fix: Associate spot instances with their instance IDs for auth (#3383)

Fixes #2162.

provisioner/terraform/resources.go

@@ -310,6 +310,7 @@ func applyAutomaticInstanceID(resource *tfjson.StateResource, agents []*proto.Ag
 	key, isValid := map[string]string{
 		"google_compute_instance":         "instance_id",
 		"aws_instance":                    "id",
+		"aws_spot_instance_request":       "spot_instance_id",
 		"azurerm_linux_virtual_machine":   "virtual_machine_id",
 		"azurerm_windows_virtual_machine": "virtual_machine_id",
 	}[resource.Type]

provisioner/terraform/resources_test.go

@@ -219,6 +219,10 @@ func TestInstanceIDAssociation(t *testing.T) {
 		Auth:          "aws-instance-identity",
 		ResourceType:  "aws_instance",
 		InstanceIDKey: "id",
+	}, {
+		Auth:          "aws-instance-identity",
+		ResourceType:  "aws_spot_instance_request",
+		InstanceIDKey: "spot_instance_id",
 	}, {
 		Auth:          "azure-instance-identity",
 		ResourceType:  "azurerm_linux_virtual_machine",