[extractor/dplay] GlobalCyclingNetworkPlus: Add extractor (#7360)

* Allows `country` API param to be configured with `--xff`/`geo_bypass_country`

Closes #7324
Authored by: bashonly

yt_dlp/extractor/dplay.py

@@ -65,6 +65,7 @@ class DPlayBaseIE(InfoExtractor):
         return streaming_list
 
     def _get_disco_api_info(self, url, display_id, disco_host, realm, country, domain=''):
+        country = self.get_param('geo_bypass_country') or country
         geo_countries = [country.upper()]
         self._initialize_geo_bypass({
             'countries': geo_countries,
@@ -1001,3 +1002,39 @@ class DiscoveryPlusIndiaShowIE(DiscoveryPlusShowBaseIE):
     _SHOW_STR = 'show'
     _INDEX = 4
     _VIDEO_IE = DiscoveryPlusIndiaIE
+
+
+class GlobalCyclingNetworkPlusIE(DiscoveryPlusBaseIE):
+    _VALID_URL = r'https?://plus\.globalcyclingnetwork\.com/watch/(?P<id>\d+)'
+    _TESTS = [{
+        'url': 'https://plus.globalcyclingnetwork.com/watch/1397691',
+        'info_dict': {
+            'id': '1397691',
+            'ext': 'mp4',
+            'title': 'The Athertons: Mountain Biking\'s Fastest Family',
+            'description': 'md5:75a81937fcd8b989eec6083a709cd837',
+            'thumbnail': 'https://us1-prod-images.disco-api.com/2021/03/04/eb9e3026-4849-3001-8281-9356466f0557.png',
+            'series': 'gcn',
+            'creator': 'Gcn',
+            'upload_date': '20210309',
+            'timestamp': 1615248000,
+            'duration': 2531.0,
+            'tags': [],
+        },
+        'skip': 'Subscription required',
+        'params': {'skip_download': 'm3u8'},
+    }]
+
+    _PRODUCT = 'web'
+    _DISCO_API_PARAMS = {
+        'disco_host': 'disco-api-prod.globalcyclingnetwork.com',
+        'realm': 'gcn',
+        'country': 'us',
+    }
+
+    def _update_disco_api_headers(self, headers, disco_base, display_id, realm):
+        headers.update({
+            'x-disco-params': f'realm={realm}',
+            'x-disco-client': f'WEB:UNKNOWN:{self._PRODUCT}:27.3.2',
+            'Authorization': self._get_auth(disco_base, display_id, realm),
+        })