1"""LICENSE 

2Copyright 2020 Hermann Krumrey <hermann@krumreyh.com> 

3 

4This file is part of jerrycan. 

5 

6jerrycan is free software: you can redistribute it and/or modify 

7it under the terms of the GNU General Public License as published by 

8the Free Software Foundation, either version 3 of the License, or 

9(at your option) any later version. 

10 

11jerrycan is distributed in the hope that it will be useful, 

12but WITHOUT ANY WARRANTY; without even the implied warranty of 

13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

14GNU General Public License for more details. 

15 

16You should have received a copy of the GNU General Public License 

17along with jerrycan. If not, see <http://www.gnu.org/licenses/>. 

18LICENSE""" 

19 

20import sys 

21import time 

22import logging 

23import sentry_sdk 

24import traceback 

25from threading import Thread 

26# noinspection PyPackageRequirements 

27from telegram.error import TimedOut 

28from typing import Callable, Tuple, Dict, Type 

29from cheroot.wsgi import Server, PathInfoDispatcher 

30from jerrycan.background.telegram import telegram_whoami 

31from jerrycan.base import app 

32from jerrycan.Config import Config 

33 

34 

35def __start_background_tasks( 

36 task_definitions: Dict[str, Tuple[int, Callable]] 

37): 

38 """ 

39 Starts background tasks for a flask application 

40 :param task_definitions: The background tasks, consisting of: 

41 - the name of the task 

42 - the time to wait before running 

43 the task again 

44 - a function that takes no arguments that 

45 executes the task 

46 :return: None 

47 """ 

48 def task_factory(_name: str, _delay: int, _function: Callable) -> Thread: 

49 def run_task(): 

50 while True: 

51 try: 

52 with app.app_context(): 

53 _function() 

54 except Exception as error: 

55 app.logger.error(f"Encountered exception in " 

56 f"background task {_name}: {error}\n" 

57 f"{traceback.format_exc()}") 

58 sentry_sdk.capture_exception(error) 

59 time.sleep(_delay) 

60 return Thread(target=run_task) 

61 

62 tasks = [] 

63 for name, (delay, function) in task_definitions.items(): 

64 tasks.append(task_factory(name, delay, function)) 

65 

66 for thread in tasks: 

67 thread.start() 

68 

69 

70def start_server( 

71 config: Type[Config], 

72 task_definitions: Dict[str, Tuple[int, Callable]] 

73): 

74 """ 

75 Starts the flask application using a cheroot WSGI server 

76 :param config: The configuration to use 

77 :param task_definitions: The background tasks, consisting of: 

78 - the name of the task 

79 - the time to wait before running 

80 the task again 

81 - a function that takes no arguments that 

82 executes the task 

83 :return: None 

84 """ 

85 if not config.TELEGRAM_API_KEY == "" \ 

86 and not config.TESTING \ 

87 and config.TELEGRAM_WHOAMI: # pragma: no cover 

88 try: 

89 config.initialize_telegram() 

90 Config.TELEGRAM_BOT_CONNECTION.bot.logger.setLevel(logging.WARNING) 

91 except TimedOut: 

92 print("Could not initialize telegram") 

93 sys.exit(1) 

94 task_definitions.update({ 

95 "telegram_bg": (30, telegram_whoami) 

96 }) 

97 __start_background_tasks(task_definitions) 

98 

99 app.logger.info("STARTING FLASK") 

100 server = Server( 

101 ("0.0.0.0", config.HTTP_PORT), 

102 PathInfoDispatcher({"/": app}) 

103 ) 

104 

105 try: 

106 server.start() 

107 except KeyboardInterrupt: 

108 server.stop()