[GitHub] [airflow] mik-laj commented on a change in pull request #7795: [AIRFLOW-7104] Add Secret backend for GCP Secrets Manager

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mik-laj commented on a change in pull request #7795:
URL: https://github.com/apache/airflow/pull/7795#discussion_r421816660



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File path: airflow/providers/google/cloud/secrets/secrets_manager.py
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@@ -0,0 +1,132 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+"""
+Objects relating to sourcing connections from GCP Secrets Manager
+"""
+from typing import List, Optional
+
+from cached_property import cached_property
+from google.api_core.exceptions import NotFound
+from google.api_core.gapic_v1.client_info import ClientInfo
+from google.cloud.secretmanager_v1 import SecretManagerServiceClient
+
+from airflow import version
+from airflow.models import Connection
+from airflow.providers.google.cloud.utils.credentials_provider import (
+    _get_scopes, get_credentials_and_project_id,
+)
+from airflow.secrets import BaseSecretsBackend
+from airflow.utils.log.logging_mixin import LoggingMixin
+
+
+class CloudSecretsManagerSecretsBackend(BaseSecretsBackend, LoggingMixin):
+    """
+    Retrieves Connection object from GCP Secrets Manager
+
+    Configurable via ``airflow.cfg`` as follows:
+
+    .. code-block:: ini
+
+        [secrets]
+        backend = airflow.providers.google.cloud.secrets.secrets_manager.CloudSecretsManagerSecretsBackend
+        backend_kwargs = {"connections_prefix": "airflow/connections"}
+
+    For example, if secret id is ``airflow/connections/smtp_default``, this would be accessible
+    if you provide ``{"connections_prefix": "airflow/connections"}`` and request conn_id ``smtp_default``.
+
+    :param connections_prefix: Specifies the prefix of the secret to read to get Connections.
+    :type connections_prefix: str
+    :param gcp_key_path: Path to GCP Credential JSON file;
+        use default credentials in the current environment if not provided.
+    :type gcp_key_path: str
+    :param gcp_scopes: Comma-separated string containing GCP scopes
+    :type gcp_scopes: str
+    """
+    def __init__(
+        self,
+        connections_prefix: str = "airflow/connections",
+        gcp_key_path: Optional[str] = None,
+        gcp_scopes: Optional[str] = None,
+        **kwargs
+    ):
+        self.connections_prefix = connections_prefix.rstrip("/")
+        self.gcp_key_path = gcp_key_path
+        self.gcp_scopes = gcp_scopes
+        self.credentials: Optional[str] = None
+        self.project_id: Optional[str] = None
+        super().__init__(**kwargs)
+
+    @cached_property
+    def client(self) -> SecretManagerServiceClient:
+        """
+        Create an authenticated KMS client
+        """
+        scopes = _get_scopes(self.gcp_scopes)
+        self.credentials, self.project_id = get_credentials_and_project_id(
+            key_path=self.gcp_key_path,
+            scopes=scopes
+        )
+        _client = SecretManagerServiceClient(
+            credentials=self.credentials,
+            client_info=ClientInfo(client_library_version='airflow_v' + version.version)
+        )
+        return _client
+
+    def build_secret_id(self, conn_id: str) -> str:
+        """
+        Given conn_id, build path for Secrets Manager
+
+        :param conn_id: connection id
+        :type conn_id: str
+        """
+        secret_id = f"{self.connections_prefix}/{conn_id}"
+        return secret_id
+
+    def get_conn_uri(self, conn_id: str) -> Optional[str]:
+        """
+        Get secret value from Secrets Manager.
+
+        :param conn_id: connection id
+        :type conn_id: str
+        """
+        secret_id = self.build_secret_id(conn_id=conn_id)
+        # always return the latest version of the secret
+        secret_version = "latest"

Review comment:
       Hello. I'm Kamil from Polidea. We are a Google partner and we are building many integrations for Google services at the request of [Cloud Composer](https://cloud.google.com/composer).
   
   We have an abstraction layer that does not provide for this possibility, but I think we can introduce. special parameter syntax that lets you reference a specific version. 
   
   But I will explain the small context of how this change works so that you can make better design decisions. In previous versions of Airflow, all data was stored in a database (this behavior may have been overwritten by environment variables, so you can also store secret data in env var).
   
   The user selects the connection using the operator parameter. The following example will use connections with ID = `'my-company-id``.
   ```
       download_file = GCSToLocalOperator(
           task_id="download_file",
           object_name=BUCKET_FILE_LOCATION,
           bucket=BUCKET_1,
           filename=PATH_TO_SAVED_FILE,
           gcp_conn_id='my-company-id`
       )
   ```
   Please note that the user does not specify the type of backend secret. It is a universal mechanism and this data may come from a database, from environment variables or from another service.
   
   What do you think so that the user can define the connection version after the colon? The sample call will then look like this.
   ```
       download_file = GCSToLocalOperator(
           task_id="download_file",
           object_name=BUCKET_FILE_LOCATION,
           bucket=BUCKET_1,
           filename=PATH_TO_SAVED_FILE,
           gcp_conn_id='my-company-id:2`
       )
   ```
   It won't be a perfect solution, but I think it's easy to implement and easy to use. 
   




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