Updated Blender ID add-on from upstream

Includes:

- 069540e (2019-05-16) Bumped version to 1.9.99
- cf48253 (2019-05-16) Include Blender and add-on version in User-Agent header
- 4b3d527 (2019-05-16) Automatically retry failed connections to Blender ID for more stability

3 files changed, 61 insertions, 20 deletions

diff --git a/blender_id/CHANGELOG.md b/blender_id/CHANGELOG.md
index ee36a7fe..cb0c1868 100644
--- a/blender_id/CHANGELOG.md
+++ b/blender_id/CHANGELOG.md
@@ -8,6 +8,8 @@
 - Log which Blender ID instance is communicated with.
 - Show which Blender ID instance is communicated with in the addon preferences,
   if it was overridden by setting the BLENDER_ID_ENDPOINT environment variable.
+- Automatically retry failed connections to Blender ID for more stability.
+- Include Blender and add-on version in User-Agent header when communicating with Blender ID.
 
 
 # Version 1.5 (released 2018-07-03)
diff --git a/blender_id/__init__.py b/blender_id/__init__.py
index 496c867d..42d7df02 100644
--- a/blender_id/__init__.py
+++ b/blender_id/__init__.py
@@ -23,7 +23,7 @@
 bl_info = {
     'name': 'Blender ID authentication',
     'author': 'Sybren A. Stüvel, Francesco Siddi, and Inês Almeida',
-    'version': (1, 9, 9),
+    'version': (1, 9, 99),
     'blender': (2, 80, 0),
     'location': 'Add-on preferences',
     'description':
diff --git a/blender_id/communication.py b/blender_id/communication.py
index 65fdf4cf..72bf90fe 100644
--- a/blender_id/communication.py
+++ b/blender_id/communication.py
@@ -27,6 +27,9 @@ log = logging.getLogger(__name__)
 # Can be overridden by setting the environment variable BLENDER_ID_ENDPOINT.
 BLENDER_ID_ENDPOINT = 'https://www.blender.org/id/'
 
+# Will become a requests.Session at the first request to Blender ID.
+requests_session = None
+
 
 class BlenderIdCommError(RuntimeError):
     """Raised when there was an error communicating with Blender ID"""
@@ -50,6 +53,41 @@ def host_label():
     return 'Blender running on %r' % socket.gethostname()
 
 
+def blender_id_session():
+    """Returns the Requests session, creating it if necessary."""
+    global requests_session
+    import requests
+
+    if requests_session is not None:
+        return requests_session
+
+    requests_session = requests.session()
+
+    # Retry with backoff factor, so that a restart of Blender ID or hickup
+    # in the connection doesn't immediately fail the request.
+    retries = requests.packages.urllib3.util.retry.Retry(
+        total=10,
+        backoff_factor=0.05,
+    )
+    http_adapter = requests.adapters.HTTPAdapter(max_retries=retries)
+    requests_session.mount('https://', http_adapter)
+    requests_session.mount('http://', http_adapter)
+
+    # Construct the User-Agent header with Blender and add-on versions.
+    try:
+        import bpy
+    except ImportError:
+        blender_version = 'unknown'
+    else:
+        blender_version = '.'.join(str(component) for component in bpy.app.version)
+
+    from blender_id import bl_info
+    addon_version = '.'.join(str(component) for component in bl_info['version'])
+    requests_session.headers['User-Agent'] = f'Blender/{blender_version} Blender-ID-Addon/{addon_version}'
+
+    return requests_session
+
+
 @functools.lru_cache(maxsize=None)
 def blender_id_endpoint(endpoint_path=None):
     """Gets the endpoint for the authentication API. If the BLENDER_ID_ENDPOINT env variable
@@ -80,7 +118,6 @@ def blender_id_server_authenticate(username, password) -> AuthResult:
     message. Problems may be with the connection or wrong user/password.
     """
 
-    import requests
     import requests.exceptions
 
     payload = dict(
@@ -90,8 +127,9 @@ def blender_id_server_authenticate(username, password) -> AuthResult:
     )
 
     url = blender_id_endpoint('u/identify')
+    session = blender_id_session()
     try:
-        r = requests.post(url, data=payload, verify=True)
+        r = session.post(url, data=payload, verify=True)
     except (requests.exceptions.SSLError,
             requests.exceptions.HTTPError,
             requests.exceptions.ConnectionError) as e:
@@ -126,12 +164,12 @@ def blender_id_server_validate(token) -> typing.Tuple[typing.Optional[str], typi
         The error is None if the token is valid, or an error message when it's invalid.
     """
 
-    import requests
     import requests.exceptions
 
     url = blender_id_endpoint('u/validate_token')
+    session = blender_id_session()
     try:
-        r = requests.post(url, data={'token': token}, verify=True)
+        r = session.post(url, data={'token': token}, verify=True)
     except requests.exceptions.ConnectionError:
         log.exception('error connecting to Blender ID at %s', url)
         return None, 'Unable to connect to Blender ID'
@@ -157,16 +195,16 @@ def blender_id_server_logout(user_id, token):
     @rtype: dict
     """
 
-    import requests
     import requests.exceptions
 
     payload = dict(
         user_id=user_id,
         token=token
     )
+    session = blender_id_session()
     try:
-        r = requests.post(blender_id_endpoint('u/delete_token'),
-                          data=payload, verify=True)
+        r = session.post(blender_id_endpoint('u/delete_token'),
+                         data=payload, verify=True)
     except (requests.exceptions.SSLError,
             requests.exceptions.HTTPError,
             requests.exceptions.ConnectionError) as e:
@@ -217,15 +255,15 @@ def subclient_create_token(auth_token: str, subclient_id: str) -> dict:
 def make_authenticated_call(method, url, auth_token, data):
     """Makes a HTTP call authenticated with the OAuth token."""
 
-    import requests
     import requests.exceptions
 
+    session = blender_id_session()
     try:
-        r = requests.request(method,
-                             blender_id_endpoint(url),
-                             data=data,
-                             headers={'Authorization': 'Bearer %s' % auth_token},
-                             verify=True)
+        r = session.request(method,
+                            blender_id_endpoint(url),
+                            data=data,
+                            headers={'Authorization': 'Bearer %s' % auth_token},
+                            verify=True)
     except (requests.exceptions.HTTPError,
             requests.exceptions.ConnectionError) as e:
         raise BlenderIdCommError(str(e))
@@ -244,16 +282,17 @@ def send_token_to_subclient(webservice_endpoint: str, user_id: str,
     :returns: the user ID at the subclient.
     """
 
-    import requests
+    import requests.exceptions
     import urllib.parse
 
     url = urllib.parse.urljoin(webservice_endpoint, 'blender_id/store_scst')
+    session = blender_id_session()
     try:
-        r = requests.post(url,
-                          data={'user_id': user_id,
-                                'subclient_id': subclient_id,
-                                'token': subclient_token},
-                          verify=True)
+        r = session.post(url,
+                         data={'user_id': user_id,
+                               'subclient_id': subclient_id,
+                               'token': subclient_token},
+                         verify=True)
         r.raise_for_status()
     except (requests.exceptions.HTTPError,
             requests.exceptions.ConnectionError) as e: