XX/features/json | python -m json.tool

$ curl http://9.23.13.143:8080/wm/core/switch/all/features/json | python -m json.tool

$ curl http://9.23.13.143:8080/wm/core/switch/all/port/json | python -m json.tool

Push a flow:

$ curl -d '{"switch": "00:01:XX:XX:XX:XX:XX:XX", "name":"flow-mod-1", "cookie":"0", "priority":"32768", "ingress-port":"50","active":"true", "actions":"output=51"}'

Get flows:

$ curl http://9.23.13.143:8080/wm/staticflowpusher/list/00:01:XX:XX:XX:XX:XX:XX/json | python -m json.tool

Delete a flow:

$ curl -X DELETE -d '{"name":"flow-mod-1"}' http://<controller_ip>:8080/wm/staticflowpusher/json

The switch can also be managed using Python without cURL. The following script is cobbled together from various others I found, including https://raw.githubusercontent.com/xsited/sdn/master/python/staticflowpusher.py. My version of the script contains changes from the ones I found around the internet so that it works in my environment.

#!/usr/bin/env python

import httplib
import json

class StaticFlowPusher(object):

def __init__(self, server):
self.server = server

def get(self, path, data):
ret = self.rest_call(path, {}, 'GET')
return json.loads(ret[2])

def set(self, path, data):
ret = self.rest_call(path, data, 'POST')
# return ret[0] == 200

def remove(self, path, data):
ret = self.rest_call(path, data, 'DELETE')
# return ret[0] == 200

def rest_call(self, path, data, action):
headers = {
'Content-type': 'application/json',
'Accept': 'application/json',
}
body = json.dumps(data)
conn = httplib.HTTPConnection(self.server, 8080)
conn.request(action, path, body, headers)
response = conn.getresponse()
ret = (response.status, response.reason, response.read())
print ret
conn.close()
return ret

flow1 = {
'switch':"00:01:XX:XX:XX:XX:XX:XX",
"name":"flow-mod-1",
"cookie":"0",
"priority":"32750",
"in_port":"51",
"active":"true"
}

flow3 = {
'switch':"00:01:XX:XX:XX:XX:XX:XX",
"name":"flow-mod-3",
"cookie":"0",
"priority":"32751",
"actions":"output=51",
# "instruction_write_actions":"
# "table":"0x27",
# "ingress-port":"51",
"in_port":"50",
# "eth_vlan_vid":"0x1002",
# "ip_proto":"0x06",
# "output":"51",
# "eth_dst":"00:01:FF:DD:EE:AA:CC:F3",
# "eth_src":"00:01:AA:BB:CC:DD:EE:F1",
# "tp_src":"0x0CBD",
# "tp_dst":"0x0CBE",
# "ipv4_src":"9.1.2.3/24",
# "eth_type":"0x8100",
# "eth-vlan-pcp":"0x3",
# "eth_type":"0x810",
# "eth_vlan_pcp":"0x3",
# "set_vlan_vid":"1002",
# "set_vlan_pcp":"0x4",
# "set_eth_src":"00:01:22:33:44:55:66:F4",
"active":"true"
}

flow4 = {
'switch':"00:01:XX:XX:XX:XX:XX:XX",
"name":"flow-mod-4",
"cookie":"0",
"priority":"32751",
"actions":"output=51",
"in_port":"50",
"active":"true"
}

flow5 = {
'switch':"00:01:XX:XX:XX:XX:XX:XX",
"name":"flow-mod-5",
"cookie":"0",
"priority":"32751",
"actions":"output=50",
"in_port":"51",
"active":"true"
}

switch01 = {
'switch':"00:01:XX:XX:XX:XX:XX:XX"
}

switchpath = '00:01:XX:XX:XX:XX:XX:XX'
pushflowpath = '/wm/staticflowpusher/json'
#getflowpath = '/wm/staticflowpusher/list/00:01:XX:XX:XX:XX:XX:XX/json'
getflowpath = '/wm/staticflowpusher/list/'+switchpath+'/json'
getallflowpath = '/wm/staticflowpusher/list/all/json'
pusher = StaticFlowPusher('127.0.0.1')
print 'pushing flowpath 4'
pusher.set(pushflowpath, flow4)
print 'pushing flowpath 5'
pusher.set(pushflowpath, flow5)
#print 'pushing flowpath 1'
#pusher.set(pushflowpath, flow1)
print 'getting flowpath'
pusher.get(getflowpath, switch01)
print 'getting all flowpaths'
pusher.get(getallflowpath, switch01)
#print 'removing flowpath'
#pusher.remove(pushflowpath, {"name": "flow-mod-3"})
print 'getting flowpath'
pusher.get(getflowpath, switch01)

Links to related information:

Floodlight and Python documentation.

http://www.openflowhub.org/display/floodlightcontroller/Floodlight+REST+API

http://www.openflowhub.org/display/floodlightcontroller/Static+Flow+Pusher+API+%28New%29

https://raw.githubusercontent.com/xsited/sdn/master/python/staticflowpusher.py

Versions:

Python 2.6.6

Linux 2.6.39-400.17.1.el6uek.x86_64

Floodlight v1.0.
OpenFlow 1.0 switch.

"Pay it Forward" technology blog

Wednesday, April 22, 2015

North Shore Line

Saturday, March 28, 2015

Vermiculture

Thursday, March 19, 2015

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Accessing Floodlight with cURL and Python