Merge pull request #158 from dbt-msft/token_timeout_fix

refresh token if within 5 minutes of expiring; else reuse

Author: dataders

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+### v0.20.1
+
+#### fixes:
+
+- workaround for Azure CLI token expires after one hour. Now we get new tokens for every transaction. [#156](https://github.com/dbt-msft/dbt-sqlserver/issue/156) [#158](https://github.com/dbt-msft/dbt-sqlserver/pull/158)
+
 ### v0.20.0
 
 #### features:

dbt/adapters/sqlserver/__version__.py

@@ -1 +1 @@
-version = '0.20.0'
+version = '0.20.1'

dbt/adapters/sqlserver/connections.py

@@ -185,6 +185,7 @@ def get_pyodbc_attrs_before(credentials: SQLServerCredentials) -> Dict:
     """
     global _TOKEN
     attrs_before: Dict
+    MAX_REMAINING_TIME = 300
 
     azure_auth_function_type = Callable[[SQLServerCredentials], AccessToken]
     azure_auth_functions: Mapping[str, azure_auth_function_type] = {
@@ -193,21 +194,24 @@ def get_pyodbc_attrs_before(credentials: SQLServerCredentials) -> Dict:
     }
 
     authentication = credentials.authentication.lower()
-    if authentication not in azure_auth_functions:
-        attrs_before = {}
-    else:
-        azure_auth_function = azure_auth_functions[authentication]
-        _TOKEN = _TOKEN or azure_auth_function(credentials)
-        token_bytes = convert_access_token_to_mswindows_byte_string(_TOKEN)
+    if authentication in azure_auth_functions:
+        time_remaining = (_TOKEN.expires_on - time.time()) if _TOKEN else MAX_REMAINING_TIME
+
+        if _TOKEN is None or (time_remaining < MAX_REMAINING_TIME):
+            azure_auth_function = azure_auth_functions[authentication]
+            _TOKEN = azure_auth_function(credentials)
 
+        token_bytes = convert_access_token_to_mswindows_byte_string(_TOKEN)
         sql_copt_ss_access_token = 1256  # see source in docstring
         attrs_before = {sql_copt_ss_access_token: token_bytes}
+    else:
+        attrs_before = {}
+
     return attrs_before
 
 
 class SQLServerConnectionManager(SQLConnectionManager):
     TYPE = "sqlserver"
-    TOKEN = None
 
     @contextmanager
     def exception_handler(self, sql):