...assuming you think it's "phenomenal" to use Packer to build a Digital Ocean image.

Save your token to file (do once)

echo <your-digitalocean-api-token-for-devbox> > ~/.digitalocean-api-token-devbox
sudo chown root ~/.digitalocean-api-token-devbox
sudo chmod 600 ~/.digitalocean-api-token-devbox

Set API token environment variable (once per shell you want to run packer from)

. load-token

Test and build

./build

Then go to DigitalOcean and create a droplet from the image.