topology.yml

# Ansible playbook to create a topology diagram from CDP information
# Copyright (C) 2018 Erik Auerswald <auerswal@unix-ag.uni-kl.de>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
---
- name: 'Retrieve CDP neighbor information'
  hosts: OOB
  connection: local
  vars:
    cdp_info_dir: 'cdp_data'
    connectivity_prefix: 'connectivity'
    out_dir: 'graph'
  tasks:
    - name: 'Query devices via OOB interface'
      tags: [ 'get' ]
      ios_command:
        commands: 'show cdp neighbors detail'
      register: cdp
    - name: '+++ DEBUG +++ Print CDP neighbor information'
      tags: [ 'debug_get' ]
      debug: var=cdp
    - name: 'Delete directory for CDP neighbor information'
      tags: [ 'get' ]
      run_once: true
      file:
        path: '{{cdp_info_dir}}'
        state: absent
    - name: 'Create directory for CDP neighbor information'
      tags: [ 'get' ]
      run_once: true
      file:
        path: '{{cdp_info_dir}}'
        state: directory
    - name: 'Write CDP neighbor information to file'
      tags: [ 'get' ]
      copy:
        # the empty line at the end ensures a newline at the end of the last
        # output line (required for POSIX text files)
        content: |
          {{cdp.stdout[0]}}
          {{''}}
        dest: '{{cdp_info_dir}}/{{inventory_hostname}}'
    - name: 'Read CDP neighbor information from file'
      tags: [ 'parse' ]
      set_fact:
        cdp_data: '{{lookup("file", cdp_info_dir + "/" + inventory_hostname)}}'
    - name: '+++ DEBUG +++ Print CDP data read from file'
      tags: [ 'debug_parse' ]
      debug: var=cdp_data
    - name: 'Parse CDP data using TextFSM'
      tags: [ 'parse' ]
      set_fact:
        cdp_neighbors: >
          {{cdp_data |
          parse_cli_textfsm("playbooks/cdp_neighbors_detail.textfsm")}}
    - name: '+++ DEBUG +++ Parse CDP data with TextFSM and print result'
      tags: [ 'debug_parse' ]
      debug: var=cdp_neighbors
    - name: '+++ DEBUG +++ Write Ansible variables to a file'
      tags: [ 'debug_ansible' ]
      run_once: true
      copy:
        content: |
          Module Variables (vars):
          ------------------------
          {{vars | to_nice_yaml}}

          Environment Variables (environment):
          ------------------------------------
          {{environment | to_nice_yaml}}

          Group Names (group_names):
          --------------------------
          {{group_names | to_nice_yaml}}

          Host Variables (hostvars):
          --------------------------
          {{hostvars | to_nice_yaml}}
        dest: './debug-ansible_variables.yml'
    - name: 'Delete directory for graph files'
      tags: [ 'graph' ]
      run_once: true
      file:
        path: '{{out_dir}}'
        state: absent
    - name: 'Create directory for graph files'
      tags: [ 'graph' ]
      run_once: true
      file:
        path: '{{out_dir}}'
        state: directory
    - name: 'Create DOT language description of topology'
      tags: [ 'graph' ]
      run_once: true
      template:
        src: '{{connectivity_prefix}}.j2'
        dest: '{{out_dir}}/{{connectivity_prefix}}.gv'
    - name: 'Render PNG image from DOT language topology description'
      tags: [ 'graph' ]
      run_once: true
      command: >
        dot -Tpng -o{{out_dir}}/{{connectivity_prefix}}.png
                    {{out_dir}}/{{connectivity_prefix}}.gv

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