Prebuild invalidation

[SasSwart]

Prebuilt workspaces will become stale if not claimed. Examples:

• A monorepo cloned during prebuild will fall behind its origin
• A new VM AMI or container image may release after a workspace was created

When defining a prebuild, the following syntax should configure a maximum lifetime for a prebuild, after which such an unclaimed prebuild must be deleted and replaced.

resource "coder_workspace_preset" "us-nix" {
  name = "Nix US"
  
  parameters = {
    (data.coder_parameter.region.name)     = "us-pittsburgh"
    (data.coder_parameter.image_type.name) = "codercom/oss-dogfood-nix:latest"
  }
  
  # ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
  prebuilds = {
	  instances = 2
	  cache_invalidation = {
		  # See the Invalidation section for more
		  invalidate_after_secs = 86400
	  }
	  autoscaling = {
		  ... # See the Autoscaling section for examples
	  }
  }
}

Furthermore, it should be possible to invalidate a prebuild using the API. This might already be possible by using the endpoint that deletes a workspace.

[SasSwart]

Furthermore, it should be possible to invalidate a prebuild using the API. This might already be possible by using the endpoint that deletes a workspace.

Initially, we considered manual prebuilt workspace invalidation only within the context of them becoming stale. However, invalidating a prebuilt workspace is mechanically no different from deleting it.

We've also received feedback to the effect that template administrators should be able to delete prebuilt workspaces for maintenance reasons.

As a result, it is clear that we should provide template administrators with:

• the ability to delete a prebuilt workspace
  • this allows them to appropriately handle stale builds
  • as well as to clean up failed builds
  • this would look and feel identical to deleting any other workspace
• the ability to bulk delete all unclaimed prebuilt workspaces for a given preset or template version
• template administrators should not be able to delete workspaces for any other users, except for the prebuilds system user