Copying configuration property files into mule-app.properties for deployment to Mulesoft MMC

copy_env.py

#!/usr/bin/env python
"""
Copy env from config file to mule-app.properties, this is useful for deploying to an MMC.  On cloudhub, you can set a 
variable (mule.env) to determine which property file will be loaded but on MMC this does not work.  This deployment script
may help. 

Dirk P. Janssen
Spring 2017
"""

import argparse
import doctest
import logging
import re

logging.basicConfig()
logger = logging.getLogger("copy_env")
config_src_template = "src/main/resources/config/%s.properties"
config_dest = "src/main/app/mule-app.properties"

cut_here = "##-cut here-##"
cut_here_re = re.compile(cut_here)

def smart_concat(linesFrom, linesTo):
    """"Copy linesFrom to the end of linesTo, removing parts of lineTo after
    optional break indicator ('##-cut here-##') and inserting such an indicator"""

    for lineno, line in enumerate(linesTo):
        if cut_here_re.match(line):
            result = linesTo[:lineno]
            break
    else:
        result = linesTo[:]
    result.append(cut_here + "\n")
    result.extend(linesFrom)
    return result


def apply_vars(environment, verbose=False):
    environmentFilename = config_src_template % environment
    logger.info("Reading environment file %s", environmentFilename)

    newstuff = open(environmentFilename).readlines()
    logger.info("Environment file:  %d lines", len(newstuff))
    with open(config_dest) as destfile:
        contents = destfile.readlines()
    logger.info("Destination file:  %d lines before operation", len(contents))
    
    contents = smart_concat(newstuff, contents)
    logger.info("Destination file:  %d lines after operation", len(contents))
    contents = "".join(contents)
    with open(config_dest, "w") as destfile:
        destfile.write(contents)
            

def main():
    parser = argparse.ArgumentParser(description='Apply environment variables')
    parser.add_argument('environment', help="Environment name")
    parser.add_argument('--verbose', '-v', action="store_true",
                        help="Show details of operation")
    args = parser.parse_args()
    logger.setLevel(logging.INFO if args.verbose else logging.WARNING)

    apply_vars(args.environment)


    

if __name__ == '__main__':
    main()

test_copy_env.py

import copy_env
import unittest

class Test_smart_concat(unittest.TestCase):

        
    def test_basic_op(self):
        linesTo = """lineA/lineB/##-cut here-## old stuff/line C""".split("/")
        linesFrom = """fromA/fromB/fromC""".split("/")
        result = copy_env.smart_concat(linesFrom, linesTo)
        expected = """lineA/lineB/##-cut here-##\n/fromA/fromB/fromC""".split("/")
        self.assertEqual(result, expected)

        
    def test_no_cut(self):
        linesTo = """lineA/lineB""".split("/")
        linesFrom = """fromA/fromB/fromC""".split("/")
        result = copy_env.smart_concat(linesFrom, linesTo)
        expected = """lineA/lineB/##-cut here-##\n/fromA/fromB/fromC""".split("/")
        self.assertEqual(result, expected)