get-next-uid-gid.py

#!/usr/bin/env python
import sys
import json
import ldap
import logging
import argparse
import rc_util
from os import popen
from rc_rmq import RCRMQ

task = 'get_next_uid_gid'

# Instantiate rabbitmq object
rc_rmq = RCRMQ({'exchange': 'RegUsr', 'exchange_type': 'topic'})

args = rc_util.get_args()

# Logger
logger = rc_util.get_logger()

# Define your callback function
def get_next_uid_gid(ch, method, properties, body):

    # Retrieve message
    msg = json.loads(body)
    logger.info("Received {}".format(msg))
    username = msg['username']
    success = False

    # Determine next available UID
    try:
        user_exists_cmd = "/usr/bin/getent passwd {username}"
        user_exists = popen(user_exists_cmd).read().rstrip()

        if user_exists:
            logger.info("The user, {} already exists".format(username))
            msg['uid'] = user_exists.split(':')[2] 
            msg['gid'] = user_exists.split(':')[3]

        else:
            cmd_uid = "/usr/bin/getent passwd | \
                awk -F: '($3>10000) && ($3<20000) && ($3>maxuid) { maxuid=$3; } END { print maxuid+1; }'"
            msg['uid'] = popen(cmd_uid).read().rstrip()
            logger.info(f"UID query: {cmd_uid}")

            cmd_gid = "/usr/bin/getent group | \
                awk -F: '($3>10000) && ($3<20000) && ($3>maxgid) { maxgid=$3; } END { print maxgid+1; }'"
            msg['gid'] = popen(cmd_gid).read().rstrip()
            logger.info(f"GID query: {cmd_gid}")
        msg['task'] = task
        msg['success'] = True
    except Exception:
        logger.exception("Fatal error:")

    # Acknowledge message
    ch.basic_ack(delivery_tag=method.delivery_tag)

    # Send confirm message
    logger.debug('rc_rmq.publish_msg()')
    rc_rmq.publish_msg({
        'routing_key': 'confirm.' + username,
        'msg': msg
    })
    logger.info('confirmation sent')

logger.info("Start listening to queue: {}".format(task))
rc_rmq.start_consume({
    'queue': task,
    'routing_key': "request.*",
    'cb': get_next_uid_gid
})

logger.info("Disconnected")
rc_rmq.disconnect()