fix_env_file.py

#!/usr/bin/env python3
import sys
import os
import datetime

"""
Script to update an environment file based on a template
Inspired by: https://github.com/Rillke/Docker-env-file-update/blob/master/update-env.sh
"""

def extract_key_value(line: str) -> tuple[str, str]:
    key, value = line.split('=', 1)
    return key, value.strip()

def get_user_input(prompt: str, default: str) -> str:
    user_input = input(f"{prompt} (default: '{default}'): ")
    return user_input if user_input else default

def ask_user_to_update(key: str, local_file_value: str, template_value: str) -> str:
    print(f"The value for '{key}' in the second file differs from the first file.")
    choice = input(f"Do you want to update it with the value from the first file? ({template_value}) (y/n): ").lower()
    if choice == "y":
        return template_value
    return local_file_value

def main():
    if len(sys.argv) != 4:
        print(f"Usage: {sys.argv[0]} <template-file> <file-to-update> <new-file>")
        sys.exit(1)

    template_file, file_to_update, new_file = sys.argv[1], sys.argv[2], sys.argv[3]

    if not os.path.isfile(template_file):
        print(f"Error: Template file '{template_file}' does not exist.")
        sys.exit(1)

    if not os.path.isfile(file_to_update):
        print(f"Error: File to update '{file_to_update}' does not exist.")
        sys.exit(1)

    vars_to_update = {}
    vars_in_template = {}

    with open(file_to_update) as f:
        for line in f:
            if '=' in line and not line.startswith('#'):
                key, value = extract_key_value(line)
                vars_to_update[key] = value

    new_content = []

    with open(template_file) as f:
        help_text = ""
        for line in f:
            if line.startswith('#') and help_text:
                help_text += line
            elif '=' in line:
                key, value = extract_key_value(line)
                vars_in_template[key] = value
                if key in vars_to_update:
                    if vars_to_update[key] != vars_in_template[key]:
                        updated_value = ask_user_to_update(key, vars_to_update[key], vars_in_template[key])
                        new_content.extend(["\n", f"# Updated by {os.environ['USER']} on {datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}\n", f"{key}={updated_value}\n"])
                    else:
                        new_content.append(f"{key}={vars_to_update[key]}\n")
                    del vars_to_update[key]
                else:
                    new_value = get_user_input(f"Enter a new value for {key}", value)
                    new_content.extend(["\n", f"# Added by {os.environ['USER']} on {datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}\n", f"{key}={new_value}\n"])
                    print(f"Added new variable {key} with value: {new_value}")
                help_text = ""
            else:
                new_content.append(line)

    print("Checking for obsolete variables ...")
    for key, value in vars_to_update.items():
        if key not in vars_in_template:
            print(f"Warning: Variable {key} with value {value} might be obsolete.")

    with open(new_file, "w") as f:
        f.writelines(new_content)

    print(f"Done updating. Changes written to '{new_file}'.")

if __name__ == "__main__":
    main()

env_master.txt

# This is a comment that should be copied as is
# This is a comment that should be copied as is
# This is a comment that should be copied as is


COMPOSE_PROJECT_NAME=geonode
DOCKERHOST=123.123.124
DOCKER_HOST_IP=
# See https://github.com/containers/podman/issues/13889
# DOCKER_BUILDKIT=0
DOCKER_ENV=production
ALLOWED_HOSTS=["*"]

env_4.0.txt

COMPOSE_PROJECT_NAME=geonode
DOCKERHOST=
# See https://github.com/containers/podman/issues/13889
ALLOWED_HOSTS=["localhost", "127.0.0.1"]

run with

python fix_env_file.py env_master.txt env_4.0.txt new.txt