Statics are ignored

I don’t believe you need a project.toml.
It can all be contained in the fly.toml itself, but with the right syntax, etc.
Here are two separate links to the doco, specifically the build section related bits.

So it’ll be something like:

[build]
  builder = "paketobuildpacks/builder:base"
  buildpacks = ["gcr.io/paketo-buildpacks/go"]
  [build.args]
    BP_KEEP_FILES = "public/*"

You may need a / or ./ in front of the public/* there.

In the shell output I can not see the build command to validate.

You could do $LOG_LEVEL=debug flyctl deploy ... to get more info on what’s going on.

I can’t see a way to define ENV variable to be used on the builder in the fly.toml

ENV variables are only available for use at run-time, and are setup via fly secrets.
For build-time arguments, the two links above will help.

And you are not allowed to redeploy the builder.

Quoting an answer from an employee:

Are my choices creating a Docker file (go-repo example is 2 years old), or creating my own build pack, that I fully don’t understand?

It appears that using the Dockerfile is what you have to do if you want to serve static files (that you can make available in your final Docker image).

Creating your own buildpack is not necessary, I think.
Just need to pass the build args right.
I hope the above links will help get you going :slight_smile: