old_contents: #!/usr/bin/python
  
  import jinja2
  import os
  
  convert = lambda src, dst, args: open(dst, "w").write(jinja2.Template(open(src).read()).render(**args))
  
  args = os.environ.copy()
  
  # Get the first DNS server
  with open("/etc/resolv.conf") as handle:
      content = handle.read().split()
      args["RESOLVER"] = content[content.index("nameserver") + 1]
  
  if "HOST_WEBMAIL" not in args:
      args["HOST_WEBMAIL"] = "webmail"
  if "HOST_ADMIN" not in args:
      args["HOST_ADMIN"] = "admin"
  if "HOST_WEBDAV" not in args:
      args["HOST_WEBDAV"] = "webdav:5232"
  if "HOST_ANTISPAM" not in args:
      args["HOST_ANTISPAM"] = "antispam:11334"
  
  # TLS configuration
  cert_name = os.getenv("TLS_CERT_FILENAME", default="cert.pem")
  keypair_name = os.getenv("TLS_KEYPAIR_FILENAME", default="key.pem")
  args["TLS"] = {
      "cert": ("/certs/%s" % cert_name, "/certs/%s" % keypair_name),
      "letsencrypt": ("/certs/letsencrypt/live/mailu/fullchain.pem",
          "/certs/letsencrypt/live/mailu/privkey.pem"),
      "mail": ("/certs/%s" % cert_name, "/certs/%s" % keypair_name),
      "mail-letsencrypt": ("/certs/letsencrypt/live/mailu/fullchain.pem",
          "/certs/letsencrypt/live/mailu/privkey.pem"),
      "notls": None
  }[args["TLS_FLAVOR"]]
  
  if args["TLS"] and not all(os.path.exists(file_path) for file_path in args["TLS"]):
      print("Missing cert or key file, disabling TLS")
      args["TLS_ERROR"] = "yes"
  
  # Build final configuration paths
  convert("/conf/tls.conf", "/etc/nginx/tls.conf", args)
  convert("/conf/proxy.conf", "/etc/nginx/proxy.conf", args)
  convert("/conf/nginx.conf", "/etc/nginx/nginx.conf", args)
  if os.path.exists("/var/log/nginx.pid"):
      os.system("nginx -s reload")
  
new_contents: #!/usr/bin/python
  
  import jinja2
  import os
  
  convert = lambda src, dst, args: open(dst, "w").write(jinja2.Template(open(src).read()).render(**args))
  
  args = os.environ.copy()
  
  # Get the first DNS server
  with open("/etc/resolv.conf") as handle:
      content = handle.read().split()
      args["RESOLVER"] = content[content.index("nameserver") + 1]
  
  if "HOST_WEBMAIL" not in args:
      args["HOST_WEBMAIL"] = "webmail"
  if "HOST_ADMIN" not in args:
      args["HOST_ADMIN"] = "admin"
  if "HOST_WEBDAV" not in args:
      args["HOST_WEBDAV"] = "webdav:5232"
  if "HOST_ANTISPAM" not in args:
      args["HOST_ANTISPAM"] = "antispam:11334"
  
  # TLS configuration
  cert_name = os.getenv("TLS_CERT_FILENAME", default="cert.pem")
  keypair_name = os.getenv("TLS_KEYPAIR_FILENAME", default="key.pem")
  args["TLS"] = {
      "cert": ("/certs/%s" % cert_name, "/certs/%s" % keypair_name),
      "letsencrypt": ("/certs/letsencrypt/live/mailu/fullchain.pem",
          "/certs/letsencrypt/live/mailu/privkey.pem"),
      "mail": ("/certs/%s" % cert_name, "/certs/%s" % keypair_name),
      "mail-letsencrypt": ("/certs/letsencrypt/live/mailu/fullchain.pem",
          "/certs/letsencrypt/live/mailu/privkey.pem"),
      "notls": None
  }[args["TLS_FLAVOR"]]
  
  if args["TLS"] and not all(os.path.exists(file_path) for file_path in args["TLS"]):
      print("Missing cert or key file, disabling TLS")
      args["TLS_ERROR"] = "yes"
  
  # Build final configuration paths
  convert("/conf/tls.conf", "/etc/nginx/tls.conf", args)
  convert("/conf/proxy.conf", "/etc/nginx/proxy.conf", args)
  convert("/conf/nginx.conf", "/etc/nginx/nginx.conf", args)
  if os.path.exists("/var/run/nginx.pid"):
      os.system("nginx -s reload")
  
subject: Update config.py