Ansible append text to line in certain section of INI file - linux

Question

I would like to know if there is a way using Ansible to append text to the end of a line in certain section of a file, an example is going to clarify what I want to do:
Think of a file like this:
[section01]
path = /home/section01
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = mexico,usa,canada
[section02]
path = /home/section02
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = mexico,usa,canada
[section03]
path = /home/section03
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = mexico,usa,canada
I would like to add "brazil" on host_allow in [section02] to get this "new file"
[section01]
path = /home/section01
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = mexico,usa,canada
[section02]
path = /home/section02
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = mexico,usa,canada,brazil
[section03]
path = /home/section03
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = mexico,usa,canada

Answer 1

As #Dan Farrell mentioned in the comments, you are better off generating the entire file as partial updates can be unreliable, and problematic.
You can however use ansible templates to accomplish this as well.
You create a template file(file.ini for example) with the contents below(removed other blocks for brevity). This file would contain the full INI file contents.
[section02]
path = /home/section02
read only = yes
list = yes
uid = apache
gid = apache
hosts deny = 0.0.0.0/0.0.0.0
hosts allow = {{allow_hosts}}
Then, in your playbook, add a task to template this file.
- name: Template INI file
template:
dest: "/path/to/some/file.ini"
src: file.ini
mode: 664
owner: root
group: root
When you instantiate the playbook, you can pass the full list of allowed hosts via extra-vars.
ansible-playbook -i hosts --extra-vars="allow_hosts=mexico,usa,canada,brazil" my-playbook.yml
This however will only work for you if you know all of the allowed hosts at the time the playbook is run.