Terraform

Terraform is used to manage our infrastructure in the cloud. We use completely different terraform code for each cloud provider, under terraform/<cloud-provider>. This is much simpler than trying to abstract them away into a ‘lowest common denominator’ set of modules.

The source files for each provider we currently deploy with terraform are under a specific directory under terraform/ in our infrastructure repo.

Each provider directory also has a projects subdirectory where variables defining each cluster are stored.

State and Backends

Terraform stores state to reflect the current state of the infrastructure managed, so it can figure out what changes need to happen and how to make them happen. This state has to be stored somewhere, and we store it in a Google Cloud Storage Bucket by default. The configuration is specified directly in main.tf for each cloud provider.

In some cases, we may want to store the state in a different place, primarily so that communities can run terraform apply themselves without being given access to every community’s terraform state. See the documentation for community partners for more details.

Backend Initialization

To initialize the backends, you need to run terraform init command from within the directory where the source files of the specific provider you want to access are.

Example:

cd terraform/azure
terraform init

Note

If prior backend data exists in a terraform.lock.hcl, you might see an Error: Backend configuration changed when trying to initialize that backend. To reconfigure this backend, ignoring any saved configuration, add the -reconfigure flag to the init command.

If you’re trying to work on a project that has state stored elsewhere, follow the docs here

Workspaces

We use terraform workspaces to maintain separate terraform states about different clusters we manage. There should be one workspace per cluster, with the same name as the .tfvars file with variable definitions for that cluster.

Note

Workspaces are defined per backend. If you can’t find the workspace you’re looking for, double check you’ve initialized the correct backend.

How to change Terraform workspaces

If the new workspace is stored in the same backend as the current workspace

If you want to change to a different terraform workspace that is stored in the same backend that you initialised with, you can simply run:

terraform workspace select WORKSPACE_NAME

Note

We recently renamed the pilot-hubs repository to infrastructure, however we have not yet renamed the Terraform projects, so they are still named pilot-hubs!

For example, if you were working in the pilot-hubs workspace but want to change to justiceinnovationlab, these are both stored in the same backend and so the command looks like:

terraform workspace select justiceinnovationlab

Note

For the majority of day-to-day work, this will be the prevalent workflow provided you have initialised terraform with

terraform init