check.py

#!/usr/bin/python3
#
# Find all Butane configs in the doc tree, use the podman Butane container
# to run them through butane --strict, and fail on any errors.
#
# A Butane config looks like this:
#
# [source,yaml]
# ----
# variant:[...]
# ----
#
# If variant: is missing, we print a warning but continue, since there
# might be [source,yaml] documents that aren't Butane configs.

import argparse
import os
import re
import subprocess
import sys
import textwrap

ERR = '\x1b[1;31m'
WARN = '\x1b[1;33m'
RESET = '\x1b[0m'

container = os.getenv('BUTANE_CONTAINER', 'quay.io/coreos/butane:release')
matcher = re.compile(r'^\[source,\s*yaml\]\n----\n(.+?\n)----$',
        re.MULTILINE | re.DOTALL)

parser = argparse.ArgumentParser(description='Run validations on docs.')
parser.add_argument('-v', '--verbose', action='store_true',
                    help='log all detected Butane configs')
args = parser.parse_args()

def handle_error(e):
    raise e

ret = 0
for dirpath, dirnames, filenames in os.walk('.', onerror=handle_error):
    dirnames.sort()  # walk in sorted order
    for filename in sorted(filenames):
        filepath = os.path.join(dirpath, filename)
        if not filename.endswith('.adoc'):
            continue
        with open(filepath) as fh:
            filedata = fh.read()
        # Iterate over YAML source blocks
        for match in matcher.finditer(filedata):
            bu = match.group(1)
            buline = filedata.count('\n', 0, match.start(1)) + 1
            if not bu.startswith('variant:'):
                print(f'{WARN}Ignoring non-Butane YAML at {filepath}:{buline}{RESET}')
                continue
            if args.verbose:
                print(f'Checking Butane config at {filepath}:{buline}')
            result = subprocess.run(
                    ['podman', 'run', '--rm', '-i', container, '--strict'],
                    universal_newlines=True, # can be spelled "text" on >= 3.7
                    input=bu,
                    stdout=subprocess.DEVNULL,
                    stderr=subprocess.PIPE)
            if result.returncode != 0:
                formatted = textwrap.indent(result.stderr.strip(), '  ')
                # Not necessary for ANSI terminals, but required by GitHub's
                # log renderer
                formatted = ERR + formatted.replace('\n', '\n' + ERR)
                print(f'{ERR}Invalid Butane config at {filepath}:{buline}:\n{formatted}{RESET}')
                ret = 1
sys.exit(ret)