update-dockerfile-includes

#!/usr/bin/python

import os
import re
from subprocess import check_call as sh
import sys

ROOT = os.path.dirname(os.path.abspath(__file__))
STACKS = os.path.join(ROOT, 'docker-stacks')
STACK_URL = 'https://github.com/jupyter/docker-stacks'
DOCKERFILE = os.path.join(ROOT, 'Dockerfile')

def clone_stacks(ref):
    if not os.path.exists(STACKS):
        sh(['git', 'clone', STACK_URL, STACKS], cwd=ROOT)
    else:
        sh(['git', 'fetch', 'origin'], cwd=STACKS)
    sh(['git', 'checkout', ref], cwd=STACKS)

def read_stack(name):
    """Yield lines from a docker-stack Dockerfile.
    
    Comments-out FROM, MAINTAINER
    """
    dockerfile = os.path.join(STACKS, name, 'Dockerfile')
    with open(dockerfile) as f:
        # read up to FROM
        for line in f:
            if line.startswith(('FROM', 'MAINTAINER')):
                line = '# ' + line
            yield line

begin_include_re = re.compile(r'\s*#\s*BEGININCLUDE\s+jupyter/(.*)')
def update_dockerfile(ref):
    clone_stacks(ref)
    lines = []
    with open(DOCKERFILE) as f:
        line = True
        while line:
            line = f.readline()
            if line.startswith('FROM '):
                break
            lines.append(line)
        # FROM:
        from_, tag = line.split(':')
        lines.append('%s:%s\n' % (from_, ref))
        
        while line:
            line = f.readline()
            lines.append(line)
            include_match = begin_include_re.match(line)
            if include_match:
                # read include
                name = include_match.group(1)
                print("including %s:%s" % (name, ref))
                lines.extend(read_stack(name))
                # strip between begin/end
                endline = ''
                while 'ENDINCLUDE' not in endline:
                    endline = f.readline()
                lines.append(endline)

    # write out result
    with open(DOCKERFILE, 'w') as f:
        for line in lines:
            f.write(line)

if __name__ == '__main__':
    update_dockerfile(sys.argv[1])