Red Hat Ansible for Network Automation

Add group variables for domain name and name servers. The host name is automatically available by virtue of the inventory_hostname variable.

Add a domain_name variable and a name_servers variable to the network group.

[student@workstation ansible-generic-project]$ cat group_vars/network/vars.yml
ansible_connection: network_cli
domain_name: lab.example.com
name_servers:
- 8.8.8.8
- 8.8.4.4

Create two Jinja2 templates that convert data into commands: one for VyOS devices and one for IOS devices. Name them vyos-hn-dn-ns.j2 and ios-hn-dn-ns.j2, respectively.

1. If it does not already exist, create a j2 directory to hold Jinja2 template files.

   [student@workstation ansible-generic-project]$ mkdir j2

2. Create a Jinja2 template named j2/vyos-hn-dn-ns.j2 that generates host name, domain name and nameserver configuration statements for VyOS systems.

   [student@workstation ansible-generic-project]$ cat j2/vyos-hn-dn-ns.j2
   set system host-name {{ inventory_hostname }}
   set system domain-name {{ domain_name }}
   {% for ns in name_servers %}
   set system name-server {{ ns }}
   {% endfor %}

3. Create a Jinja2 template named j2/ios-hn-dn-ns.j2 that generates domain name and nameserver configuration statements for IOS systems.

   [student@workstation ansible-generic-project]$ cat j2/ios-hn-dn-ns.j2
   hostname {{ inventory_hostname }}
   ip domain name {{ domain_name }}
   {% for ns in name_servers %}
   ip name-server {{ ns }}
   {% endfor %}

Create two playbooks named j2test-vyos-hn-dn-ns.yml and j2test-ios-hn-dn-ns.yml. The connection method should be set to local in these playbooks. Each of the playbooks should contain a play consisting of a single task, which uses the template module to simply write to a file or series of files (one per inventory_hostname) the document produced by the corresponding template. Use these playbooks to verify that the templates do indeed generate the desired commands.

1. Create a directory to hold files your playbooks create.

   [student@workstation ansible-generic-project]$ mkdir out

2. Create the j2test-vyos-hn-dn-ns.yml playbook that generates VyOS configuration statements for a representative VyOS device and writes them to a file.

   [student@workstation ansible-generic-project]$ cat j2test-vyos-hn-dn-ns.yml
   ---
   - name: generate VyOS hostname, domain name, and nameserver statements
     hosts: spine01
     connection: local
     vars:
       tmpl: j2/vyos-hn-dn-ns.j2
       outfile: out/vyos-hn-dn-ns-{{ inventory_hostname }}.cmd
   
     tasks:
   
     - name: read from template, write to output file
       template:
         src:  "{{ tmpl }}"
         dest: "{{ outfile }}"

3. Perform the play in the j2test-vyos-hn-dn-ns.yml playbook.

   [student@workstation ansible-generic-project]$ ansible-playbook \
   > j2test-vyos-hn-dn-ns.yml

4. Confirm that it generates VyOS configuration statements as desired.

   [student@workstation ansible-generic-project]$ cat out/vyos-hn-dn-ns-spine01.cmd
   set system host-name spine01
   set system domain-name lab.example.com
   set system name-server 8.8.8.8
   set system name-server 8.8.4.4

5. Create the j2test-ios-hn-dn-ns.yml playbook that generates IOS configuration statements for a representative IOS device and writes them to a file.

   [student@workstation ansible-generic-project]$ cat j2test-ios-hn-dn-ns.yml
   ---
   - name: generate ios hostname, domain name, and nameserver statements
     hosts: cs01
     connection: local
     vars:
       tmpl: j2/ios-hn-dn-ns.j2
       outfile: out/ios-hn-dn-ns-{{ inventory_hostname }}.cmd
   
     tasks:
   
     - name: read from template, write to output file
       template:
         src:  "{{ tmpl }}"
         dest: "{{ outfile }}"

6. Perform the play in the j2test-ios-hn-dn-ns.yml playbook.

   [student@workstation ansible-generic-project]$ ansible-playbook \
   > j2test-ios-hn-dn-ns.yml

7. Confirm that it generates IOS configuration statements as desired.

   [student@workstation ansible-generic-project]$ cat out/ios-hn-dn-ns-cs01.cmd
   set system host-name cs01
   set system domain-name lab.example.com
   set system name-server 8.8.8.8
   set system name-server 8.8.4.4

Create a playbook named set-hn-dn-ns.yml that sets host name, domain name, and nameservers for networking devices by sourcing configuration statements directly from an appropriate Jinja2 template. The template should be selected according to the value of the ansible_network_os variable.

Create a multivendor playbook named set-hn-dn-ns.yml that uses the when conditional to perform or skip tasks based on the value of the ansible_network_os variable. The connection method for these should be network_cli, NOT local. The playbook consists of a play that sets host name, domain name, and nameservers for both VyOS and IOS devices:

[student@workstation ansible-generic-project]$ cat set-hn-dn-ns.yml
---
- name: configure hostname, domain name, and nameserver
  hosts: network
  vars:
    tmpl: j2/{{ ansible_network_os }}-hn-dn-ns.j2

  tasks:

  - name: read from template, configure IOS device
    ios_config:
      src:  "{{ tmpl }}"
    when: ansible_network_os == 'ios'

  - name: read from template, configure VyOS device
    vyos_config:
      src:  "{{ tmpl }}"
    when: ansible_network_os == 'vyos'

Perform the play in the set-hn-dn-ns.yml playbook, limiting it to a single target.

[student@workstation ansible-generic-project]$ ansible-playbook -l spine01 \
> set-hn-dn-ns.yml

Compose a playbook named ios-vyos-assert-domain.yml that asserts that the domain name is currently set to"lab.example.com".

[student@workstation ansible-generic-project]$ cat ios-vyos-assert-domain.yml
---
- name: multi-vendor play that asserts value of domain name
  hosts: network
  vars:
    correct_domain: lab.example.com
    ios_command: sh run | include domain
    vyos_command: sh conf comm | grep domain-name

  tasks:

  - name: "{{ ios_command }} on IOS device"
    ios_command:
      commands:
      - "{{ ios_command }}"
    register: ios_result
    when: ansible_network_os == 'ios'

  - name: "assert IOS device is in {{ correct_domain }}"
    assert:
      that: "'{{ correct_domain }}' in ios_result.stdout[0]"
    when: ansible_network_os == 'ios'

  - name: "{{ vyos_command }} on VyOS device"
    vyos_command:
      commands:
      - "{{ vyos_command }}"
    register: vyos_result
    when: ansible_network_os == 'vyos'

  - name: "assert VyOS device is in {{ correct_domain }}"
    assert:
      that: "'{{ correct_domain }}' in vyos_result.stdout[0]"
    when: ansible_network_os == 'vyos'

Perform the play you created that asserts the value of the domain name.

[student@workstation ansible-generic-project]$ ansible-playbook \
> ios-vyos-assert-domain.yml

Commit your work to the Git repository. If prompted for credentials, user and password are student and student.

[student@workstation ansible-generic-project]$ git add -A :/ && git commit -m \
> "ch7 lab3" && git push