BigQuery keyfile_dict profile mapping use env vars for sensitive fields

cosmos/profiles/bigquery/service_account_keyfile_dict.py

@@ -3,6 +3,7 @@
 
 from typing import Any
 import json
+from cosmos.exceptions import CosmosValueError
 
 from cosmos.profiles.base import BaseProfileMapping
 
@@ -23,6 +24,8 @@
         "keyfile_json",
     ]
 
+    secret_fields = ["private_key_id", "private_key"]
+
     airflow_param_mapping = {
         "project": "extra.project",
         # multiple options for dataset because of older Airflow versions
@@ -31,6 +34,8 @@
         "keyfile_json": ["extra.keyfile_dict", "keyfile_dict", "extra__google_cloud_platform__keyfile_dict"],
     }
 
+    _env_vars: dict[str, str] = {}
+
     @property
     def profile(self) -> dict[str, Any | None]:
         """
@@ -48,12 +53,27 @@
 
     def transform_keyfile_json(self, keyfile_json: str | dict[str, str]) -> dict[str, str]:
         """
-        Transforms the keyfile_json param to a dict if it is a string.
+        Transforms the keyfile_json param to a dict if it is a string, and sets environment
+        variables for the service account json secret fields.
         """
         if isinstance(keyfile_json, dict):
-            return keyfile_json
-        keyfile_json = json.loads(keyfile_json)
-        if isinstance(keyfile_json, dict):
-            return keyfile_json
+            keyfile_json_dict = keyfile_json
         else:
-            raise ValueError("keyfile_json cannot be loaded as a dict.")
+            keyfile_json_dict = json.loads(keyfile_json)
+            if not isinstance(keyfile_json_dict, dict):
+                raise ValueError("keyfile_json cannot be loaded as a dict.")
+
+        for field in self.secret_fields:
+            value = keyfile_json_dict.get(field)
+            if value is None:
+                raise CosmosValueError(f"Could not find a value in service account json field: {field}.")
+            env_var_name = self.get_env_var_name(field)
+            self._env_vars[env_var_name] = value
+            keyfile_json_dict[field] = self.get_env_var_format(field)
+
+        return keyfile_json_dict
+
+    @property
+    def env_vars(self) -> dict[str, str]:
+        "Returns a dictionary of environment variables that should be set based on self.secret_fields."
+        return self._env_vars

tests/profiles/bigquery/test_bq_service_account_keyfile_dict.py

@@ -7,8 +7,14 @@
 from cosmos.profiles import get_automatic_profile_mapping
 from cosmos.profiles.bigquery.service_account_keyfile_dict import GoogleCloudServiceAccountDictProfileMapping
 
+sample_keyfile_dict = {
+    "type": "service_account",
+    "private_key_id": "my_private_key_id",
+    "private_key": "my_private_key",
+}
 
-@pytest.fixture(params=[{"key": "value"}, '{"key": "value"}'])
+
+@pytest.fixture(params=[sample_keyfile_dict, json.dumps(sample_keyfile_dict)])
 def mock_bigquery_conn_with_dict(request):  # type: ignore
     """
     Mocks and returns an Airflow BigQuery connection.
@@ -43,7 +49,7 @@ def test_connection_claiming_succeeds(mock_bigquery_conn_with_dict: Connection):
 
 def test_connection_claiming_fails(mock_bigquery_conn_with_dict: Connection):
     # Remove the `dataset` key, which is mandatory
-    mock_bigquery_conn_with_dict.extra = json.dumps({"project": "my_project", "keyfile_dict": {"key": "value"}})
+    mock_bigquery_conn_with_dict.extra = json.dumps({"project": "my_project", "keyfile_dict": sample_keyfile_dict})
     profile_mapping = GoogleCloudServiceAccountDictProfileMapping(mock_bigquery_conn_with_dict, {})
     assert not profile_mapping.can_claim_connection()
 
@@ -56,6 +62,24 @@ def test_profile(mock_bigquery_conn_with_dict: Connection):
         "project": "my_project",
         "dataset": "my_dataset",
         "threads": 1,
-        "keyfile_json": {"key": "value"},
+        "keyfile_json": {
+            "type": "service_account",
+            "private_key_id": "{{ env_var('COSMOS_CONN_GOOGLE_CLOUD_PLATFORM_PRIVATE_KEY_ID') }}",
+            "private_key": "{{ env_var('COSMOS_CONN_GOOGLE_CLOUD_PLATFORM_PRIVATE_KEY') }}",
+        },
     }
     assert profile_mapping.profile == expected
+
+
+def test_profile_env_vars(mock_bigquery_conn_with_dict: Connection):
+    """
+    Tests that the environment variables get set correctly.
+    """
+    profile_mapping = get_automatic_profile_mapping(
+        mock_bigquery_conn_with_dict.conn_id,
+        {"dataset": "my_dataset"},
+    )
+    assert profile_mapping.env_vars == {
+        "COSMOS_CONN_GOOGLE_CLOUD_PLATFORM_PRIVATE_KEY_ID": "my_private_key_id",
+        "COSMOS_CONN_GOOGLE_CLOUD_PLATFORM_PRIVATE_KEY": "my_private_key",
+    }