Add google cloud storage samples using gcloud. (#397)

Author: hohaichi

storage/gcloud/customer_supplied_keys.py

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+#!/usr/bin/env python
+
+# Copyright 2016 Google Inc. All rights reserved.
+#
+# Licensed 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.
+"""Command-line sample app demonstrating customer-supplied encryption keys.
+
+This sample demonstrates uploading an object while supplying an encryption key,
+and retrieving that object's contents using gcloud API.  The sample uses
+the default credential and project.  To review their values, run this command:
+    $ gcloud info
+
+This sample is used on this page:
+    https://cloud.google.com/storage/docs/encryption#customer-supplied
+
+For more information, see the README.md under /storage.
+"""
+
+import argparse
+import base64
+import filecmp
+import os
+import tempfile
+
+from gcloud import storage
+
+# An AES256 encryption key.  It must be exactly 256 bits (32 bytes).  You can
+# (and should) generate your own encryption key.  os.urandom(32) is a good way
+# to accomplish this with Python.
+#
+# Although these keys are provided here for simplicity, please remember
+# that it is a bad idea to store your encryption keys in your source code.
+ENCRYPTION_KEY = os.urandom(32)
+
+
+def upload_object(storage_client,
+                  bucket_name,
+                  filename,
+                  object_name,
+                  encryption_key):
+    """Uploads an object, specifying a custom encryption key.
+
+    Args:
+        storage_client: gcloud client to access cloud storage
+        bucket_name: name of the destination bucket
+        filename: name of file to be uploaded
+        object_name: name of resulting object
+        encryption_key: encryption key to encrypt the object,
+                        either 32 raw bytes or a string of 32 bytes.
+    """
+    bucket = storage_client.get_bucket(bucket_name)
+    blob = bucket.blob(object_name)
+    with open(filename, 'rb') as f:
+      blob.upload_from_file(f, encryption_key=encryption_key)
+
+
+def download_object(storage_client,
+                    bucket_name,
+                    object_name,
+                    filename,
+                    encryption_key):
+    """Downloads an object protected by a custom encryption key.
+
+    Args:
+        storage_client: gcloud client to access cloud storage
+        bucket_name: name of the source bucket
+        object_name: name of the object to be downloaded
+        filename: name of the resulting file
+        encryption_key: the encryption key that the object is encrypted by,
+                        either 32 raw bytes or a string of 32 bytes.
+    """
+    bucket = storage_client.get_bucket(bucket_name)
+    blob = bucket.blob(object_name)
+    with open(filename, 'wb') as f:
+        blob.download_to_file(f, encryption_key=encryption_key)
+
+
+def main(bucket, filename):
+    storage_client = storage.Client()
+    print('Uploading object gs://{}/{} using encryption key (base64 formatted)'
+          ' {}'.format(bucket, filename, base64.encodestring(ENCRYPTION_KEY)))
+    upload_object(storage_client, bucket, filename, filename, ENCRYPTION_KEY)
+    print('Downloading it back')
+    with tempfile.NamedTemporaryFile(mode='w+b') as tmpfile:
+        download_object(storage_client, bucket, object_name=filename,
+                        filename=tmpfile.name, encryption_key=ENCRYPTION_KEY)
+        assert filecmp.cmp(filename, tmpfile.name), \
+            'Downloaded file has different content from the original file.'
+    print('Done')
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(
+            description=__doc__,
+            formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument('bucket', help='Your Cloud Storage bucket.')
+    parser.add_argument('filename', help='A file to upload and download.')
+
+    args = parser.parse_args()
+
+    main(args.bucket, args.filename)

storage/gcloud/customer_supplied_keys_test.py

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+# Copyright 2016, Google, Inc.
+# Licensed 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.
+
+import re
+
+from customer_supplied_keys import main
+
+
+def test_main(cloud_config, capsys):
+    main(cloud_config.storage_bucket, __file__)
+    out, err = capsys.readouterr()
+
+    assert not re.search(r'Downloaded file [!]=', out)
+    assert re.search(r'Uploading.*Downloading.*Done', out, re.DOTALL)