pyns2

pyns2(renamed from netns-siml) is network simulator with linux network namespace create virtual network by yaml format config file.

Blog post(Japanese)

support

interface type

Now veth and bridge type interface is supported.

environment

This tool works on Linux and need root access.
To quick use, please you can use Vagrant.
This also works on privileged docker container. But under docker for mac environment, external access(NAT) don’t work.

quick start

You can try pyns2 in two ways.

Vagrant

If you try pyns2 with vagrant, you can use full function; an external network access and ebpf monitoring.

clone this repository

$ git clone https://github.com/terassyi/pyns2.git
$ cd pyns2

run vm and connect it
```
$ vagrant up
$ vagrant ssh
```

run example

$ pyns2 run pyns2/example/example-container.yml

Docker

You can try pyns2 with docker easier than with vagrant, but features are limited.

clone this repository

$ git clone https://github.com/terassyi/pyns2.git
$ cd pyns2

run container

$ docker build -t pyns2 .
$ docker run -it --privileged --name pyns2 bash

run example
```
$ pyns2 run pyns2/example/example.yml
```

example

This is the example of network definition. This file is in examples/example-container.yml

example-network-container:
    host:
        ifaces:
            br0:
                type: "bridge"
                address: "192.168.50.2/24"
                ifaces:
                    - "host1-veth1-br"
                    - "host2-veth1-br"
                    - "host-veth1-br"
            host-veth1:
                type: "veth"
                address: "192.168.50.1/24"
                peer: "host-veth1-br"
        nat:
          src: "192.168.50.0/24"
          out_iface: "eth0"
    netns:
        host1:
            ifaces:
                host1-veth1:
                    type: "veth"
                    address: "192.168.50.100/24"
                    peer: "host1-veth1-br"
            routes:
              - route:
                    gateway: "192.168.50.1"
                    dest: "default"
        host2:
            ifaces:
                host2-veth1:
                    type: "veth"
                    address: "192.168.50.101/24"
                    peer: "host2-veth1-br"
            routes:
                - route:
                    gateway: "192.168.50.1"
                    dest: "default"

Other exampele is located in examples/

format

command

create <file>

This command create netns and interface.
set <file>

This command set created interfaces in netns
run <file>

This command run virtual network from config file. This command is equal to create and set
delete <file>

This command deletes virtual network created by run command
exec <netns name> <command>
This command executes the command(default is bash) in the target network namespace.

Note: if you want to execute the command contains space(exp: ping 8.8.8.8) , you have to write as list object like [‘ping’, ‘8.8.8.8’]
up <file>

This command up created interfaces
down <file>

This command down creted interfaces
list <file>

This command shows created netns
validate <file>

This command checks whether config file valid
check_netns

This command output current netns name

Future work

implement monitoring modules
add supports of other interface types