apk-progress-fd.py

import subprocess

def install_package(package):
    percent = 0
    # Alpine apk provides machine-readable progress in bytes_downloaded/bytes_total format output to file descriptor of choice, so create a pipe for it
    pipe_rfd, pipe_wfd = os.pipe()
    with os.fdopen(pipe_rfd) as pipe_rf:
        with subprocess.Popen(['apk', '--progress-fd', str(pipe_wfd), '--no-cache', 'add', package], pass_fds=[pipe_wfd]) as p:
            # Close write pipe for vmmgr to not block the pipe once apk finishes
            os.close(pipe_wfd)
            while p.poll() == None:
                # Wait for line end or EOF in read pipe and process it
                data = pipe_rf.readline()
                if data:
                    progress = data.rstrip().split('/')
                    percent = math.floor(int(progress[0]) / int(progress[1]) * 100)
            # If the apk command didn't finish with returncode 0, raise an exception
            if p.returncode:
                raise subprocess.CalledProcessError(p.returncode, p.args)