draw_topology_graphviz.py

# Based on http://matthiaseisen.com/articles/graphviz/

import graphviz as gv


styles = {
    'graph': {
        'label': 'Network Map',
        'fontsize': '16',
        'fontcolor': 'white',
        'bgcolor': '#333333',
        'rankdir': 'BT',
    },
    'nodes': {
        'fontname': 'Helvetica',
        'shape': 'box',
        'fontcolor': 'white',
        'color': '#006699',
        'style': 'filled',
        'fillcolor': '#006699',
        'margin': '0.4',
    },
    'edges': {
        'style': 'dashed',
        'color': 'green',
        'arrowhead': 'open',
        'fontname': 'Courier',
        'fontsize': '14',
        'fontcolor': 'white',
    }
}


def apply_styles(graph, styles):
    graph.graph_attr.update(
        ('graph' in styles and styles['graph']) or {}
    )
    graph.node_attr.update(
        ('nodes' in styles and styles['nodes']) or {}
    )
    graph.edge_attr.update(
        ('edges' in styles and styles['edges']) or {}
    )
    return graph


def draw_topology(topology_dict, output_filename='img/topology'):
    nodes = set([key[0] for key in topology_dict.keys() + topology_dict.values()])

    g1 = gv.Graph(format='svg')

    for node in nodes:
        g1.node(node)

    for key, value in topology_dict.iteritems():
        head, t_label = key
        tail, h_label = value
        g1.edge(head, tail, headlabel=h_label, taillabel=t_label, label=" "*12)
        # headport='nw' tailport='s'
    g1 = apply_styles(g1, styles)

    print(g1.source)
    filename = g1.render(filename=output_filename)
    print "Graph saved in", filename

diag5 = {('R3', 'Fa0/1'): ('R1', 'Fa0/1'),
         ('R2', 'Fa3/0'): ('R1', 'Fa3/0'),
         ('R2', 'Fa1/0'): ('R1', 'Fa0/1'),
         ('R4', 'Fa4/0'): ('R1', 'Fa4/0'),
         ('R2', 'Fa0/0'): ('R3', 'Fa0/0'),
         ('R5', 'Fa4/0'): ('R3', 'Fa3/0'),
         ('R4', 'Fa1/0'): ('R3', 'Fa0/0'),
         ('R4', 'Fa1/0'): ('R2', 'Fa1/0'),
         ('R4', 'Fa0/1'): ('R5', 'Fa0/1')}

draw_topology(diag5)

img/topology.svg: