check-git

#!/usr/bin/env python

# Looks at the local git working copy and determines…
# - Whether this is a release branch: creates `release_build` (empty) if it is
# - What tag should be assigned to the build: creates `build_tag` containing the tag

from operator import contains
import re
import subprocess
import os
import os.path

def write(name, str):
    f = open(name, 'w')
    f.write(str)
    f.close()

def clean_files():
    for name in ['release_build', 'build_tag']:
        if os.path.isfile(name):
            os.remove(name)

# '1.1.3-4-g2c1a80f'
git_describe = subprocess.check_output('git describe --tags',
    shell=True).decode("utf-8").rstrip()
# 'master', 'HEAD', ...
git_branch = subprocess.check_output('git rev-parse --abbrev-ref HEAD',
    shell=True).decode("utf-8").rstrip()

print(git_describe)
print(git_branch)

# We either a) are @ a tag, in which case we have a release build under us
#   b) are somewhere post a tag, in which case no release must be made

clean_files()

# Might this be a release branch/tag? If so, touch the file `release_build`
possible_release_branch = contains(['master', 'HEAD'], git_branch)

if re.match('^\d{1,}\.\d{1,}\.\d{1,}$', git_describe) and possible_release_branch:
    write('release_build', '')

write('build_tag', git_describe)