ansible-automation

name	ansible-automation
description	Infrastructure automation and configuration management using Ansible playbooks, roles, and inventory. Use for deploying applications, patching, and managing servers.

Ansible Automation

Overview

Automate infrastructure provisioning, configuration management, and application deployment across multiple servers using Ansible playbooks, roles, and dynamic inventory management.

When to Use

• Configuration management
• Application deployment
• Infrastructure patching and updates
• Multi-server orchestration
• Cloud instance provisioning
• Container management
• Database administration
• Security compliance automation

Implementation Examples

1. Playbook Structure and Best Practices

# site.yml - Main playbook
---
- name: Deploy application stack
  hosts: all
  gather_facts: yes
  serial: 1  # Rolling deployment

  pre_tasks:
    - name: Display host information
      debug:
        var: inventory_hostname
      tags: [always]

  roles:
    - common
    - docker
    - application

  post_tasks:
    - name: Verify deployment
      uri:
        url: "http://{{ inventory_hostname }}:8080/health"
        status_code: 200
      retries: 3
      delay: 10
      tags: [verify]

# roles/common/tasks/main.yml
---
- name: Update system packages
  apt:
    update_cache: yes
    cache_valid_time: 3600
  when: ansible_os_family == 'Debian'

- name: Install required packages
  package:
    name: "{{ packages }}"
    state: present
  vars:
    packages:
      - curl
      - git
      - htop
      - python3-pip

- name: Configure sysctl settings
  sysctl:
    name: "{{ item.name }}"
    value: "{{ item.value }}"
    sysctl_set: yes
    state: present
  loop:
    - name: net.core.somaxconn
      value: 65535
    - name: net.ipv4.tcp_max_syn_backlog
      value: 65535
    - name: fs.file-max
      value: 2097152

- name: Create application user
  user:
    name: appuser
    shell: /bin/bash
    home: /home/appuser
    createhome: yes
    state: present

# roles/docker/tasks/main.yml
---
- name: Install Docker prerequisites
  package:
    name: "{{ docker_packages }}"
    state: present
  vars:
    docker_packages:
      - apt-transport-https
      - ca-certificates
      - curl
      - gnupg
      - lsb-release

- name: Add Docker GPG key
  apt_key:
    url: https://download.docker.com/linux/ubuntu/gpg
    state: present

- name: Add Docker repository
  apt_repository:
    repo: "deb https://download.docker.com/linux/ubuntu {{ ansible_distribution_release }} stable"
    state: present

- name: Install Docker
  package:
    name:
      - docker-ce
      - docker-ce-cli
      - containerd.io
    state: present

- name: Start Docker service
  systemd:
    name: docker
    enabled: yes
    state: started

- name: Add user to docker group
  user:
    name: appuser
    groups: docker
    append: yes

# roles/application/tasks/main.yml
---
- name: Clone application repository
  git:
    repo: "{{ app_repo_url }}"
    dest: "/home/appuser/app"
    version: "{{ app_version }}"
    force: yes
  become: yes
  become_user: appuser

- name: Copy environment configuration
  template:
    src: .env.j2
    dest: "/home/appuser/app/.env"
    owner: appuser
    group: appuser
    mode: '0600'
  notify: restart application

- name: Build Docker image
  docker_image:
    name: "myapp:{{ app_version }}"
    build:
      path: "/home/appuser/app"
      pull: yes
    source: build
    state: present
  become: yes

- name: Start application container
  docker_container:
    name: myapp
    image: "myapp:{{ app_version }}"
    state: started
    restart_policy: always
    ports:
      - "8080:8080"
    volumes:
      - /home/appuser/app:/app:ro
    env:
      NODE_ENV: "{{ environment }}"
      LOG_LEVEL: "{{ log_level }}"
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:8080/health"]
      interval: 30s
      timeout: 10s
      retries: 3

handlers:
  - name: restart application
    docker_container:
      name: myapp
      state: restarted

2. Inventory and Variables

# inventory/hosts.ini
[webservers]
web1 ansible_host=10.0.1.10
web2 ansible_host=10.0.1.11
web3 ansible_host=10.0.1.12

[databases]
db1 ansible_host=10.0.2.10 db_role=primary
db2 ansible_host=10.0.2.11 db_role=replica

