devops-configuration-management-ansible

id: devops-configuration-management-ansible aliases: [ ] tags: - roadmap - devops - devops-configuration-management - ready - online - ansible - configurations - – 

# devops-configuration-management-ansible

## Contents

__Roadmap info from [ roadmap website ] (https://roadmap.sh/devops/ansible@h9vVPOmdUSeEGVQQaSTH5) __

  ## Ansible

  Ansible
  is
  an
  open-source
  automation
  tool
  used
  for
  configuration
  management, application deployment, and task automation. It simplifies the process of managing and orchestrating infrastructure by using a declarative language to define desired states and configurations. Ansible operates using YAML files, called playbooks, which describe the tasks to be executed on remote systems. It employs an agentless architecture, meaning it uses SSH or other remote protocols to execute tasks on target machines without requiring additional software to be installed. Ansible is widely used for automating repetitive tasks, ensuring consistency, and managing large-scale deployments across various environments.

Visit the following resources to learn more:

Examples

Here is an Ansible playbook that creates a virtual machine with Postgres installed: 

---
- name: Create a VM with Postgres
hosts: localhost
become: true

tasks:
- name: Install virt-install and libvirt
package:
name: virt-install, libvirt
state: present
- name: Create a virtual machine
virt_install:
name: myvm
memory: 4096
vcpus: 2
disk: /path/to/vm/disk.img
network: bridge=br0,model=virtio

- name: Install Postgres
package:
name: postgresql-server
state: present

- name: Configure Postgres
template:
src: templates/postgresql.conf.j2
dest: /etc/postgresql/13/main/postgresql.conf
mode: '0644'
notify: restart postgre
handlers:
- name: restart postgre
service:
name: postgresql
state: restarted

Let me explain what this playbook does:

  1. The first task installs the virt-install and libvirt packages, which are required to create a virtual machine.
  2. The second task uses the virt_install module to create a new virtual machine with 4GB of RAM, 2 CPUs, and a disk image at /path/to/vm/disk.img. It also sets up a network bridge using the virtio model.
  3. The third task installs the Postgres server package using the package module.
  4. The fourth task uses a template to configure the Postgres configuration file (postgresql.conf) and notifies the restart postgre handler to restart the Postgres service.

You’ll need to create a templates directory with a postgresql.conf.j2 template file that contains the desired Postgres configuration settings.

Here’s an example postgresql.conf.j2 template: 

listen_addresses = '*'
port = 5432
max_connections = 100

This template sets up the Postgres listener to listen on all available network interfaces, sets the port to 5432, and limits the maximum number of connections to 100.

To use this playbook, save it as a YAML file (e.g., create_vm_with_postgres.yml) and then run it using Ansible: 

ansible-playbook -i <path/to/inventory> create_vm_with_postgres.yml

Replace <path/to/inventory> with the path to your Ansible inventory file.

Inventory 

graph TD
A[Ansible Inventory]

B[Local Inventory]
C[Facts collected from host/device facts modules]
D[Built using local system information]

E[Remote Inventory]
F[Came from connecting to other hosts via SSH/Telnet/VPN]
G[Shared across multiple environments e.g., development, production]

A --> B
B --> C
B --> D
A --> E
E --> F
E --> G

When to Use Inventory 

mindmap
When to Use Inventory
Complex systems with multiple hosts and network devices
Simplified management of infrastructure changes without downtime
Enhanced troubleshooting capabilities
Avoid repetitive manual tasks through automation

AWX