[](https://www.linkedin.com/in/nirgeier/) [](mailto:nirgeier@gmail.com) [](mailto:nirg@codewizard.co.il) If you appreciate the effort, Please this project

Lab 003 - Commands & Modules¶

• In this section, we will cover Module

• Modules are important elements and are the “heart” of ansible.

• Lab 003 - Commands \& Modules

• What is a Module?
  • Sample Module - The build in ‘ping’ Module
  • The ping module
• List of modules
• Ad-hoc command
  • ping
  • shell
  • dnf
  • setup

What is a Module?¶

• A module is a unit of code in Ansible that performs common operations in infrastructure management, such as configuring systems, installing software, or managing resources.
• Ansible has a huge number of modules.
• You can browser and search ansible builtin modules under the Build In Ansible Modules
• Module are used for task automation.

Sample Module - The build in ‘ping’ Module¶

• In this lab we will explore the build in ping Module
• The source code for this module is: https://github.com/ansible/ansible/blob/devel/lib/ansible/modules/ping.py

01. The ping module¶

• Source: https://github.com/ansible/ansible/blob/devel/lib/ansible/modules/ping.py
• Docs: https://docs.ansible.com/ansible/latest/collections/ansible/builtin/ping_module.html
  

From the docs:

• ansible.builtin.ping module – Try to connect to host, verify a usable python and return pong on success
• This module is part of ansible-core and included in all Ansible installations.
• In most cases, you can use the short module name ping

• Now we will break down the code, fell free to browse and look on the full code Browse the code.

01.01. The ping source code¶

• At the time of writing this tutorial, the “implementation” of the ping is the following

  RETURN = '''
  ping:
      description:  Value provided with the O(data) parameter.
      returned:     success
      type:         str
      sample:       pong
  '''
  
  from ansible.module_utils.basic import AnsibleModule
  
  def main():
      module = AnsibleModule(
          argument_spec=dict(
              data=dict(type='str', default='pong'),
          ),
          supports_check_mode=True
      )
  
      if module.params['data'] == 'crash':
          raise Exception("boom")
  
      result = dict(
          ping=module.params['data'],
      )
  
      module.exit_json(**result)
  
  if __name__ == '__main__':
      main()
  

02. List of modules¶

• Modules are managed in the form of `collection’, and each collection contains multiple related modules.
• List of Collections

Note: Up to version 2.9 Ansible included all modules by default, but the number of modules increased so much that it was changed to the current format (2.10 and later)

02. Using modules¶

• By default Ansible is installed with ansible.builtin as the only collection.
• A list of modules that are available in the ansible.builtin click here

02.01. Find modules for you OS¶

• To see which modules are available for you OS use this command:

  ansible-doc -l
  
  ### Output (only first few lines)
  add_host        Add a host (and alternatively a group) to the ansible-playbook in-memory inventor...
  apt             Manages apt-packages
  apt_key         Add or remove an apt key
  apt_repository  Add and remove APT repositories
  assemble        Assemble configuration files from fragments
  assert          Asserts given expressions are true
  async_status    Obtain status of asynchronous task
  blockinfile     Insert/update/remove a text block surrounded by marker lines
  

02.02. Documentation¶

• To view documentation for a specific module:

  # Display the ping documentation
  $ ansible-doc ping
  
  > ANSIBLE.BUILTIN.PING    (/opt/homebrew/Cellar/ansible/9.4.0_1/libexec/lib/python3.12/site-packages/ansible/modules/ping>
  
        A trivial test module, this module always returns `pong' on successful contact. It does
        not make sense in playbooks, but it is useful from `/usr/bin/ansible' to verify the
        ability to login and that a usable Python is configured. This is NOT ICMP ping, this is
        just a trivial test module that requires Python on the remote-node. For Windows targets,
        use the [ansible.windows.win_ping] module instead. For Network targets, use the
        [ansible.netcommon.net_ping] module instead.
  
  ADDED IN: historical
  
  OPTIONS (= is mandatory):
  
  - data
        Data to return for the `ping' return value.
  

03. Common Ad-hoc command¶

• Invoking a module is referred to as Ad-hoc command.
• The syntax is the following:

  $ ansible <servers> -m <module_name> -a '<parameters>'
  

  | CLI option | Description | | ------------------ | --------------------------------------------------------------------------- | | <servers> | Any server (singel, group or all) as defined in the inventory file | | -m <module_name> | Specifies the module name. | | -a <parameters> | Specifies the parameters to be passed to the module. Optional in most cases |

03.01. ping¶

• Docs: https://docs.ansible.com/ansible/latest/collections/ansible/builtin/ping_module.html
• We are already familiar with ping

[!TIP] This is a module that determines whether Ansible can “communicate as Ansible” to the node it is working on (which is different from ICMP used in the network). Ping module parameters are optional.

• Usage:

# Ping all server in the inventory
ansible all -m ping

# In our demo lab we will execute it like this:
docker exec ansible-controller sh -c "cd /labs-scripts && ansible all -m ping"

• Output

  linux-server-1 | SUCCESS => {
      "ansible_facts": {
          "discovered_interpreter_python": "/usr/bin/python3"
      },
      "changed": false,
      "ping": "pong"
  }
  linux-server-3 | SUCCESS => {
      "ansible_facts": {
          "discovered_interpreter_python": "/usr/bin/python3"
      },
      "changed": false,
      "ping": "pong"
  }
  linux-server-2 | SUCCESS => {
      "ansible_facts": {
          "discovered_interpreter_python": "/usr/bin/python3"
      },
      "changed": false,
      "ping": "pong"
  }
  

03.03. shell¶

• Docs: https://docs.ansible.com/ansible/latest/collections/ansible/builtin/shell_module.html

[!TIP] This is a module that Execute shell commands on targets

# Lets get the hostname of the server
ansible all -m shell -a 'hostname'

# In our demo lab we will execute it like this:
docker exec ansible-controller sh -c "cd /labs-scripts && ansible all -m shell -a 'hostname'"

• Output¶

  # ansible all -m shell -a 'hostname' 
  linux-server-3 | CHANGED | rc=0 >>
  linux-server-3
  linux-server-2 | CHANGED | rc=0 >>
  linux-server-2
  linux-server-1 | CHANGED | rc=0 >>
  linux-server-1
  

Hands-on¶

1. Figure out way to run the following (shell) command with Ansible, on any of the servers:

   # Get kernel information
   uname -a
   
   # Get a date
   date
   

2. Use the ansible command module to print out the previous shell commands.

3. Try to run the following command: git config -l. > What is the result of this command?

Solution¶

# Using the shell module
docker exec ansible-controller sh -c "cd /labs-scripts && ansible linux-server-1 -m shell -a 'uname -a'"

#Using the ansible `command` module
docker exec ansible-controller sh -c "cd /labs-scripts && ansible linux-server-1 -m command -a 'uname -a'"

# Using the shell module
docker exec ansible-controller sh -c "cd /labs-scripts && ansible linux-server-1 -m shell -a 'date'"

#Using the ansible `command` module
docker exec ansible-controller sh -c "cd /labs-scripts && ansible linux-server-1 -m command -a 'date'"

:arrow_backward: /Labs/002-no-inventory  Back to labs list  /Labs/004-playbooks :arrow_forward: