generate.py

import sys
import os

from yaml import load, BaseLoader

from jinja2 import FileSystemLoader, Environment, select_autoescape

def usage() -> str:
    return """Usage: <context> <compose> <version>
context: path to the context
compose: output path for the compose file
version: the version used to tag the images
    """

if len(sys.argv) != 4:
    print(usage())
    exit(1)

context = sys.argv[1]
if not os.path.exists(context) or not os.path.isfile(context):
    print("Context file not found.")
    exit(1)
compose = sys.argv[2]
version = sys.argv[3]
version = "latest" if version == "master" else version

env = Environment(loader=FileSystemLoader("."), autoescape=select_autoescape(), trim_blocks=True, lstrip_blocks=True)
template = env.get_template("compose.tmpl")

with open(context, "r") as fd:
    context = load(fd, BaseLoader)
context['version'] = version

with open(compose, "w") as fd:
    fd.write(template.render(context))