Support for Self signed certificate

[thejockel]

Hey,
I am not able to receive data from my registry. The registry uses a Self signed certificate.
Please add support to disable SSL Cert Verification.

THX Jockel

$ gitlab-registry-usage -r ***************** -g ************** -u *********
Password: 

Traceback (most recent call last):
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/connectionpool.py", line 699, in urlopen
    httplib_response = self._make_request(
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/connectionpool.py", line 382, in _make_request
    self._validate_conn(conn)
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/connectionpool.py", line 1010, in _validate_conn
    conn.connect()
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/connection.py", line 416, in connect
    self.sock = ssl_wrap_socket(
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/util/ssl_.py", line 449, in ssl_wrap_socket
    ssl_sock = _ssl_wrap_socket_impl(
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/util/ssl_.py", line 493, in _ssl_wrap_socket_impl
    return ssl_context.wrap_socket(sock, server_hostname=server_hostname)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/ssl.py", line 500, in wrap_socket
    return self.sslsocket_class._create(
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/ssl.py", line 1040, in _create
    self.do_handshake()
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/ssl.py", line 1309, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate (_ssl.c:1125)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/connectionpool.py", line 755, in urlopen
    retries = retries.increment(
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/urllib3/util/retry.py", line 574, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='', port=9444): Max retries exceeded with url: /v2/_catalog?n=16384 (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate (_ssl.c:1125)')))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/<my_username>/Library/Python/3.8/bin/gitlab-registry-usage", line 8, in <module>
    sys.exit(main())
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/gitlab_registry_usage/cli.py", line 308, in main
    query_gitlab_registry(
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/gitlab_registry_usage/cli.py", line 180, in query_gitlab_registry
    [len(repository) for repository in gitlab_registry.registry_catalog]
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/gitlab_registry_usage/registry/high_level_api.py", line 122, in registry_catalog
    self._registry_catalog = get_registry_catalog(self._registry_url, catalog_auth_token)
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/gitlab_registry_usage/registry/low_level_api.py", line 65, in get_registry_catalog
    response = requests.get(catalog_url, headers={"Authorization": "Bearer " + auth_token})
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/requests/api.py", line 75, in get
    return request('get', url, params=params, **kwargs)
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)
  File "/Users/<my_username>/Library/Python/3.8/lib/python/site-packages/requests/adapters.py", line 514, in send
    raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='<internal URL>', port=9444): Max retries exceeded with url: /v2/_catalog?n=16384 (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate (_ssl.c:1125)')))