How to replace or paste text into a file in Ansible?

Question

Regular Expressions

For example, there is some kind of config, it has a line with parameters. The string can contain different parameters, the entire string cannot be replaced.
How can Ansible find the desired text, replace if it does not match and insert if it is missing in a certain place after a certain line?
file:

ServerConfig=" ip=10.0.0.0 dns=10.0.0.1 name=webserver"

You need to replace name=webserver with name=dbserver, if there is no line, then add it.

My attempts:

---
- hosts: webserver
  vars:
    config:
      - { param: name=, value: dbserver }
  tasks:
    - name: change param
      become: yes
      lineinfile:
        backup: yes
        backrefs: yes
        path: /etc/file/config
        regexp: '^ServerConfig=/"(?!.*\b{{ item.param }}{{ item.value }}\b).*)$'
        line: '\1{{ item.param }}{{ item.value }}\2'
        state: present
   loop: "{{ config }}"

Answer 1

Here is such a funny regex

ServerConfig="(.*)\b(name=[^\s]+)\b(.*)"|"(.*)\b(name=[^\s]+)?"

and replacement, respectively,
\1name=xxx\3\4
True, in this case, name=xxx will be inserted at the beginning, and not at the end of the line, if it was not there before
https://regex101.com/r/MILkYr/1/
ps and although it is possible to the end with such a replacement
\1\4name=xxx\3

Answer 2

I would make a config template and form the final config from it in a controlled manner.

Answer 3

What is the problem? Can't write a regular expression?
Options:

1. Regular expression with search and replace
   
2. blockinfile module
   
3. Sample