Ansible: Template Engine nutzen um Cisco Konfigurationen zu erzeugen

Ansible verwendet als Template Engine Jinja2. Als Beispiel wird für einen Switch die Radius Konfiguration erzeugt.
Man kann direkt vom Template aus die Konfiguration auf ein Gerät fallen lassen oder so wie in diesem Fall einfach als File speichern.

Eine ausführliche Anleitung was man alles mit der Jinja2 Template Engine machen kann ist unter http://jinja.pocoo.org/docs/2.10/ zu finden.

Template radius_demo.j2:

{% for rad in globals_demo.aaagroup %}
aaa group server radius {{ rad.name }}
{% for server in rad.server %}
 server name {{ server }}
{% endfor %}
 deadtime {{ rad.deadtime }}

{% endfor %}

{% for server in globals_demo.radiusserver %}
radius server {{ server.name }}
 address ipv4 {{ server.address }} auth-port {{ server.authport }} acct-port {{ server.acctport }}
 timeout {{ server.timeout }}
 retransmit {{ server.retransmit }}
 key {{ server.pskkey }}

{% endfor %}

globals_demo.yaml – Konfigdatei mit globalen Variablen welche in das Playbook geladen werden.

---

aaagroup:
  - name: DOT1X
    server:
      - RADIUS1-DOT1X
      - RADIUS2-DOT1X
      - RADIUS3-DOT1X
      - RADIUS4-DOT1X
    deadtime: 1
    
radiusserver:
  - name: RADIUS1-DOT1X
    address: 192.168.1.101
    authport: 1812
    acctport: 1813
    timeout: 4
    retransmit: 3
    pskkey: 7 02000B5409071D

  - name: RADIUS2-DOT1X
    address: 192.168.1.102
    authport: 1812
    acctport: 1813
    timeout: 4
    retransmit: 3
    pskkey: 7 02000B5409071D

  - name: RADIUS3-DOT1X
    address: 192.168.1.103
    authport: 1812
    acctport: 1813
    timeout: 4
    retransmit: 3
    pskkey: 7 02000B5409071D

  - name: RADIUS4-DOT1X
    address: 192.168.1.104
    authport: 1812
    acctport: 1813
    timeout: 4
    retransmit: 3
    pskkey: 7 02000B5409071D

config_gen.yaml – Das Playbook welches die Konfiguration erzeugen soll

---
- hosts: all
  connection: local
  gather_facts: False
  vars:
    cli:
      host: "{{ inventory_hostname }}"
      username: "{{ ansible_user }}"
      password: "{{ ansible_ssh_pass }}"

  tasks:
  - name: Load globals
    include_vars:
      file: globals_demo.yaml
      name: globals_demo

  - name: Generate config
    template:
      src: radius_demo.j2
      dest: "/tmp/out_{{ inventory_hostname }}.cfg"

Testlauf config_gen.yaml Playbook

ansible-playbook -i demo.ini config_gen.yaml -v

PLAY [all] *****************************************************************

TASK [Load globals] ********************************************************
ok: [switch1] => {"ansible_facts": {"globals_demo": {"aaagroup": [{"deadtime": 1, "name": "DOT1X", "server": ["RADIUS1-DOT1X", "RADIUS2-DOT1X", "RADIUS3-DOT1X", "RADIUS4-DOT1X"]}], "radiusserver": [{"acctport": 1813, "address": "192.168.1.101", "authport": 1812, "name": "RADIUS1-DOT1X", "pskkey": "7 02000B5409071D", "retransmit": 3, "timeout": 4}, {"acctport": 1813, "address": "192.168.1.102", "authport": 1812, "name": "RADIUS2-DOT1X", "pskkey": "7 02000B5409071D", "retransmit": 3, "timeout": 4}, {"acctport": 1813, "address": "192.168.1.103", "authport": 1812, "name": "RADIUS3-DOT1X", "pskkey": "7 02000B5409071D", "retransmit": 3, "timeout": 4}, {"acctport": 1813, "address": "192.168.1.104", "authport": 1812, "name": "RADIUS4-DOT1X", "pskkey": "7 02000B5409071D", "retransmit": 3, "timeout": 4}]}}, "ansible_included_var_files": ["/home/ansible/_ansible_cisco_tests/globals_demo.yaml"], "changed": false}

TASK [Generate config] *****************************************************
ok: [switch1] => {"changed": false, "checksum": "b1cac79a0ba981ab398439a9102df687b7932ede", "gid": 1001, "group": "ansible", "mode": "0644", "owner": "ansible", "path": "/tmp/out_switch1.cfg", "size": 715, "state": "file", "uid": 1001}

PLAY RECAP *****************************************************************
switch1                : ok=2    changed=0    unreachable=0    failed=0   

Ausgabe out_switch1.cfg

aaa group server radius DOT1X
 server name RADIUS1-DOT1X
 server name RADIUS2-DOT1X
 server name RADIUS3-DOT1X
 server name RADIUS4-DOT1X
 deadtime 1


radius server RADIUS1-DOT1X
 address ipv4 192.168.1.101 auth-port 1812 acct-port 1813
 timeout 4
 retransmit 3
 key 7 02000B5409071D

radius server RADIUS2-DOT1X
 address ipv4 192.168.1.102 auth-port 1812 acct-port 1813
 timeout 4
 retransmit 3
 key 7 02000B5409071D

radius server RADIUS3-DOT1X
 address ipv4 192.168.1.103 auth-port 1812 acct-port 1813
 timeout 4
 retransmit 3
 key 7 02000B5409071D

radius server RADIUS4-DOT1X
 address ipv4 192.168.1.104 auth-port 1812 acct-port 1813
 timeout 4
 retransmit 3
 key 7 02000B5409071D

Möchte man die Konfig direkt auf ein Gerät ausrollen kann man das Playbook wie folgt erweitern:

- name: Apply RADIUS configuration to switch
  ios_config:
    src: radius_demo.j2
    provider: "{{ cli }}"
    match: line