Ten Useful Ansible Modules

Here are some ansible modules that I have found useful. Some of these modules may not be as popular as well. But for clean playbooks I believe they are worth the look.

The File Module

File module sets attributes of files, symlinks, and directories, it can also remove file, symlinks or directories.

Examples

- file:
    path: /etc/example.conf
    owner: exampleowner
    group: examplegroup
    mode: 0755
- file:
    src: /file/to/link/to
    dest: /path/to/symlink
    owner: exampleowner
    group: examplegroup
    state: link

file - Sets attributes of files - Ansible Documentation

The SELinux Module

This module will allow you to configure the SELinux module on linux.

Examples

# Enable SELinux
- selinux:
    policy: targeted
    state: enforcing

# Put SELinux in permissive mode, logging actions that would be blocked.
- selinux:
    policy: targeted
    state: permissive

# Disable SELinux
- selinux:
    state: disabled

selinux - Change policy and state of SELinux - Ansible Documentation

The SEBoolean Module

SEBoolean Module toggles selinux booleans in your environment. This is helpful do to the fact that you just have to use selinux boolean name and modify the state or persistents in the playbook.

Example

- seboolean:
    name: allow_httpd_anon_write
    state: yes
    persistent: yes

Listing Booleans

seboolean - Toggles SELinux booleans. - Ansible Documentation

The RAW Module

If you are new to ansible raw module is for you it creates a low-down dirty command via ssh. This is useful and should be done in the following cases.

1. installing python-simplejson on older Python 2.4 and before since there are many dependencies that are needed most core modules
2. Connecting to devices that do not have python installed.

Example:

- name: Bootstrap a legacy python 2.4 host
  raw: yum -y install python-simplejson

- name: Run a command that uses non-posix shell-isms (in this example /bin/sh doesn't handle redirection and wildcards together but bash does)
  raw: cat < /tmp/*txt
  args:
    executable: /bin/bash

raw - Executes a low-down and dirty SSH command - Ansible Documentation

The Mount Module

This module controls mount points pointed to /etc/fstab. The is useful do to the fact that you can specify the type, path state and other property's right from Ansible.

Example

- name: Mount DVD read-only
  mount:
    path: /mnt/dvd
    src: /dev/sr0
    fstype: iso9660
    opts: ro
    state: present

mount - Control active and configured mount points - Ansible Documentation

The User Module

The module manages users accounts with there attributes. This is handy do to the fact that the user properties and attributes can all be configured from this Ansible module.

Example

# Add the user 'exampleuser' with a specific uid and a primary group of 'admin'
- user:
    name: exampleuser
    comment: "Example User"
    uid: 1040
    group: admin
# Remove the user 'exampleuser'
- user:
    name: exampleuser
    state: absent
    remove: yes

user - Manage user accounts - Ansible Documentation

The Group Module

The module allows you to manage groups on a host. The modules have all the defined properties need to modify groups on a system.

Example

 # Example command for creating a group in this ansible module
- group:
    name: testgroup
    state: present

group - Add or remove groups - Ansible Documentation

The Mail Module

This module is useful for sending emails. Whether you plan to use them for Error notifications or completion notification. It is a useful addition to the ansible module toolkit.

Example

# Example playbook sending mail to root
- mail:
    subject: 'System {{ ansible_hostname }} has been successfully provisioned.'
  delegate_to: localhost

# Sending an e-mail using Gmail SMTP servers
- mail:
    host: smtp.gmail.com
    port: 587
    username: username@gmail.com
    password: mysecret
    to: Example Uesr<example.user@example.com>
    subject: Ansible-report
    body: 'System {{ ansible_hostname }} has been successfully provisioned.'
  delegate_to: localhost

mail - Send an email - Ansible Documentation

The Git Module

This module will allow you to manage git checkouts of repositories to deploy software. This is very useful if you organization is using CI/CD since ansible could provision the servers and then configure the servers with source code via Git.

Example

# Example git checkout from Ansible Playbooks
- git:
    repo: 'https://testserver.example.org/path/to/repo.git'
    dest: /srv/checkout
    version: release-0.22

# Example read-write git checkout from github
- git:
    repo: ssh://git@github.com/mylogin/hello.git
    dest: /home/mylogin/hello

# Example just ensuring the repo checkout exists
- git:
    repo: 'https://testserver.example.org/path/to/repo.git'
    dest: /srv/checkout
    update: no

git - Deploy software (or files) from git checkouts - Ansible Documentation

The Script Module

This module takes the script name followed by space-delimited arguments. The script that runs will be copy locally to the remote system and ran automatically. This is a great feature because the other way to run a script on ansible is to use the copy module to machine with the correct permissions. Then call the script with the command or shell module. The script command takes care of all of that automatically. You can also set the return to the register and debug modules.

Example

- script: /some/local/sample_script.sh --some-arguments testvar
  args:
    creates: /the/created/sample.txt

script - Runs a local script on a remote node after transferring it - Ansible Documentation

Try linuxacademy.com they have a great course on Ansible called Using Ansible for Configuration Management and Deployments.