How ansible can call multiple files under path option as a variable - linux

Question

I am just learning ansible and trying to understand how can i include multiple file in the path option in ansible replace module.
I have three files where i need to replace a old hostname with new hostanme.
Files are :
- /etc/hosts
- /etc/hosts.custom
- /etc/hosts-backup
Below Simple Play works fine:
- name: Replace string in hosts file
hosts: all
gather_facts: false
tasks:
- name: Replace string in host file
replace:
path: /etc/hosts
regexp: "171.20.20.16 fostrain.example.com"
replace: "171.20.20.16 dbfoxtrain.example.com"
backup: yes
However, after lot of googling i see this can be done as follows, but in case i have multiple files and those needs to be called as a variable in different modules, How we can define then in such a way so as to call them by variable name.
Below is Just what i am trying to understand..
- name: Replace string in hosts file
hosts: all
gather_facts: false
tasks:
- name: Checking file contents
slurp:
path: "{{ ?? }}" <-- How to check these three files here
register: fileCheck.out
- debug:
msg: "{{ (fileCheck.out.content | b64decode).split('\n') }}"
- name: Replace string in host file
replace:
path: "{{ item.path }}"
regexp: "{{ item:from }}"
replace: "{{ item:to }}"
backup: yes
loop:
- { path: "/etc/hosts", From: "171.20.20.16 fostrain.example.com", To: "171.20.20.16 dbfoxtrain.example.com"}
- { Path: "/etc/hosts.custom", From: "171.20.20.16 fostrain.example.com", To: "171.20.20.16 dbfoxtrain.example.com"}
- { Path: "/etc/hosts-backup", From: "171.20.20.16 fostrain.example.com", To: "171.20.20.16 dbfoxtrain.example.com"}
I will appreciate any help.

Answer 1

Create couple of variables; a list with all the files, from and to replacement strings or divide them by ip and domain. Then loop over all the files using the file list variable and use from and to replacement variables for each file. If multiple ip and domain mapping is required then you need to adjust the structure further. So recommend going through ansible documentation on using variables and loops for more details.
Playbook may look like below. Have used a minor regex and you can adjust as required.
- name: Replace string in hosts file
hosts: all
gather_facts: false
vars:
files:
- /etc/hosts
- /etc/hosts.custom
- /etc/hosts-backup
from_ip: "171.20.20.16"
from_dn: "fostrain.example.com"
to_ip: "171.20.20.16"
to_dn: "dbfoxtrain.example.com"
tasks:
- name: Replace string in host file
replace:
path: "{{ item }}"
regexp: "{{ from_ip }}\\s+{{ from_dn }}"
replace: "{{ to_ip }} {{ to_dn }}"
loop: "{{ files }}"
If you want to see the contents of each file then slurp and debug modules can be used like below:
- slurp:
path: "{{ item }}"
loop: "{{ files }}"
register: contents
- debug:
msg: "{{ (item.content | b64decode).split('\n') }}"
loop: "{{ contents.results }}"