Handle various exceptions

[t0ny-peng]

• Bad Gateway

Traceback (most recent call last):
  File "/home/marge-bot/marge-bot/marge.app", line 3, in <module>
    marge.app.main()
  File "/home/marge-bot/marge-bot/marge/app.py", line 281, in main
    marge_bot.start()
  File "/home/marge-bot/marge-bot/marge/bot.py", line 42, in start
    self._run(repo_manager)
  File "/home/marge-bot/marge-bot/marge/bot.py", line 56, in _run
    projects = self._get_projects()
  File "/home/marge-bot/marge-bot/marge/bot.py", line 70, in _get_projects
    my_projects = Project.fetch_all_mine(self._api)
  File "/home/marge-bot/marge-bot/marge/project.py", line 32, in fetch_all_mine
    {'membership': True, 'with_merge_requests_enabled': True},
  File "/home/marge-bot/marge-bot/marge/gitlab.py", line 61, in collect_all_pages
    page = self.call(get_command.for_page(page_no))
  File "/home/marge-bot/marge-bot/marge/gitlab.py", line 55, in call
    raise error(response.status_code, err_message)
marge.gitlab.InternalServerError: (502, 'Bad Gateway')

• Connection refused

Traceback (most recent call last):
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connection.py", line 159, in _new_conn
    (self._dns_host, self.port), self.timeout, **extra_kw)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/util/connection.py", line 80, in create_connection
    raise err
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/util/connection.py", line 70, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [Errno 111] Connection refused

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 600, in urlopen
    chunked=chunked)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 343, in _make_request
    self._validate_conn(conn)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 839, in _validate_conn
    conn.connect()
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connection.py", line 301, in connect
    conn = self._new_conn()
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connection.py", line 168, in _new_conn
    self, "Failed to establish a new connection: %s" % e)
urllib3.exceptions.NewConnectionError: <urllib3.connection.VerifiedHTTPSConnection object at 0x7f90ab1bd2b0>: Failed to establish a new connection: [Errno 111] Connection refused

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/adapters.py", line 449, in send
    timeout=timeout
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 638, in urlopen
    _stacktrace=sys.exc_info()[2])
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/util/retry.py", line 398, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='gitlab.apex.ai', port=443): Max retries exceeded with url: /api/v4/projects?with_merge_requests_enabled=true&membership=true&page=1&per_page=100 (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x7f90ab1bd2b0>: Failed to establish a new connection: [Errno 111] Connection refused',))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/marge-bot/marge-bot/marge.app", line 3, in <module>
    marge.app.main()
  File "/home/marge-bot/marge-bot/marge/app.py", line 281, in main
    marge_bot.start()
  File "/home/marge-bot/marge-bot/marge/bot.py", line 42, in start
    self._run(repo_manager)
  File "/home/marge-bot/marge-bot/marge/bot.py", line 56, in _run
    projects = self._get_projects()
  File "/home/marge-bot/marge-bot/marge/bot.py", line 70, in _get_projects
    my_projects = Project.fetch_all_mine(self._api)
  File "/home/marge-bot/marge-bot/marge/project.py", line 32, in fetch_all_mine
    {'membership': True, 'with_merge_requests_enabled': True},
  File "/home/marge-bot/marge-bot/marge/gitlab.py", line 61, in collect_all_pages
    page = self.call(get_command.for_page(page_no))
  File "/home/marge-bot/marge-bot/marge/gitlab.py", line 20, in call
    response = method(url, headers=headers, **command.call_args)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/api.py", line 75, in get
    return request('get', url, params=params, **kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/api.py", line 60, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/sessions.py", line 533, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/sessions.py", line 646, in send
    r = adapter.send(request, **kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/adapters.py", line 516, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='gitlab.apex.ai', port=443): Max retries exceeded with url: /api/v4/projects?with_merge_requests_enabled=true&membership=true&page=1&per_page=100 (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x7f90ab1bd2b0>: Failed to establish a new connection: [Errno 111] Connection refused',))

• Name resolution error

Traceback (most recent call last):
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connection.py", line 159, in _new_conn
    (self._dns_host, self.port), self.timeout, **extra_kw)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/util/connection.py", line 57, in create_connection
    for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):
  File "/usr/lib/python3.5/socket.py", line 732, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -3] Temporary failure in name resolution

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 600, in urlopen
    chunked=chunked)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 343, in _make_request
    self._validate_conn(conn)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 839, in _validate_conn
    conn.connect()
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connection.py", line 301, in connect
    conn = self._new_conn()
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connection.py", line 168, in _new_conn
    self, "Failed to establish a new connection: %s" % e)
urllib3.exceptions.NewConnectionError: <urllib3.connection.VerifiedHTTPSConnection object at 0x7ff3ba868ba8>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/adapters.py", line 449, in send
    timeout=timeout
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/connectionpool.py", line 638, in urlopen
    _stacktrace=sys.exc_info()[2])
  File "/home/marge-bot/.local/lib/python3.5/site-packages/urllib3/util/retry.py", line 398, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='gitlab.apex.ai', port=443): Max retries exceeded with url: /api/v4/projects?per_page=100&with_merge_requests_enabled=true&membership=true&page=1 (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x7ff3ba868ba8>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution',))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/marge-bot/marge-bot/marge.app", line 3, in <module>
    marge.app.main()
  File "/home/marge-bot/marge-bot/marge/app.py", line 281, in main
    marge_bot.start()
  File "/home/marge-bot/marge-bot/marge/bot.py", line 42, in start
    self._run(repo_manager)
  File "/home/marge-bot/marge-bot/marge/bot.py", line 56, in _run
    projects = self._get_projects()
  File "/home/marge-bot/marge-bot/marge/bot.py", line 70, in _get_projects
    my_projects = Project.fetch_all_mine(self._api)
  File "/home/marge-bot/marge-bot/marge/project.py", line 32, in fetch_all_mine
    {'membership': True, 'with_merge_requests_enabled': True},
  File "/home/marge-bot/marge-bot/marge/gitlab.py", line 61, in collect_all_pages
    page = self.call(get_command.for_page(page_no))
  File "/home/marge-bot/marge-bot/marge/gitlab.py", line 20, in call
    response = method(url, headers=headers, **command.call_args)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/api.py", line 75, in get
    return request('get', url, params=params, **kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/api.py", line 60, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/sessions.py", line 533, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/sessions.py", line 646, in send
    r = adapter.send(request, **kwargs)
  File "/home/marge-bot/.local/lib/python3.5/site-packages/requests/adapters.py", line 516, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='gitlab.apex.ai', port=443): Max retries exceeded with url: /api/v4/projects?per_page=100&with_merge_requests_enabled=true&membership=true&page=1 (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x7ff3ba868ba8>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution',))