Introduction

When rolling out network configs I kept address assignments in spreadsheets because they are easy to edit. Translating those tables into Ansible host vars manually grew painful, so this plugin lets each CSV row feed host-specific variables automatically. During template rendering every device pulls its unique addresses from the sheet, keeping the workflow spreadsheet-friendly while delivering correct per-host values in playbooks.

Requirements

Parse data from CSV into host variables.

CSV file example:

hostname,gateway,vlan30,vlan40,vlan50,vlan60,vlan70
localhost,192.168.30.254,192.168.30.31,192.168.40.31,192.168.50.31,192.168.60.31,192.168.70.31
  • Place the CSV file in the csv_vars directory under inventory or playbook, and it will be automatically parsed.
  • The hostname field in the CSV must match the host name in the inventory.
  • It is recommended to name the CSV as GROUP_OR_HOST_NAME.csv. Multiple CSV files are supported, and variable overriding is also supported.

Write the Plugin

File path: vars_plugins/csv_vars.py

1

...existing code...

Code from https://github.com/guozijn/csv_vars

CSV File

Place the CSV file in the csv_vars directory under inventory or playbook.

1
2
3
4
5

mdkir csv_vars
cat << EOF >> csv_vars/nodes.csv
hostname,gateway,vlan30,vlan40,vlan50,vlan60,vlan70
192.168.77.130,192.168.30.254,192.168.30.31,192.168.40.31,192.168.50.31,192.168.60.31,192.168.70.31
EOF

Run Playbook

1
2
3
4
5
6
7
8
9

# cat test_vars.yml

- hosts: 192.168.77.130
  gather_facts: no
  tasks:
    - debug:
        msg: "{{ lookup('vars', item) }}"
      loop: "{{ hostvars[inventory_hostname].keys() | select('match', '^vlan.*$|gateway') | list }}"

Execution result:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

# ansible-playbook test_vars.yml

PLAY [192.168.77.130] ************************************************************************************************

TASK [debug] *********************************************************************************************************
ok: [192.168.77.130] => (item=gateway) => {
    "msg": "192.168.30.254"
}
ok: [192.168.77.130] => (item=vlan60) => {
    "msg": "192.168.60.31"
}
ok: [192.168.77.130] => (item=vlan30) => {
    "msg": "192.168.30.31"
}
ok: [192.168.77.130] => (item=vlan40) => {
    "msg": "192.168.40.31"
}
ok: [192.168.77.130] => (item=vlan70) => {
    "msg": "192.168.70.31"
}
ok: [192.168.77.130] => (item=vlan50) => {
    "msg": "192.168.50.31"
}

PLAY RECAP ***********************************************************************************************************
192.168.77.130             : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Run ad-hoc

Configure ansible.cfg to set the custom plugin directory:

1
2

[defaults]
vars_plugins       = /etc/ansible/vars_plugins

1
2
3
4
5
6
7
8
9

# ansible 192.168.77.130 -m debug -a 'var=gateway'
192.168.77.130 | SUCCESS => {
    "gateway": "192.168.30.254"
}

# ansible 192.168.77.130 -m debug -a 'var=vlan30'
192.168.77.130 | SUCCESS => {
    "vlan30": "192.168.30.31"
}