I have a big issue that I can not understand. I have two programs, one with Java 17 using Spring Boot 3.1.2 and the other using Python 2.7 on Ubuntu 14.04, and the VM is working on VMware. Unfortunately, I can not change the Python and the Ubuntu, so I must work with them. My main problem is stability. I am trying to understand why one day it was working perfectly, and the other day I had a lot of issues.
I am using Miniet for the first machine that has the issue, and for the other machine for the controller, I am using Opendaylight.
I will start with the Java code and then with the Python code.
The Java program:
Write Topology class:
public class Write_Topology {
public String write_topology(HashMap<Integer,Node> nodes,
String Topology_name ){
ObjectMapper mapper = new ObjectMapper();
// Path path = Paths.get(System.getProperty("userhome"), "api", Topology_name + ".json");
// String path = System.getProperty("userhome") + "/api/" + Topology_name + ".json";
String path = "/home/mininet/api/" + Topology_name + ".json";
try {
File file = new File(path);
FileWriter fileWriter = new FileWriter(path);
fileWriter.write(mapper.writeValueAsString(nodes));
fileWriter.close();
} catch (IOException e) {
throw new RuntimeException(e);
}
return path;
}
}
The service class:
@Service
public class Create_Topology_Service {
private final Create_Topology create_topology = new Create_Topology();
private final Check_host_range checkHostRange = new Check_host_range();
private final Write_Topology writeTopology = new Write_Topology();
public Optional create_topology_service_method(Create_Topology_Model createTopologyModel){
HashMap<Integer,Node> nodes;
try {
if(checkHostRange.check_host_range_method(
createTopologyModel.ipBase,
createTopologyModel.number_of_hosts_per_switch,
createTopologyModel.number_of_switches
)) {
nodes = create_topology
.create_topology(createTopologyModel.number_of_switches,
createTopologyModel.number_of_hosts_per_switch);
String path = writeTopology.write_topology(nodes, createTopologyModel.topology_name);
String[] cmd = getStrings(createTopologyModel,path);
IndexController.process = Runtime.getRuntime().exec(cmd);
System.out.println(IndexController.process.pid());
Read_Output read_output = new Read_Output();
read_output.read_output();
}else{
return Optional.of(getResponse());
}
}catch (Exception e){
throw new RuntimeException(e);
}
return Optional.of(nodes);
}
private String[] getStrings(Create_Topology_Model createTopologyModel, String path) {
if(createTopologyModel.controller_port!=0) {
String command = "nohup sudo python ~/api/API_TEST.py " +
path +
" " +
createTopologyModel.ipBase +
" " +
createTopologyModel.controller_ip +
" " +
createTopologyModel.controller_port +
" " +
createTopologyModel.switches_name_prefix +
" " +
createTopologyModel.hosts_name_prefix +
" " +
createTopologyModel.number_of_switches +
" " +
createTopologyModel.number_of_hosts_per_switch +
" " +
"&";
System.out.println(command);
return new String[]{"/bin/bash", "-c", command};
}
String command = "nohup sudo python ~/api/API_TEST.py " +
path +
" " +
createTopologyModel.ipBase +
" " +
createTopologyModel.controller_ip +
" " +
6633 +
createTopologyModel.switches_name_prefix +
" " +
createTopologyModel.hosts_name_prefix +
" " +
createTopologyModel.number_of_switches +
" " +
createTopologyModel.number_of_hosts_per_switch +
" " +
"&";
System.out.println(command);
return new String[]{"/bin/bash", "-c", command};
}
private List<String> getResponse(){
List<String> response = new ArrayList<>();
response.add("Too many hosts the specified base Ip");
response.add("1) You can reduce number of hosts per device");
response.add("2) You can increase the number of hosts in the network");
return response;
}
}
The endpoint:
@PostMapping(path = {"CreateTopology"})
public Optional create_topology(@RequestBody Create_Topology_Model createTopologyModel) {
return this.createTopologyService.create_topology_service_method(createTopologyModel);
}
The python code:
The main file:
#!/bin/python
import sys
import json
from Create_Topology2 import Create_Topology
if __name__ == '__main__':
print(sys.argv[1])
print(sys.argv[2],
sys.argv[3],
int(sys.argv[4]),
sys.argv[5],
sys.argv[6])
with open(sys.argv[1], 'r') as f:
data = json.load(f)
print("2: ",sys.argv[2],
"3: ",sys.argv[3],
"4: ",int(sys.argv[4]),
"5: ",sys.argv[5],
"6: ",sys.argv[6],
"data: ",data)
topology = Create_Topology(sys.argv[2],
sys.argv[3],
int(sys.argv[4]),
sys.argv[5],
sys.argv[6],
data)
topology.create_topology()
The Create_Topology:
#!/bin/python
from mininet.net import Mininet
from mininet.node import Controller, RemoteController, OVSController
from mininet.node import CPULimitedHost, Host, Node
from mininet.node import OVSKernelSwitch, UserSwitch
from mininet.node import IVSSwitch
from mininet.cli import CLI
from mininet.log import setLogLevel, info
from mininet.link import TCLink, Intf
from Random_nodes_service import random_nodes_service
class Create_Topology():
def __init__(self,
ipBase,
controller_ip,
controller_port,
switches_name_prefix,
hosts_name_prefix,
topology
):
self.ipBase = ipBase
self.controller_ip = controller_ip
self.controller_port = controller_port
self.switches_name_prefix = switches_name_prefix
self.hosts_name_prefix = hosts_name_prefix
self.topology = topology
self.copy_ipBase = ipBase
self.host_number=0
def get_host(self):
ip = self.copy_ipBase.split('/')[0]
a = ip.split('.')
