dockerfiletohelm.py

#!/usr/bin/env python3

import click
import yaml

# define a custom representer for strings
def quoted_presenter(dumper, data):
    return dumper.represent_scalar('tag:yaml.org,2002:str', data, style='"')

yaml.add_representer(str, quoted_presenter)

def RepresentsInt(s):
    try:
        int(s)
        return True
    except ValueError:
        return False


@click.command()
@click.option('--filename', prompt='File',
              help='Dockerfile to parse')
def deployment(filename='Dockerfile'):
    """Simple program that transforms docker file
    ENV sequence into helm env vars"""

    dockerfile = open(filename, 'r')
    lines = dockerfile.readlines()

    variables = []

    for line in lines:
        if line.startswith("ENV"):
            line = line.replace("<account name> <account key>", "account_name account_key")
            line = line.replace("<account name>", "account_name")
            parts = line.split()
            pair = dict()
            pair["name"] = parts[1]
            if (1==1):
                pair["value"] = parts[2]
            elif (parts[2].isnumeric()):
                if (RepresentsInt(parts[2])):
                    pair["value"] = int(parts[2])
                else:
                    pair["value"] = float(parts[2])
            elif (parts[2] == "true" or parts[2] == "false"):
                pair["value"] = parts[2].lower() in ['true', '1']
            else:
                pair["value"] = parts[2]
            variables.append(pair)

    output = dict()
    output["env"] = variables

    output_str = yaml.dump(output)
    output_str = output_str.replace('"name":', 'name:')
    output_str = output_str.replace('"value":', 'value:')
    output_str = output_str.replace('"env":', 'env:')

    print(output_str)


if __name__ == '__main__':
    deployment()