Script that takes supervisor configs describing lumberjack commands and converts them to a new-style Go-based lumberjack config file.

upgrade_lumberjack_configs.py

#!/usr/bin/python
"""Converts Lumberjack supervisor configs to the new-style JSON configs.

   USAGE: upgrade_lumberjack_configs.py SUPERVISOR_CONF [SUPERVISOR CONF ...]

   Assumptions:

       * All your lumberjack commands use the same --host, --port, and
         --ssl-ca-path arguments"""

import sys
import argparse
import json

SUPERVISOR_CONFIGS = sys.argv[1:]


def parse(command):
    """Parses a lumberjack invocation and returns an argparse result."""
    parser = argparse.ArgumentParser(prog='lumberjack')
    parser.add_argument('log_file', nargs='+', metavar='LOG_FILE')
    parser.add_argument('--field', action='append')
    parser.add_argument('--ssl-ca-path')
    parser.add_argument('--host')
    parser.add_argument('--port')
    parser.add_argument('--window-size')
    return parser.parse_args(command.split()[1:])


def lumb_network_params(invoc):
    """Returns the 'network' section of the new-style lumberjack config.

       See assumptions in the global docstring."""
    servers = [ '{host}:{port}'.format(host=invoc.host, port=invoc.port) ]
    ssl_ca = invoc.ssl_ca_path
    return {'servers': servers, 'ssl ca': ssl_ca}


def lumb_files_stanza(invoc):
    """Converts an argparse result to a new-style lumberjack config "files" stanza.

       Returns a dict of lumberjack config parameters."""
    rslt = {}
    rslt['paths'] = invoc.log_file
    rslt['fields'] = {}
    for field_arg in invoc.field:
        field_name, field_val = field_arg.split('=', 1)
        rslt['fields'][field_name] = field_val
    return rslt


# Get all the supervisor configs and make a list of the commands that they supervise
commands = []
for sup_conf_path in SUPERVISOR_CONFIGS:
    command_lines = [line.rstrip() for line in open(sup_conf_path).readlines()
                     if line.startswith('command=')]
    commands.extend([line.split('=', 1)[1] for line in command_lines])

# Filter down to just lumberjack commands
commands = [c for c in commands
            if c.split()[0].endswith('/lumberjack') or c.split()[0].endswith('/lumberjack.sh')]

# Parse each invocation
parsed_invocs = [parse(c) for c in commands]

# Get the global config parameters from the first invocation
rslt = {}
rslt['network'] = lumb_network_params(parsed_invocs[0])

# Convert each parsed invocation to a new-style lumberjack config "files" stanza
rslt['files'] = [lumb_files_stanza(invoc) for invoc in parsed_invocs]

# Print result
print json.dumps(rslt, indent=2)