How to use Local execution mode by default (via the terraform workspace command)

Introduction & Use-Case

When working with Terraform Enterprise/Cloud, there are times where you'd like to set your TFE/C Workspace's execution type to "Local". You can set it easily on the UI as explained here [a], but there are times when you'd like to set the Local execution mode by default either programmatically or through the CLI workflow -- that's what this article walks you through.

Procedure

At the time of this writing, there are currently 2 ways to select the local execution mode by default:

- when using the TFE provider [b] OR

- through the data.attributes.execution-mode API setting [c].

The API method is pretty self-explanatory so I'll focus on how to do this using the TFE provider.

Because local workspaces in Terraform (via the terraform workspace command) is a local execution concept only and different from TFE/C workspaces, we have to link them up for a programmatic/CLI-based workflow.

Here are the steps to do so:

1. Add tags to your TFE workspaces using the TFE provider [d] or the API [e]. To learn more about workspace tags, please see [f].

2. Link your working directory to multiple TFE workspaces using workspace tags - via the workspace select command [g] to select which remote workspace to use. The explanation of the principle behind this can be found here [h].

P.S.
If you proceed to use the TFE provider or API to specify local execution modes, please do NOT use/specify the now deprecated operations argument [i] or data.attributes.operations [c] to avoid running into issues.

Link References

[a] https://www.terraform.io/cloud-docs/workspaces/settings#:~:text=to%20disable%20remote%20execution%20for%20a%20workspace%2C%20change%20its%20execution%20mode%20to%20%22local%22

[b] https://registry.terraform.io/providers/hashicorp/tfe/latest/docs/resources/workspace#execution_mode
[c] https://www.terraform.io/cloud-docs/api-docs/workspaces

[d] https://registry.terraform.io/providers/hashicorp/tfe/latest/docs/resources/workspace#tag_names
[e] https://www.terraform.io/cloud-docs/api-docs/workspaces#add-tags-to-a-workspace
[f] https://www.hashicorp.com/blog/new-workspace-tags-for-terraform-cloud
[g] https://www.terraform.io/cli/commands/workspace/select
[h] https://www.terraform.io/cli/workspaces#interactions-with-terraform-cloud-workspaces
[i] https://registry.terraform.io/providers/hashicorp/tfe/latest/docs/resources/workspace#operations