cacheman

#!/bin/python
import os
import subprocess
import sys
import tempfile

# Both must be in a format acceptable for rsync
remoteCacheDir = 'xian.matterhorn:/var/cache/pacman/pkg'
localCacheDir = '/var/cache/pacman/pkg'


def transferCache(pacArgs):
    pacProc = subprocess.run(['sudo', 'pacman', '-p', '-q'] + pacArgs,
                             capture_output=True)

    if pacProc.returncode or not pacProc.stdout:
        return

    pkgNames = [fileUrl.split('/')[-1]
                for fileUrl in pacProc.stdout.decode('utf-8').split(os.linesep)
                if fileUrl.startswith('http')]

    if pkgNames:
        print("Attempting to retrieve files from cache {}"
              .format(remoteCacheDir),  end="\n\t")
        print(*pkgNames, sep="\n\t", end="\n\n")

        # Create manifest file
        with tempfile.NamedTemporaryFile('w+') as manifestFile:
            print(*pkgNames, sep=os.linesep,
                  file=manifestFile, flush=True)
            with tempfile.TemporaryDirectory() as tempDir:
                subprocess.run(['rsync', '--progress',
                                '--files-from', manifestFile.name,
                                remoteCacheDir, tempDir])
                subprocess.run(['sudo', 'rsync', '-r',
                                tempDir + os.sep, localCacheDir])


if __name__ == '__main__':
    assert 'sudo' not in sys.argv, 'Run without `sudo`!'

    pacArgs = sys.argv[1:]

    if not pacArgs:
        print('Assuming `pacman -Syu`')
        pacArgs = ['-Syu']

    transferCache(pacArgs)

    subprocess.run(['sudo', 'pacman'] + pacArgs)