This example doesn't specify a credential and a project intentionally.
$ gcloud auth application-default login
# replace 【YOUR PROJECT】 with your project
# e.g.
# export GOOGLE_PROJECT=terraform-toshi0607
$ export GOOGLE_PROJECT=【YOUR PROJECT】
$ terraform init
$ terraform plan
# If you want to apply this google_compute_instance resource with node_affinities, you need sole tenant.
# See https://cloud.google.com/compute/docs/nodes/provisioning-sole-tenant-vms