Ansible Search String in File: lineinfile & regex Guide — Video Tutorial

How to search for strings in files with Ansible. Use lineinfile regex, check mode, shell grep, and slurp module to find and manage text patterns.

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How to Search for a String in a File with Ansible?
Ansible module lineinfile
Parameters
Links
Playbook
code
string present
string different
file not present
Conclusion

How to Search for a String in a File with Ansible? Ansible module lineinfile > `ansible.builtin.lineinfile`: insert, update and remove a single line of text in a file Today we're talking about the Ansible module `lineinfile`. The full name is `ansible.builtin.lineinfile`, which means that is part of the collection of modules "builtin" with ansible and shipped with it. It's a module pretty stable and out for years and it supports a large variety of operating systems. You are able to insert, update and remove a single line of text in a file. Parameters - `path` string - file path - `line` string - text - `insertafter`/`insertbefore` string - EOF/regular expression - `validate` string - validation command - `create` boolean - create if not exist - `state` string - present/absent - `mode`/`owner`/`group` - permission - `setype`/`seuser`/`selevel` - SELinux This module has some parameters to perform any tasks. The only required is "path", where you specify the filesystem path of the file you're going to edit. "line" is the line of text we would like to insert in the file, easy! By default, the text is going to be inserted at the end of the file, but we could personalize it in a specific position with insertafter/insertbefore. If there is any tool to validate the file we could specify in the validate parameter, very useful for configuration files. If the file does not exist we could also "create" it! Usually, we would like to insert a text line but we could also remove using state in conjunction with parameter absent. Let me also highlight that we could also specify some permissions or SELinux properties. Links - [`ansible.builtin.lineinfile`](https://docs.ansible.com/ansible/latest/collections/ansible/builtin/lineinfile_module.html) Playbook How to Search for a String in a File. How to search for a pattern in a file and return the result using only the Ansible built-in lineinfile module. code ```yaml --- - name: search Playbook hosts: all vars: myfile: "/etc/ssh/sshd_config" myline: 'PasswordAuthentication no' become: true tasks: - name: string found ansible.builtin.lineinfile: name: "{{ myfile }}" line: "{{ myline }}" state: present check_mode: true register: conf failed_when: (conf is changed) or (conf is failed) ``` string present - remote host ```bash $ ssh devops@demo.example.com [devops@demo ~]$ sudo su [root@demo devops]# grep 'PasswordAuthentication no' /etc/ssh/sshd_config PasswordAuthentication no [root@demo devops]# ``` - Ansible execution ```bash $ ansible-playbook -i virtualmachines/demo/inventory file_management/file_search.yml PLAY [search Playbook] ******************************************************************************** TASK [Gathering Facts] **************************************************************************** ok: [demo.example.com] TASK [string found] ******************************************************************************* ok

About this tutorial

Author: Luca Berton
Difficulty: Advanced
Read time: 7 min
Category: troubleshooting

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