OpenTofu

Create an OpenTofu workspace and provision infrastructure with Harness IaCM.

OpenTofu is an open-source infrastructure-as-code tool, and Harness Infrastructure as Code Management (IaCM) runs your OpenTofu workspaces and pipelines with Git-backed configuration, connectors, and optional cost estimation.

This guide walks you from connectors and workspace creation through a standard provision pipeline (init, plan, apply) and an optional approval between plan and apply.

What will you learn?

This guide covers the following:

• Connectors and workspace: Create cloud and Git connectors, then create an OpenTofu workspace wired to your repository and OpenTofu version.

• Provision pipeline: Generate or author a pipeline that runs init, plan, and apply for your workspace.

• Approvals: Optionally gate apply behind an approval step.

Before you begin

Before you use this guide, ensure you have the following:

• Harness account with IaCM enabled: You need Infrastructure as Code Management under Infrastructure in Harness when it is entitled on your account. Go to Getting started with Harness Platform to access or create a Harness account.

  CONTACT HARNESS SUPPORT

  If IaCM does not appear, go to Get started with IaCM, or contact your account administrator or Harness Support.

• Pipeline permissions: View, Create/Edit, and Execute on Pipelines. Go to RBAC in Harness to review the permissions model, and go to Manage roles to assign a role that includes them.

• Git repository: Access to a Git provider with your OpenTofu project.

• Cloud provider: Access to a cloud provider such as AWS or Google Cloud Platform for the infrastructure you manage.

• Harness organization and project: An organization and project set up on the Harness Platform.

Sample OpenTofu

The following example OpenTofu (.tf) file declares:

• Provider Configuration: Specifies the AWS provider and sets the region to "us-east-1". Go to AWS Regions & Availability Zones for a complete region list.

• Resource Definition: Creates an EC2 instance with the identifier my_first_ec2_instance.

• AMI: Utilizes ami-123abc321cba18, go to AWS EC2 User Guide to find your AMI image ID.

• Instance Type: Configures the instance to use a t2.micro. Go to the AWS t2 instances list. Tags: To facilitate easy identification and management within AWS resources, a tag name with the value my_first_ec2_instance is applied.

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

resource "aws_instance" "my_first_ec2_instance" {
  ami = "ami-123abc321cba18"
  instance_type = "t2.micro" # Go to https://aws.amazon.com/ec2/instance-types/t2/ for a full T2 instance type list.

  tags = {
    Name = "my_first_ec2_instance"
  }
}

Go to OpenTofu Documentation to review currently supported workspace types.

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Set up your workspace

A workspace is a named environment for storing your OpenTofu configurations and resources. Connect your cloud provider and code repository through Connectors to manage infrastructure changes and updates with Harness IaCM pipelines.

Harness recommends configuring your connector before creating your workspace, however, you can also add new connectors during the Create Workspace flow.

Step 1: create a connector

Use Harness AI to create and configure your cloud provider and code repository connectors before you create a workspace:

Create a Connector

Create Cloud Provider Connector with Harness AI

Step-by-step

When adding any connector, start by:

1. Sign in to app.harness.io.

2. In the module pane, select Infrastructure.

3. Select Project Setup, and then select Connectors.

4. Select New Connector (AI).

5. Select an option, for example "Create a GitHub connector", or type your request to create a connector for your chosen cloud provider or code repository.

Harness creates a YAML file for your connector. Once you select Create, Harness creates your connector and adds it to your project.

EDIT CONNECTOR

Edit your connector by updating the AI generated YAML file, or by selecting Edit Details in the connectors panel.

Go to Connect your Cloud Provider and Connect your Code Repository to connect your cloud provider and code repository.

OIDC CONNECTORS

For easier access and token management, use the OIDC (OpenID Connect) option in the Credentials panel. This allows your connector to assume roles with permissions set in your Cloud Provider, updated only by authorized users. Go to the Use OIDC tab for setup details.

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Step 2: create your workspace

Once you have configured your connectors, you can create a workspace and select them in the New Workspace panel:

MIGRATE EXISTING PROJECTS

For first-time use, go to State Migration to import the state of your existing Terraform projects into a Harness workspace.

Interactive Guide

Create an OpenTofu Workspace in Harness IaCM

Step-by-step

1. In the module pane, select Infrastructure.

2. Select an existing project or create a new project.

3. Select Workspaces, and then select New Workspace.

4. Select Create new Workspace, then select Start from scratch and complete the following fields in the new workspace wizard:

About workspace

• Name - Enter a unique name to identify the workspace.

• Description (optional): Enter an optional description to help identify the workspace.

• Tags (optional): Add a unique tag to identify the workspace.

Configure repository details

• Select your Git provider, either Harness Code Repository or Third-party Git provider for other providers like GitHub or GitLab.

• Git Connector: Select the Git connector you created in the previous step.

• Git Fetch Type: Select the Git fetch type, either Latest from branch, Git tag or Commit SHA.

• Git Branch: Specify the branch you want to use for the workspace.

BRANCH WITH JEXL

You can configure the workspace branch as a JEXL expression that references a pipeline variable, and then set the pipeline variable as a runtime input.

Set your branch variable as a runtime input in the pipeline:

variables:
 - name: iacm_branch
   type: String
   description: ""
   required: true
   value: <+input>.default(main)

• Folder Path: Specify the folder path to the OpenTofu configuration files in the repository.

Advanced options allow you to include submodules if your code repository includes modules and submodules. Go to Module Registry to review module registry concepts.

Provisioner

• Connector: Select the cloud provider connector you created in the previous step.

• Cloud Cost Estimation: Toggle the Enable Cost Estimation switch to enable cloud cost estimation. This lets you estimate the cost of your infrastructure changes before you apply them.

• Workspace Type: Select OpenTofu as the workspace type you want to use for the workspace.

• OpenTofu Version: Select the OpenTofu version you want to use for the workspace

Add variable set (optional)

If you have configured variable sets for reuse, select the variable set you want to use for the workspace.

1. Select Create.

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Step 3: add a provision pipeline

A pipeline structures workflows to manage tasks like planning infrastructure changes, enforcing policies, and approvals. Go to Harness Pipelines to review pipeline concepts. You can also add pipelines through the Harness Platform or use a code-first approach with YAML.

Harness AI pipeline generation

Interactive Guide

Create a Provision Pipeline in Harness IaCM

Step-by-step

Start by adding the pipeline:

1. Select the Infrastructure module.

2. Select Pipelines, then select Create a Pipeline.

3. Select an option from Harness AI chat or type a request to generate one, for example:

   • "Create a pipeline to Provision an OpenTofu files with an init, plan and apply step."

4. Review the generated YAML and Harness AI chat summary, and make any changes if necessary.

5. Select Accept.

The Provision operation adds three Terraform plugin steps: init, plan, and apply. Go to Tofu/Terraform Plugins to review supported OpenTofu/Terraform commands.

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Step 4: run your pipeline

Now run your pipeline to provision your infrastructure.

To run your provision pipeline, do the following:

1. Click Save to save your pipeline.

2. Click Run in the top right corner.

3. Confirm any runtime inputs if prompted.

4. Click Run Pipeline.

The pipeline executes the three steps in order: init, plan, and apply. Each step shows progress in real time. Click any step to view detailed logs.

After the apply step completes successfully, your infrastructure is provisioned. Go to the Workspaces view, select your workspace, and open the Resources tab to see the resources created.

ADD PRODUCTION FEATURES

Go to Set Up OpenTofu Provisioner to add approval gates, cost estimation, and variable management to your provisioner.