opentofu-migration

OpenTofu Migration

Migrate infrastructure-as-code from HashiCorp Terraform to the open-source OpenTofu fork.

When to Use This Skill

Use this skill when:

• Migrating from Terraform to OpenTofu for licensing reasons
• Setting up a new IaC project and evaluating OpenTofu vs Terraform
• Updating CI/CD pipelines to use OpenTofu
• Configuring the OpenTofu provider registry

Prerequisites

• Existing Terraform codebase (0.13+)
• OpenTofu CLI installed
• State backend access (S3, GCS, Azure Blob, etc.)

Install OpenTofu

# macOS
brew install opentofu

# Linux (Debian/Ubuntu)
curl --proto '=https' --tlsv1.2 -fsSL https://get.opentofu.org/install-opentofu.sh \
  -o install-opentofu.sh
chmod +x install-opentofu.sh
./install-opentofu.sh --install-method deb
rm install-opentofu.sh

# Linux (RPM)
./install-opentofu.sh --install-method rpm

# Docker
docker run --rm -v $(pwd):/workspace -w /workspace \
  ghcr.io/opentofu/opentofu:latest init

# Verify installation
tofu --version

Migration Checklist

1. Verify Compatibility

# OpenTofu reads Terraform state files directly — no migration needed
# Check your Terraform version (must be <= 1.6.x for full compat)
terraform version

# Run plan with OpenTofu against existing state
tofu init
tofu plan

2. Replace CLI Commands

3. Update Provider Lock File

# Remove Terraform lock and regenerate for OpenTofu
rm .terraform.lock.hcl
tofu init -upgrade

# Verify providers resolve correctly
tofu providers

4. Update State Backend

State files are compatible — no migration needed. Just verify:

# backend.tf — works identically with OpenTofu
terraform {
  backend "s3" {
    bucket         = "mycompany-tfstate"
    key            = "prod/infrastructure.tfstate"
    region         = "us-east-1"
    dynamodb_table = "terraform-locks"
    encrypt        = true
  }
}