Configuration management tools

Where IaC defines infrastructure components, configuration management tools define the configuration of those infrastructure components. For example, a VM can be deployed using IaC, but the software that runs on that VM, or its operating system parameters, must be configured afterwards. This is a job for configuration management tools. Configuration management also uses declarative languages that define the desired state of the configuration.

The most used configuration management tools are Ansible, Puppet, and Chef.

Ansible uses YAML playbooks to define resources and can be used to automate server provisioning, configuration management, application deployment, and more. Ansible is agentless and can be used to manage a wide range of platforms, including cloud and on-premises servers.

As an example, the following Ansible playbook creates a httpd webserver on a Linux server:

- name: Install httpd
  hosts: webserver
  become: yes
  tasks:
    - name: Install httpd package
      yum:
        name: httpd
        state: present
    - name: Start httpd service
      service:
        name: httpd
        state: started
        enabled: yes

Puppet is a configuration management tool that can be used to manage servers, networks, storage, and more. The following Puppet manifest creates a httpd webserver on a Linux server:

# Install httpd package
package { 'httpd':
  ensure => 'installed',
}

# Start httpd service
service { 'httpd':
  ensure => 'running',
  enable => true,
}

Chef is another configuration management tool. It uses a domain-specific language called Ruby to define infrastructure resources and provides features like idempotency, versioning, and testing. Chef can be used to manage servers, networks, storage, and more.

The following Chef recipe creates a httpd webserver on a Linux server:

# Install Apache HTTP Server (httpd) package
package 'httpd' do
  action :install
end

# Start and enable httpd service
service 'httpd' do
  action [:start, :enable]
end

Configuration management tools are often run periodically, for instance every few hours, to ensure any manual change to the deployed environment is reverted to the state as defined in the configuration management tool.

This entry was posted on Wednesday 01 October 2025