How is the buildx TUI implememtned?

guysoft · March 24, 2024, 2:03pm

Hey,
I was thinking of making a similar UI for CustomPiOS that I build and maintain, that has the build output that buildx has (I need to re-implement it in python):

I was wondering, how is this implemented?

I thought it would be somewhere around here:

But I can’t see where it would send the special chars to the terminal to go up lines, etc.

Any chance someone here could point me to the location?

rimelek · March 24, 2024, 5:03pm

Since it is written in GO and you want Python, you should search for “overwrite the same line in python”. A simple bash solution:

And a python

guysoft · March 25, 2024, 10:05am

Its not only the return carriage. Its going up and updating at least 3 different sections. I would like to see the code itself because it might have some design insight too.

I can read go to see what was done.

rimelek · March 25, 2024, 4:11pm

If you want to see the source code, you could clone buildkit (GitHub - moby/buildkit: concurrent, cache-efficient, and Dockerfile-agnostic builder toolkit) and search for some texts seen in the progress to get closer where builtkit writes to the terminal.

That progress info is generated by buildkit.

github.com

moby/buildkit/blob/da0131c1c753b88cd29bd0c6ab93e1d2de46785e/frontend/dockerui/config.go#L311


      
          
          	var src *llb.State
          
          	if !bctx.forceLocalDockerfile {
          		if bctx.dockerfile != nil {
          			src = bctx.dockerfile
          		}
          	}
          
          	if src == nil {
          		name := "load build definition from " + bctx.filename
          
          		filenames := []string{bctx.filename, bctx.filename + ".dockerignore"}
          
          		// dockerfile is also supported casing moby/moby#10858
          		if path.Base(bctx.filename) == DefaultDockerfileName {
          			filenames = append(filenames, path.Join(path.Dir(bctx.filename), strings.ToLower(DefaultDockerfileName)))
          		}
          
          		opts = append([]llb.LocalOption{
          			llb.FollowPaths(filenames),

I didn1t try to find whre it writes the terminal, but if I had to implement a feature like this, I would probably write calculate the size of the terminal, store the lines, calculate the available lines remained after the finished layers, and write the end of the list to the remaining lines in a loop. If you find the exact code that implements it, please, share it si we can learn from it too.