if 254 < (int(a[3]) + 1):
if 254 < (int(a[2])+1):
c = int(a[2]) +1
host_ip = ""
for b in range(0,1):
host_ip += a[b]+"."
host_ip += str(c) + "." + "0"+"."+"1"
self.copy_ipBase = host_ip
return host_ip
else:
c = int(a[2]) +1
host_ip = ""
for b in range(0,2):
host_ip += a[b]+"."
host_ip += str(c) + "." + "1"
self.copy_ipBase = host_ip
return host_ip
c = int(a[3]) +1
host_ip = ""
for b in range(0,3):
host_ip += a[b]+"."
host_ip += str(c)
self.copy_ipBase = host_ip
return host_ip
def create_topology(self):
net = Mininet(topo=None,
build=False,
ipBase=self.ipBase)
c0 = net.addController(name='c0',
controller=RemoteController,
ip=self.controller_ip, # variable that I will pass in the
protocol='tcp',
port=self.controller_port) # vatiable with the default value of 6633
switches_list = []
for i in self.topology:
print(i)
switches_list.append(net.addSwitch((self.switches_name_prefix+str(i)),
cls=OVSKernelSwitch))
print(switches_list)
a=0
for i in self.topology:
for j in range(self.topology[i]["hosts"]):
net.addLink(switches_list[int(i)],
net.addHost(
self.hosts_name_prefix+str(a+j),
cls=Host,
ip=self.get_host(),
defaultRoute=None))
a=a+1
for j in self.topology[i]["list"]:
net.addLink(switches_list[int(i)],switches_list[int(j)])
info( '*** Starting network\n')
net.build()
info( '*** Starting controllers\n')
for controller in net.controllers:
controller.start()
info( '*** Starting switches\n')
for i in switches_list:
net.get(str(i)).start([c0])
info( '*** Post configure switches and hosts\n')
CLI(net)
net.stop()
Now let me explain a bit the flow:
The Java code will get a request with the details and create the topology. It will write it on a JSON file, pass everything in a command line to the Python script, and do the work of the program I want to run in the background.
The output is:
nohup sudo python ~/api/API_TEST.py /home/mininet/api/topology3.json 10.0.0.0/8 192.168.241.129 6633 sw h 10 10 &
nohup sudo python ~/api/API_TEST.py /home/mininet/api/topology3.json 10.0.0.0/8 192.168.241.129 6633 sw h 10 10 &
nohup sudo python ~/api/API_TEST.py /home/mininet/api/topology3.json 10.0.0.0/8 192.168.241.129 6633 sw h 10 10 &
/home/mininet/api/topology3.json
('10.0.0.0/8', '192.168.241.129', 6633, 'sw', 'h')
('2: ', '10.0.0.0/8', '3: ', '192.168.241.129', '4: ', 6633, '5: ', 'sw', '6: ', 'h', 'data: ', {u'1': {u'hosts': 3, u'list': [3, 4, 6, 7, 8, 9]}, u'0': {u'hosts': 3, u'list': [1, 3, 4, 5, 6, 7, 9]}, u'3': {u'hosts': 8, u'list': [4, 5, 6, 7, 8, 9]}, u'2': {u'hosts': 4, u'list': [3, 5, 6, 8, 9]}, u'5': {u'hosts': 8, u'list': [6, 7, 8]}, u'4': {u'hosts': 4, u'list': [5, 7]}, u'7': {u'hosts': 2, u'list': [8]}, u'6': {u'hosts': 7, u'list': [7, 8]}, u'9': {u'hosts': 0, u'list': []}, u'8': {u'hosts': 9, u'list': [9]}})
1
0
3
2
5
4
7
6
9
8
[<OVSSwitch sw1: lo:127.0.0.1 pid=9709> , <OVSSwitch sw0: lo:127.0.0.1 pid=9712> , <OVSSwitch sw3: lo:127.0.0.1 pid=9715> , <OVSSwitch sw2: lo:127.0.0.1 pid=9718> , <OVSSwitch sw5: lo:127.0.0.1 pid=9721> , <OVSSwitch sw4: lo:127.0.0.1 pid=9724> , <OVSSwitch sw7: lo:127.0.0.1 pid=9727> , <OVSSwitch sw6: lo:127.0.0.1 pid=9730> , <OVSSwitch sw9: lo:127.0.0.1 pid=9733> , <OVSSwitch sw8: lo:127.0.0.1 pid=9736> ]
mininet>
In this case opendaylight is not showing anything, as you can see in the next picture:
If I will put the same command to call directly the python script:
sudo python ~/api/API_TEST.py /home/mininet/api/topology3.json 10.0.0.0/8 192.168.241.129 6633 sw h 10 10
I will get the right output:
Moreover, when I am running the scrip with the nohup:
nohup sudo python ~/api/API_TEST.py /home/mininet/api/topology3.json 10.0.0.0/8 192.168.241.129 6633 sw h 10 10 &
I will get the right output:
The error in the opendaylight is:
Exception in thread "Thread-421" java.lang.IllegalStateException: Expected state: HANDSHAKING, actual state:RIP
at org.opendaylight.openflowplugin.openflow.md.core.ConnectionConductorImpl.checkState(ConnectionConductorImpl.java:386)
at org.opendaylight.openflowplugin.openflow.md.core.ConnectionConductorImpl.onConnectionReady(ConnectionConductorImpl.java:448)
at org.opendaylight.openflowjava.protocol.impl.core.connection.ConnectionAdapterImpl$1.run(ConnectionAdapterImpl.java:185)
at java.lang.Thread.run(Thread.java:750)
At this point, I am still trying to figure out what I should do more; if you have any suggestions, please feel free to comment on them.