Get json object from string with an embedded json string

main.py

import regex
import json

input_string = '''2020-12-23T07:23:18.000000+05:30 45.79.121.190 {"hostname":"abc.members.linode.com","os":{"name":"CentOS Linux","family":"redhat","version":"7 (Core)","platform":"centos","kernel":"3.10.0-1127.13.1.el7.x86_64","codename":"Core"},"containerized":false,"ip":["44.75.121.190","2400:8904::f03c:92ff:fed4:e4f0","fe80::f03c:92ff:fed4:e4f0"],"name":"abc.members.linode.com","cpu":{"pct":0.062},"id":"c29d751565e74afdbaade6c8a36dd2ef","mac":["f2:3c:92:d4:e4:f0"],"architecture":"x86_64"} LOGSTASH[-]: 2020-12-23T07:23:18.995Z {hostname=abc.members.linode.com, os={name=CentOS Linux, family=redhat, version=7 (Core), platform=centos, kernel=3.10.0-1127.13.1.el7.x86_64, codename=Core}, containerized=false, ip=[44.75.121.190, 2400:8904::f03c:92ff:fed4:e4f0, fe80::f03c:92ff:fed4:e4f0], name=abc.members.linode.com, cpu={pct=0.062}, id=c29d751565e74afdbaade6c8a36dd2ef, mac=[f2:3c:92:d4:e4:f0], architecture=x86_64} %{message}'''

# def get_json2(input_str):
#     start = input_str.find('{')
#     end = input_str.find('LOGSTASH[')
#     try:
#         x = input_str[start:end]
#         x = json.loads(x)
#         return x
#     except Exception as err:
#         print(f"ERROR not found. start={start}, end={end}, err={err}")
#         return {}

# print(get_json2(input_string))

# def get_json(input_str):
#     l = []
#     for i, c in enumerate(input_str):
#         if (c == '{'):
#             l.append([c, i])
#         if (c == '}'):
#             t = l.pop()
#             print(f"\n{c} end at {i}, start at: {t}: {input_str[t[1]:i + 1]}")
#             try:
#                 x = json.loads(input_str[t[1]:i + 1])
#                 if 'hostname' in x:
#                     print("--- FOUND")
#                     return x
#             except Exception as err:
#                 print(f"Exception: {err}")
#                 pass
#
#     return {}

# print(get_json(input_string))

pattern = regex.compile(r'\{(?:[^{}]|(?R))*\}')
x = pattern.findall(input_string)
x = json.loads(x[0])
assert 'hostname' in x