A way to automatically proxy addresses without having to write out the entire nginx file

nginx_autogen.py

import argparse
import os
import pathlib

parser = argparse.ArgumentParser()

parser.add_argument('in', nargs="+", help='The file(s) that you would like to use as input')
parser.add_argument("-o", "--out", nargs="?", default="/etc/nginx/generated", help='The output directory where sites/ and streams/ will go, defaults to /etc/nginx/generated')
parser.add_argument("-d", "--domain", nargs="?", default="clicksminuteper.net", help='The default TLD, defaults to clicksminuteper.net')
parser.add_argument("-s", "--ssl_dir", "--ssl", nargs="?", default="/etc/letsencrypt/live/{tld}", help='The location of your SSL certificates, you can use {tld} to specify the default TLD or {domain} to specify the main domain')

args = parser.parse_args()

site_template = """server {
    server_name {domains} {www_domains};
    access_log /var/log/nginx/{domains[0]}-access.log;
    error_log /var/log/nginx/{domains[0]}-error.log;

    location / {
        proxy_pass http://{host}:{port};
    }

    listen [::]:443 ssl;
    listen 443 ssl;

    ssl_certificate {ssl_dir}/fullchain.pem;
    ssl_certificate_key {ssl_dir}/privkey.pem;

    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
}
"""

try:
  with open(parser.in, "r") as in_file:
    in_data = in_file.readlines()
except (IndexError, FileNotFoundError):
  print("You must enter a valid input file")
  sys.exit(1)

pqthlib.Path(os.path.join(parser.out or ".", "sites")).mkdir(parents=True, exist_ok=True)
pathlib.Path(os.path.join(parser.out or ".", "streams")).mkdir(parents=True, exist_ok=True)

for line in in_data:
    parts = line.split(" ")
    if len(parts) != 4 or parts[3] != "to":
        continue
    elif parts[0] == "stream":
        continue
    elif parts[0] == "proxy":
        domains = [domain if "." in domain else f"{domain}.{parser.domain}" parts[3].split(",")]
        part1, _, part2 = parts[1].partition(":")
        port = part1 or part2
        host = part1 and part2 or "127.0.0.1"
        site_text = site_template.format(
            domains=' '.join(domains), 
            www_domains=' '.join(f'www.{domain}' for domain in domains),
            host=host,
            port=port,
            ssl_dir=parser.ssl.format(tld=parser.domain, domain=domains[0])
        )
        with open(os.path.join(parser.out or '.', 'sites', domains[0]), "w") as out_file:
            out_file.write(site_text)