Bugfix/issue 3350 snowflake non json response (#3365)

* attempt at solving with while loop

* added comment on loop

* update changelog

* modified per drew's suggestions

* updates after linting

CHANGELOG.md

@@ -16,6 +16,7 @@
 - Separate `compiled_path` from `build_path`, and print the former alongside node error messages ([#1985](https://github.com/fishtown-analytics/dbt/issues/1985), [#3327](https://github.com/fishtown-analytics/dbt/pull/3327))
 - Fix exception caused when running `dbt debug` with BigQuery connections ([#3314](https://github.com/fishtown-analytics/dbt/issues/3314), [#3351](https://github.com/fishtown-analytics/dbt/pull/3351))
 - Raise better error if snapshot is missing required configurations ([#3381](https://github.com/fishtown-analytics/dbt/issues/3381), [#3385](https://github.com/fishtown-analytics/dbt/pull/3385))
+- Fix `dbt run` errors caused from receiving non-JSON responses from Snowflake with Oauth ([#3350](https://github.com/fishtown-analytics/dbt/issues/3350)
 
 ### Under the hood
 - Added logic for registry requests to raise a timeout error after a response hangs out for 30 seconds and 5 attempts have been made to reach the endpoint ([#3177](https://github.com/fishtown-analytics/dbt/issues/3177), [#3275](https://github.com/fishtown-analytics/dbt/pull/3275))
@@ -32,6 +33,7 @@ Contributors:
 - [@jaypeedevlin](https://github.com/jaypeedevlin) ([#2999](https://github.com/fishtown-analytics/dbt/issues/2999))
 - [@PJGaetan](https://github.com/PJGaetan) ([#3315](https://github.com/fishtown-analytics/dbt/pull/3376))
 - [@jnatkins](https://github.com/jnatkins) ([#3385](https://github.com/fishtown-analytics/dbt/pull/3385))
+- [@matt-winkler](https://github.com/matt-winkler) ([#3365](https://github.com/fishtown-analytics/dbt/pull/3365))
 
 ## dbt 0.20.0b1 (May 03, 2021)
 

plugins/snowflake/dbt/adapters/snowflake/connections.py

@@ -5,6 +5,7 @@
 from contextlib import contextmanager
 from dataclasses import dataclass
 from io import StringIO
+from time import sleep
 from typing import Optional
 
 from cryptography.hazmat.backends import default_backend
@@ -106,6 +107,7 @@ def _get_access_token(self) -> str:
                 'need a client ID a client secret, and a refresh token to get '
                 'an access token'
             )
+
         # should the full url be a config item?
         token_url = _TOKEN_REQUEST_URL.format(self.account)
         # I think this is only used to redirect on success, which we ignore
@@ -125,10 +127,25 @@ def _get_access_token(self) -> str:
             'Authorization': f'Basic {auth}',
             'Content-type': 'application/x-www-form-urlencoded;charset=utf-8'
         }
-        result = requests.post(token_url, headers=headers, data=data)
-        result_json = result.json()
-        if 'access_token' not in result_json:
-            raise DatabaseException(f'Did not get a token: {result_json}')
+
+        result_json = None
+        max_iter = 20
+        # Attempt to obtain JSON for 1 second before throwing an error
+        for i in range(max_iter):
+            result = requests.post(token_url, headers=headers, data=data)
+            try:
+                result_json = result.json()
+                break
+            except ValueError as e:
+                message = result.text
+                logger.debug(f"Got a non-json response ({result.status_code}): \
+                              {e}, message: {message}")
+                sleep(0.05)
+
+        if result_json is None:
+            raise DatabaseException(f"""Did not receive valid json with access_token.
+                                        Showing json response: {result_json}""")
+
         return result_json['access_token']
 
     def _get_private_key(self):