netdiff 0.3.1

Calculates a diff of a network topology

---

Netdiff is an experimental Python library that provides utilities for parsing network topologies of open source dynamic routing protocols and calculating changes in these topologies.

It was developed to abstract the differences between the different JSON structures of the open source dynamic routing protocols (like OLSR and batman-advanced).

Install stable version from pypi

Install from pypi:

pip install netdiff

Install development version

Install tarball:

pip install https://github.com/ninuxorg/netdiff/tarball/master

Alternatively you can install via pip using git:

pip install -e git+git://github.com/ninuxorg/netdiff#egg=netdiff

If you want to contribute, install your cloned fork:

git clone [e-mail]:<your_fork>/netdiff.git
cd netdiff
python setup.py develop

Basic Usage Example

Calculate diff of an OLSR 0.6.x topology:

from netdiff import OlsrParser
from netdiff import diff

stored = OlsrParser('./stored-olsr.json')
latest = OlsrParser('telnet://127.0.0.1:9090')
diff(stored, latest)

The output will be a dictionary with the following structure:

{
    "added": []
    "removed": []
}

In alternative, you can use the subtraction operator:

from netdiff import OlsrParser
from netdiff import diff

stored = OlsrParser('./stored-olsr.json')
latest = OlsrParser('telnet://127.0.0.1:9090')
latest - stored

Parsers

Parsers are classes that extend netdiff.base.BaseParser and implement a parse method which is in charge of converting a python data structure into networkx.Graph object.

Parsers also have a json method which returns valid NetJSON output.

The available parsers are:

• netdiff.OlsrParser: parser for the olsrd jsoninfo plugin

• netdiff.BatmanParser: parser for the batman-advanced alfred tool

• netdiff.Bmx6Parser: parser for the BMX6 b6m tool

• netdiff.CnmlParser: parser for CNML 0.1

• netdiff.NetJsonParser: parser for the NetworkGraph NetJSON object.

Parsers must be initialized with a string which can represent one of the following:

• path to JSON file

• HTTP url to JSON file

• telnet url to JSON file

• JSON formatted string

• python dictionary representing a JSON structure

Local file example:

from netdiff import BatmanParser
BatmanParser('./my-stored-topology.json')

HTTP example:

from netdiff import NetJsonParser
url = 'https://raw.githubusercontent.com/interop-dev/json-for-networks/master/examples/network-graph.json'
NetJsonParser(url)

NetJSON output

Netdiff parsers can return a valid NetJSON NetworkGraph object:

from netdiff import OlsrParser

olsr = OlsrParser('telnet://127.0.0.1:9090')

# will return a dict
olsr.json(dict=True)

# will return a JSON formatted string
print(olsr.json(indent=4))

Output:

{
    "type": "NetworkGraph",
    "protocol": "OLSR",
    "version": "0.6.6",
    "revision": "5031a799fcbe17f61d57e387bc3806de",
    "metric": "ETX",
    "nodes": [
        {
            "id": "10.150.0.3"
        },
        {
            "id": "10.150.0.2"
        },
        {
            "id": "10.150.0.4"
        }
    ],
    "links": [
        {
            "source": "10.150.0.3",
            "target": "10.150.0.2",
            "weight": 2.4
        },
        {
            "source": "10.150.0.3",
            "target": "10.150.0.4",
            "weight": 1.0
        }
    ]
}

Running tests

Install your forked repo:

git clone git://github.com/<your_fork>/netdiff
cd netdiff/
python setup.py develop

Install test requirements:

pip install -r requirements-test.txt

Run tests with:

./runtests.py

Alternatively, you can use the nose command (which has a ton of available options):

nosetests
nosetests tests.olsr  # run only olsr related tests
nosetests tests/olsr  # variant form of the previous command
nosetests tests.olsr.tests:TestOlsrParser  # variant form of the previous command
nosetests tests.olsr.tests:TestOlsrParser.test_parse  # run specific test

See test coverage with:

coverage run --source=netdiff runtests.py && coverage report

Contribute

1. Join the ninux-dev mailing list

2. Fork this repo and install it

3. Follow PEP8, Style Guide for Python Code

4. Write code

5. Write tests for your code

6. Ensure all tests pass

7. Ensure test coverage is not under 90%

8. Document your changes

9. Send pull request