» Terraform Provider Development Program

The Terraform Provider Development Program allows vendors to build Terraform providers that are officially approved and tested by HashiCorp and listed on the official Terraform website. The program is intended to be largely self-serve, with links to information sources, clearly defined steps, and checkpoints.

» What is a Terraform Provider?

Terraform is used to create, manage, and manipulate infrastructure resources. Examples of resources include physical machines, VMs, network switches, containers, etc. Almost any infrastructure noun can be represented as a resource in Terraform.

A provider is responsible for understanding API interactions with the underlying infrastructure like a cloud (AWS, GCP, Azure), a PaaS service (Heroku), a SaaS service (DNSimple, CloudFlare), or on-prem resources (vSphere). It then exposes these as resources users can code to. Terraform presently supports more than 70 providers, a number that has more than doubled in the past 12 months.

All providers integrate into and operate with Terraform exactly the same way. The table below is intended to help users understand who develops, maintains and tests a particular provider.

Provider Engagement Table

» Provider Development Process

The provider development process is divided into six steps below. By following these steps, providers can be developed alongside HashiCorp to ensure new providers are able to be published in Terraform as quickly as possible.

Provider Development Process

  1. Engage: Initial contact between vendor and HashiCorp
  2. Enable: Information and articles to aid with the provider development
  3. Dev/Test: Provider development and test process
  4. Review: HashiCorp code review and acceptance tests (iterative process)
  5. Release: Provider availability and listing on terraform.io
  6. Support: Ongoing maintenance and support of the provider by the vendor.

» 1. Engage

Please begin by providing some basic information about the provider that is being built via a simple webform.

This information is captured upfront and used by HashiCorp to track the provider through various stages. The information is also used to notify the provider developer of any overlapping work, perhaps coming from the community.

Terraform has a large and active community and ecosystem of partners that may have already started working on the same provider. We'll do our best to connect similar parties to avoid duplicate work.

» 2. Enable

We’ve found the provider development to be fairly straightforward and simple when vendors pay close attention and follow to the resources below. Adopting the same structure and coding patterns helps expedite the review and release cycles.

  • Writing custom providers guide
  • How-to build a provider video
  • Sample provider developed by partner
  • Example providers for reference: AWS, OPC
  • Contributing to Terraform guidelines
  • Gitter HashiCorp-Terraform room.

» 3. Development & Test

Terraform providers are written in the Go programming language. The Writing Custom Providers guide is a good resource for developers to begin writing a new provider.

The best approach to building a new provider is to be familiar with both the Writing Custom Providers guide and Extending Terraform section. The guide will give you an introduction in code structure and the basics of authoring a plugin that Terraform can interact with. The Extending Terraform section contains guides, best practices, and API reference for developers writing Terraform plugins. Additionally developers are encouraged to use the AWS provider as an implementation reference. Given the wide surface area of this provider, almost all resource types and preferred code constructs are covered in it.

It is recommended for vendors to first develop support for one or two resources and go through an initial review cycle before developing the code for the remaining resources. This helps catch any issues early on in the process and avoids errors from getting multiplied. In addition, it is advised to follow existing conventions you see in the codebase, and ensure your code is formatted with go fmt.

The provider code should include an acceptance test suite with tests for each individual resource that holistically tests its behavior. The Writing Acceptance Tests section in the Contributing to Terraform document explains how to approach these. It is recommended to randomize the names of the tests as opposed to using unique static names, as that permits us to parallelize the test execution.

Each provider has a section in the Terraform documentation. You'll want to add new index file and individual pages for each resource supported by the provider.

While developing the provider code yourself is certainly possible, you can also choose to leverage one of the following development agencies who’ve developed Terraform providers in the past and are familiar with the requirements and process.

Partner Email Website
Crest Data Systems malhar@crestdatasys.com www.crestdatasys.com
DigitalOnUs hashicorp@digitalonus.com www.digitalonus.com
MustWin bd@mustwin.com www.mustwin.com
OpenCredo hashicorp@opencredo.com www.opencredo.com

» 4. Review

During the review process, HashiCorp will provide feedback on the newly developed provider. Please engage in the review process once one or two sample resources have been developed. Begin the process by emailing terraform-provider-dev@hashicorp.com with a URL to the public GitHub repo containing the code.

HashiCorp will then review the resource code, acceptance tests, and the documentation. When all the feedback has been addressed, support for the remaining resources can continue to be developed, along with the corresponding acceptance tests and documentation.

The vendor is encouraged to send HashiCorp a rough list of resource names that are planned to be worked on along with the mapping to the underlying APIs, if possible. This information can be provided via the webform. It is preferred that the additional resources be developed and submitted as individual PRs in GitHub as that simplifies the review process.

Once the provider has been completed another email should be sent to terraform-provider-dev@hashicorp.com along with a URL to the public GitHub repo containing the code requesting the final code review. HashiCorp will review the code and provide feedback about any changes that may be required. This is often an iterative process and can take some time to get done.

The vendor is also required to provide access credentials for the infrastructure (cloud or other) that is managed by the provider. Please encrypt the credentials using our public GPG key published at keybase.io/terraform (you can use the form at https://keybase.io/encrypt#terraform) and paste the encrypted message into the webform. Please do NOT enter plain-text credentials. These credentials are used during the review phase, as well as to test the provider as part of the regular testing HashiCorp conducts.

» 5. Release

At this stage, it is expected that the provider is fully developed, all tests and documentation are in place,the acceptance tests are all passing, and that HashiCorp has reviewed the provider.

HashiCorp will create a new GitHub repo under the terraform-providers GitHub organization for the new provider (example: terraform-providers/terraform-provider-NAME) and grant the owner of the original provider code write access to the new repo. A GitHub Pull Request should be created against this new repo with the provider code that had been reviewed in step-4 above. Once this is done HashiCorp will review and merge the PR, and get the new provider listed on terraform.io. This is also when the provider acceptance tests are added to the HashiCorp test harness (TeamCity) and tested at regular intervals.

Vendors whose providers are listed on terraform.io are permitted to use the HashiCorp Tested logo for their provider.

» 6. Support

Many vendors view the release step to be the end of the journey, while at HashiCorp we view it to be the start. Getting the provider built is just the first step in enabling users to use it against the infrastructure. Once this is done on-going effort is required to maintain the provider and address any issues in a timely manner.

The expectation is to resolve all critical issues within 48 hours and all other issues within 5 business days. HashiCorp Terraform has as extremely wide community of users and contributors and we encourage everyone to report issues however small, as well as help resolve them when possible.

Vendors who choose to not support their provider and prefer to make it a community supported provider will not be listed on terraform.io.

» Checklist

Below is an ordered checklist of steps that should be followed during the provider development process. This just reiterates the steps already documented in the section above.

  • Fill out provider development program engagement webform

  • Refer to the example providers and model the new provider based on that

  • Create the new provider with one or two sample resources along with acceptance tests and documentation

  • Send email to terraform-provider-dev@hashicorp.com to schedule an initial review

  • Address review feedback and develop support for the other resources

  • Send email to terraform-provider-dev@hashicorp.com along with a pointer to the public GitHub repo containing the final code

  • Provide HashiCorp with credentials for underlying infrastructure managed by the new provider via the webform

  • Address all review feedback, ensure that each resource has a corresponding acceptance test, and the documentation is complete

  • Create a PR for the provider against the HashiCorp provided empty repo.

  • Plan to continue supporting the provider with additional functionality as well as addressing any open issues.

» Contact Us

For any questions or feedback please contact us at terraform-provider-dev@hashicorp.com.