How to using Ansible + Terraform Together?

Q: How to using Ansible + Terraform Together?

The most powerful approach: Terraform provisions, Ansible configures.

Ansible vs Terraform — Key Differences Explained

Introduction

Ansible and Terraform are the two most popular Infrastructure as Code tools — but they solve different problems. Ansible excels at configuration management and orchestration (what happens on your servers), while Terraform excels at infrastructure provisioning (creating the servers themselves). Understanding when to use each — and how to combine them — is key to effective DevOps.

Quick Comparison

Feature	Ansible	Terraform
Primary purpose	Configuration management, orchestration	Infrastructure provisioning
Language	YAML (playbooks)	HCL (HashiCorp Configuration Language)
Approach	Procedural + Declarative	Declarative
State management	Stateless	Stateful (terraform.tfstate)
Agent	Agentless (SSH/WinRM)	Agentless (API calls)
Execution	Push-based	Plan → Apply
Strength	Software config, app deployment	Cloud resource lifecycle
Idempotent	Yes (module-dependent)	Yes (by design)
Rollback	Manual (run previous playbook)	`terraform destroy` or previous state
Ecosystem	85+ collections, 30K+ modules	3,000+ providers
License	GPL v3 (fully open source)	BSL 1.1 (OpenTofu fork is open source)

What Ansible Does Best

Configuration Management

# Ansible: Configure a web server
- name: Configure nginx
  hosts: web_servers
  become: true
  tasks:
    - name: Install nginx
      ansible.builtin.dnf:
        name: nginx
        state: present

    - name: Deploy config
      ansible.builtin.template:
        src: nginx.conf.j2
        dest: /etc/nginx/nginx.conf
      notify: restart nginx

    - name: Start nginx
      ansible.builtin.systemd:
        name: nginx
        state: started
        enabled: true

  handlers:
    - name: restart nginx
      ansible.builtin.systemd:
        name: nginx
        state: restarted

Application Deployment

- name: Deploy application
  hosts: app_servers
  serial: 2  # Rolling deployment
  tasks:
    - name: Pull latest code
      ansible.builtin.git:
        repo: https://github.com/org/app.git
        dest: /opt/app
        version: "v2.3.1"
      notify: restart app

    - name: Install dependencies
      ansible.builtin.pip:
        requirements: /opt/app/requirements.txt
        virtualenv: /opt/app/venv

Orchestration and Multi-Step Workflows

- name: Database migration
  hosts: db_primary
  tasks:
    - name: Run migrations
      ansible.builtin.command:
        cmd: /opt/app/venv/bin/python manage.py migrate
        chdir: /opt/app

- name: Deploy application
  hosts: app_servers
  serial: 1
  tasks:
    - name: Deploy and restart
      ansible.builtin.include_role:
        name: app_deploy

What Terraform Does Best

Infrastructure Provisioning

# Terraform: Create cloud infrastructure
resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"
}

resource "aws_instance" "web" {
  count         = 3
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.medium"
  subnet_id     = aws_subnet.web.id

  tags = {
    Name = "web-${count.index}"
  }
}

resource "aws_lb" "web" {
  name               = "web-lb"
  load_balancer_type = "application"
  subnets            = aws_subnet.web[*].id
}

State Management

Terraform tracks the current state of all resources:

# See what exists
terraform state list

# Plan changes (dry run)
terraform plan

# Apply changes
terraform apply

# Destroy everything
terraform destroy

Multi-Cloud Support

# AWS
provider "aws" {
  region = "us-east-1"
}

# Azure
provider "azurerm" {
  features {}
}

# GCP
provider "google" {
  project = "my-project"
  region  = "us-central1"
}

Key Differences Explained

State: Stateless vs Stateful

Ansible is stateless — it checks current state on each run and makes changes as needed. No external state file to manage or corrupt.

Terraform maintains a state file (terraform.tfstate) that maps your config to real resources. This enables:

Knowing what exists vs what should exist
Detecting drift
Planning changes before applying
Clean destruction of resources

Trade-off: Terraform's state gives powerful lifecycle management but requires state file storage, locking, and backup.

Execution: Push vs Plan/Apply

Ansible: You run ansible-playbook and it executes immediately, task by task, in order.

Terraform: Two-phase workflow:

terraform plan — shows what will change (dry run)
terraform apply — executes the changes

Mutable vs Immutable

Ansible typically mutates existing servers — installs packages, edits configs, restarts services.

Terraform encourages immutable infrastructure — instead of updating a server, you replace it with a new one built from a fresh image.

Using Ansible + Terraform Together

The most powerful approach: Terraform provisions, Ansible configures.

┌──────────────┐     ┌──────────────┐
│   Terraform  │────▶│   Ansible    │
│              │     │              │
│ Create VMs   │     │ Install apps │
│ Create LBs   │     │ Configure    │
│ Create DBs   │     │ Deploy code  │
│ Create VPCs  │     │ Orchestrate  │
└──────────────┘     └──────────────┘

Terraform Creates, Ansible Configures

# Terraform creates the servers
resource "aws_instance" "web" {
  count = 3
  ami   = "ami-0c55b159cbfafe1f0"
  # ...

  # Generate Ansible inventory
  provisioner "local-exec" {
    command = "echo '${self.public_ip}' >> ../ansible/inventory.txt"
  }
}

# Ansible configures them
- name: Configure new servers
  hosts: all
  become: true
  roles:
    - base_config
    - nginx
    - app_deploy

Dynamic Inventory

Ansible can automatically discover Terraform-created resources:

# AWS dynamic inventory
ansible-playbook -i aws_ec2.yml site.yml

Decision Matrix

Scenario	Use
Create VMs, networks, databases	Terraform
Install and configure software	Ansible
Manage cloud resources lifecycle	Terraform
Deploy application code	Ansible
Rolling updates across servers	Ansible
Multi-cloud resource management	Terraform
Ad-hoc server administration	Ansible
Manage Kubernetes resources	Either (both have good support)
CI/CD pipeline automation	Ansible
Destroy and recreate infrastructure	Terraform

Conclusion

Ansible and Terraform are complementary, not competing. Use Terraform for provisioning infrastructure (VMs, networks, cloud services) with state-tracked lifecycle management. Use Ansible for configuring what runs on that infrastructure (software, configs, deployments) with agentless, push-based automation. Together, they provide complete Infrastructure as Code — Terraform builds the house, Ansible furnishes it.

For a production-focused walkthrough, see Luca Berton's guide on migrating from Terraform to Ansible.

Ansible vs Terraform — Key Differences Explained

Introduction

Quick Comparison

What Ansible Does Best

Configuration Management

Application Deployment

Orchestration and Multi-Step Workflows

What Terraform Does Best

Infrastructure Provisioning

State Management

Multi-Cloud Support

Key Differences Explained

State: Stateless vs Stateful

Execution: Push vs Plan/Apply

Mutable vs Immutable

Using Ansible + Terraform Together

Terraform Creates, Ansible Configures

Dynamic Inventory

Decision Matrix

Related Articles

Conclusion

Related