I need to replace the first occurrence of a certain string in a specific file.

I think about to use the replace module of Ansible for this.

- hosts: abc
  tasks:
  - name: Replace first occurence of specific string
    replace:
      path: /etc/config/abc_host/application.yml
      regexp: 'Unix'
      replace: "Linux"

This would replace all occurences of Unix with Linux in this specific .yml-file. But I also have some other hosts (def_host, ghi_host etc.) for which I would I like to replace only the first occurrence of Unix with Linux.

So, there are two issues to solve:

First, using the hostnames as variable in path. Instead of hard-coding abc_host.yml I want something like path: /etc/config/($host)_host/application.yml.

Second, I just want to replace the first occurrence of the specific string (and not any other following occurrences of it).

CodePudding user response：

For the first part you can use variables like ansible_hostname and inventory_hostname, eg. path: /etc/config/{{ ansible_hostname }}_host/application.yml (see this post for the differences).

To solve the second part you could use the lineinfile module like this:

  - name: Ansible replace string example
    lineinfile:
      path: /etc/config/{{ ansible_hostname }}_host/application.yml
      regexp: 'Unix'
      line: "Linux"
      firstmatch: yes
      state: present