If you don't have an account with fly.io, you can sign up here.
Then install the flyctl tool following the instructions here.
Create a Dockerfile:
FROM ghcr.io/getzola/zola:v0.17.2 AS builder
WORKDIR /app
COPY . .
RUN ["zola", "build"]
FROM joseluisq/static-web-server:2
COPY --from=builder /app/public /public
ENV SERVER_PORT 8080
You can now run fly launch. It will detect the Dockerfile and mostly auto-configure everything. Fill out the necessary information, but say "no" to (1) launching any databases and (2) deploying immediately.
Take note of the hostname assigned to your app.
If you already have a Zola site you must now ensure that base_url in config.toml is set correctly using the hostname from your app (or whatever domain you have pointing to the app):
base_url = "https://white-snow-9922.fly.dev"
If you don't have an existing site, initialize one with zola init -f and remember to set the correct base_url.
You're now ready to launch your site! Run flyctl deploy and have fun!
Finally, to set up continuous deployment of your site from GitHub, follow this guide, steps 4-8. Any changes to your site will now be pushed automatically.