How to list files and directories in long format with Ansible?

Introduction

Ansible is a widely-used IT automation tool that simplifies infrastructure management and deployment. In this tutorial, we will dive into the process of listing files and directories in long format using Ansible, equipping you with the knowledge to streamline your Ansible-powered workflows.

Skills Graph

Understanding Ansible Basics

Ansible is a powerful open-source automation tool that simplifies the process of managing and configuring IT infrastructure. It is designed to be easy to use, with a focus on simplicity and readability. Ansible uses a declarative approach, where you define the desired state of your infrastructure, and Ansible takes care of making it happen.

What is Ansible?

Ansible is a configuration management and orchestration tool that allows you to automate a wide range of tasks, from provisioning servers to deploying applications. It uses a simple, human-readable language called YAML to describe the desired state of your infrastructure, and it can be used to manage both physical and virtual machines, as well as cloud-based resources.

Ansible Architecture

Ansible uses a client-server architecture, where the "control node" (the machine running the Ansible commands) communicates with the "managed nodes" (the machines being managed by Ansible) over SSH. Ansible does not require any special software to be installed on the managed nodes, as it uses the built-in SSH capabilities of the operating system.

Ansible Playbooks

Ansible uses "playbooks" to define the desired state of your infrastructure. Playbooks are written in YAML and contain a series of "plays" and "tasks" that describe the actions to be performed on the managed nodes. Here's an example of a simple Ansible playbook:

- hosts: all
  tasks:
    - name: Install Apache
      apt:
        name: apache2
        state: present
    - name: Start Apache
      service:
        name: apache2
        state: started

This playbook installs the Apache web server on all managed nodes and starts the Apache service.

Listing Files and Directories

One of the common tasks in system administration is to list the files and directories on a remote system. Ansible provides a built-in module called ansible.builtin.ls to list the contents of a directory in a declarative way.

Using the ansible.builtin.ls Module

The ansible.builtin.ls module allows you to list the contents of a directory on a remote system. Here's an example playbook that lists the contents of the /etc directory:

- hosts: all
  tasks:
    - name: List contents of /etc
      ansible.builtin.ls:
        path: /etc
      register: etc_contents
    - name: Print the contents of /etc
      debug:
        var: etc_contents.files

In this example, the ansible.builtin.ls module is used to list the contents of the /etc directory, and the results are stored in the etc_contents variable. The debug task is then used to print the contents of the etc_contents.files variable, which contains a list of file and directory objects.

Listing Files in Long Format

To list the files and directories in long format, you can use the long option in the ansible.builtin.ls module. This will provide more detailed information about each item, such as the file permissions, owner, group, size, and modification time. Here's an example:

- hosts: all
  tasks:
    - name: List contents of /etc in long format
      ansible.builtin.ls:
        path: /etc
        long: yes
      register: etc_contents
    - name: Print the contents of /etc in long format
      debug:
        var: etc_contents.files

This playbook will output the contents of the /etc directory in long format, with each file or directory displayed on a separate line with its detailed information.

Exploring Long Format Listing

The long format listing provided by the ansible.builtin.ls module offers a wealth of information about the files and directories in a directory. Let's dive deeper into understanding the different components of the long format listing.

Understanding the Long Format Listing

When you use the long: yes option in the ansible.builtin.ls module, the output will include the following information for each file or directory:

Here's an example of the long format listing for the /etc directory:

- hosts: all
  tasks:
    - name: List contents of /etc in long format
      ansible.builtin.ls:
        path: /etc
        long: yes
      register: etc_contents
    - name: Print the contents of /etc in long format
      debug:
        var: etc_contents.files

The output of this playbook will look similar to the following:

"files": [
    {
        "mode": "-rw-r--r--",
        "owner": "root",
        "group": "root",
        "size": 1024,
        "modified": "2023-04-01 12:34:56",
        "name": "file1.txt"
    },
    {
        "mode": "drwxr-xr-x",
        "owner": "root",
        "group": "root",
        "size": 4096,
        "modified": "2023-04-02 09:15:22",
        "name": "directory1"
    }
]

This output provides a detailed view of the files and directories in the /etc directory, including their permissions, ownership, size, and modification time.

Filtering the Long Format Listing

You can also use the ansible.builtin.ls module to filter the long format listing based on specific criteria, such as file type or size. For example, to list only the directories in the /etc directory, you can use the following playbook:

- hosts: all
  tasks:
    - name: List directories in /etc in long format
      ansible.builtin.ls:
        path: /etc
        long: yes
        file_type: directory
      register: etc_dirs
    - name: Print the directories in /etc in long format
      debug:
        var: etc_dirs.files

This playbook will output only the directories in the /etc directory, with their detailed information in the long format.

Summary

By the end of this Ansible tutorial, you will have a solid understanding of how to list files and directories in long format, empowering you to efficiently manage and navigate your infrastructure using the power of Ansible.