First, from a source checkout of the Talos repository, create the GCP compatible image:

make image-gcloud

Upload the image to GCP with:

gsutil cp /path/to/talos/build/gcloud/talos.tar.gz gs://<gcloud bucket name>

Create a custom GCP image with:

gcloud compute images create talos \
  --source-uri=gs://<gcloud bucket name>/talos.tar.gz \

Create an instance in GCP, making sure to create a user-data key in the “Metadata” section, with a value of your full Talos node configuration.

Note: Further exploration is needed to see if we can use the “Startup script” section instead.