Upgrading terraform

expected time	requirements
15 minutes	A computer with Terraform installed, terraform knowledge.

Goal: Learn how to upgrade Terraform.

Explanation

There are a couple of upgrades relevant when using Terraform:

• Terraform itself.
• Providers used in a repository.
• Modules used in a repository.

Terraform

All versions of Terraform can be found on releases.hashicorp.com. Terraform is in the terraform directory.

When jumping versions, please review the upgrade guide. This helps in understanding what changed, and if changes in your repository is required.

Typically you want to upgrade terraform and see if terraform plan still works.

Providers

Providers also have a version. For example the Terraform Google Cloud provider has a version. This version can be found under the purple “USE PROVIDER” button.

You may not specify a version of the provider. That may give unstable results; latest will be used. Although the providers are quite flexible and deprecations usually are communicated well in advance; you can end up in a situation where the old version of the provider you are using will not work anymore.

Typically try to keep the providers up to date. Just as with any software; not updating for a long period of time may cause a difficult upgrade path.

Providers (and modules) can be updated using terraform init -upgrade.

Modules

Very similar to providers; although some modules will not be maintained. These modules may stop working.

Any module has a version. Specifying the version to use makes your root-module more stable, but you may need to modify the version to ensure no deprecations occur.

Modules (and providers) can be updated using terraform init -upgrade.

Howto

Here is an example of version pinning.

terraform {
  required_version = "~> 1.1"
  required_providers {
    aws = {
      version = "~> 2.13.0"
    }
    random = {
      version = ">= 2.1.2"
    }
  }
}

module "vault" {
  source   = "robertdebock/vault/aws"
  version  = "3.0.1"
  variable = "value"
}

The upgrade of Terraform depends a bit on how the installation was done. In case packages are used, simply apt-get update && apt-get upgrade terraform, yum update terraform, and so on.

You can also place a binary in a path that’s in your PATH variable to temporarily try a specific version.