Developer Environment Setup

Set up a local environment for Harness Template Library development using either the DevContainer or the container-based Makefile workflow.

Developing for the Harness Template Library (HTL) requires a local environment with Docker, Terraform or OpenTofu, and Git installed. Choose either the DevContainer or the local container-based Makefile workflow described below to get set up.

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Before you begin

• Container engine: A supported version of Docker or a Docker-compatible engine.

• Git: Git installed locally so you can clone the Harness Template Library repository.

• Terraform or OpenTofu: Required for template development. Both DevContainer and Makefile workflows supply these inside the container, so a local install is optional.

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Use the DevContainer in this repository

This repository includes support for DevContainers. To install this into your environment, you need the following:

• A supported version of Docker or a Docker-compatible engine

• The DevContainers extension for VS Code, or a compatible extension for your IDE

Once your development environment is ready, clone this repository into your IDE. For VS Code installations, you are prompted to reopen the workspace in a new container.

To modify the DevContainer, edit the devcontainer.json file at the root of this repository, then reload.

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Local container-based development

A robust Makefile configuration is included within this repository. The command file contains frequently used shortcuts and commands. To use this solution, you need the following:

• A supported version of Docker or a Docker-compatible engine

• Make installed for your OS: Windows, or Mac with Xcode command line tools installed or with Homebrew GNU Make

Go to Local Testing Using Make to review the testing workflow in detail.

To get the current list of available commands, enter make help in a Terminal session in this directory:

debug            Loads the current directory into the container to allow running commands locally
init             Executes Terraform/Tofu `init`. Pass `migrate` to delete any local `backed.tf` and a `-migrate-state` will be performed.
plan             Executes a Terraform/Tofu `plan`
plan_output      Executes a Terraform/Tofu `plan`
plan_show        Executes a Terraform/Tofu `plan`
apply            Automatically runs a Terraform/Tofu `apply`
destroy          Automatically runs a Terraform/Tofu `destroy`
refresh          Refreshes the statefile
output           Display the Terraform/Tofu outputs | To return a single output, pass `RESOURCE=<terraform-output-name>`
fmt              Formats the Terraform files in the current directory
fmt_all          Formats all Terraform files in the entire repository
testing_cleanup  Removes the local `.terraform` and `.terraform.lock.hcl` files.
cycle            Idempotency Check. Runs the commands - init, destroy, apply, and plan
teardown         Full Suite Cleanup.  Runs the commands - destroy and testing_cleanup
all              End-to-end testing. Runs the commands - init, fmt, plan, apply, destroy, testing_cleanup
version_tests    Runs an entire suite of executions for a template based on the chose type. Supported types: terraform or tofu - e.g `type=tofu`
full_suite       Cycles a full End-to-end testing for all versions listed. Reads all versions in the .terraform_verions and .tofu_versions files.
generate         Generate a new directory using a template type. The argument `name=<new-template-name>` needs to be passed along with this command

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Next steps

Your local environment is ready for Harness Template Library development. Continue with the following:

• Local Testing Using Make: Run the full test suite against your templates locally.

• Using mise: Manage Terraform and OpenTofu tool versions consistently.

• Create a new template in a custom HTL: Build your first template once your environment is set up.