[all:vars]
ansible_user=ubuntu
ansible_ssh_private_key_file=~/.ssh/id_rsa
ansible_python_interpreter=/usr/bin/python3

# inventory/group_vars/webservers.yml
---
app_version: "1.2.3"
app_repo_url: "https://github.com/myorg/myapp.git"
environment: production
log_level: INFO

# inventory/host_vars/web1.yml
---
server_role: primary
max_connections: 500

3. Ansible Deployment Script

#!/bin/bash
# ansible-deploy.sh - Deploy using Ansible

set -euo pipefail

ENVIRONMENT="${1:-dev}"
PLAYBOOK="${2:-site.yml}"
INVENTORY="inventory/hosts.ini"
LIMIT="${3:-all}"

echo "Deploying with Ansible: $PLAYBOOK"
echo "Environment: $ENVIRONMENT"
echo "Limit: $LIMIT"

# Syntax check
echo "Checking Ansible syntax..."
ansible-playbook --syntax-check \
  -i "$INVENTORY" \
  -e "environment=$ENVIRONMENT" \
  "$PLAYBOOK"

# Dry run
echo "Running dry-run..."
ansible-playbook \
  -i "$INVENTORY" \
  -e "environment=$ENVIRONMENT" \
  -l "$LIMIT" \
  --check \
  "$PLAYBOOK"

# Ask for confirmation
read -p "Continue with deployment? (y/n): " -r
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
  echo "Deployment cancelled"
  exit 1
fi

# Execute playbook
echo "Executing playbook..."
ansible-playbook \
  -i "$INVENTORY" \
  -e "environment=$ENVIRONMENT" \
  -l "$LIMIT" \
  -v \
  "$PLAYBOOK"

echo "Deployment complete!"

# Run verification
echo "Running post-deployment verification..."
ansible-playbook \
  -i "$INVENTORY" \
  -e "environment=$ENVIRONMENT" \
  -l "$LIMIT" \
  verify.yml

4. Configuration Template

# roles/application/templates/.env.j2
# Environment Configuration
NODE_ENV={{ environment }}
LOG_LEVEL={{ log_level }}
PORT=8080

# Database Configuration
DATABASE_URL=postgresql://{{ db_user }}:{{ db_password }}@{{ db_host }}:5432/{{ db_name }}
DATABASE_POOL_SIZE=20
DATABASE_TIMEOUT=30000

# Cache Configuration
REDIS_URL=redis://{{ redis_host }}:6379
CACHE_TTL=3600

# Application Configuration
APP_NAME=MyApp
APP_VERSION={{ app_version }}
WORKERS={{ ansible_processor_vcpus }}

# API Configuration
API_TIMEOUT=30000
API_RATE_LIMIT=1000

# Monitoring
SENTRY_DSN={{ sentry_dsn | default('') }}
DATADOG_API_KEY={{ datadog_api_key | default('') }}

Ansible Commands

# List all hosts in inventory
ansible all -i inventory/hosts.ini --list-hosts

# Run ad-hoc command
ansible webservers -i inventory/hosts.ini -m ping

# Execute playbook
ansible-playbook -i inventory/hosts.ini site.yml

# Syntax check
ansible-playbook --syntax-check site.yml

# Dry-run
ansible-playbook -i inventory/hosts.ini site.yml --check

# Run with specific tags
ansible-playbook -i inventory/hosts.ini site.yml -t deploy

Best Practices

✅ DO

• Use roles for modularity
• Implement proper error handling
• Use templates for configuration
• Leverage handlers for idempotency
• Use serial deployment for rolling updates
• Implement health checks
• Store inventory in version control
• Use vault for sensitive data

❌ DON'T

• Use command/shell without conditionals
• Copy files without templates
• Run without check mode first
• Mix environments in inventory
• Hardcode values
• Ignore error handling
• Use shell for simple tasks

Resources

• Ansible Official Documentation
• Ansible Galaxy - Community Roles
• Ansible Best Practices
• Ansible Playbook Best Practices