fix(create_bucket): avoid S3 InvalidLocationConstraint error

calling create_bucket(bucket_name, region="us-east-1") yields the
following error:

boto.exception.S3ResponseError: S3ResponseError: 400 Bad Request
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>InvalidLocationConstraint</Code>
<Message>The specified location-constraint is not valid</Message>
<LocationConstraint>us-east-1</LocationConstraint>...</Error>

based on the comments in boto/boto3#125 this commit omits the region
kwarg to the create_bucket() call when `s3.region` is set to "us-east-1"

rootfs/bin/create-bucket

@@ -25,7 +25,11 @@ if os.getenv('REGISTRY_STORAGE') == "s3" and os.getenv('REGISTRY_STORAGE_S3_BACK
     conn = boto.s3.connect_to_region(region)
 
     if not bucket_exists(conn, bucket_name):
-        conn.create_bucket(bucket_name, location=region)
+        if region == "us-east-1":
+            # use "US Standard" region. workaround for https://github.com/boto/boto3/issues/125
+            conn.create_bucket(bucket_name)
+        else:
+            conn.create_bucket(bucket_name, location=region)
 
 elif os.getenv('REGISTRY_STORAGE') == "gcs":
     scopes = ['https://www.googleapis.com/auth/devstorage.full_control']

rootfs/bin/create_bucket

@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+
+import os
+
+import boto.s3
+import json
+import swiftclient
+from boto import config as botoconfig
+from boto.exception import S3CreateError
+from boto.s3.connection import S3Connection, OrdinaryCallingFormat
+from oauth2client.service_account import ServiceAccountCredentials
+from gcloud.storage.client import Client
+from gcloud import exceptions
+from azure.storage.blob import BlobService
+
+def bucket_exists(conn, name):
+    bucket = conn.lookup(name)
+    if not bucket:
+        return False
+    return True
+
+bucket_name = os.getenv('BUCKET_NAME')
+region = os.getenv('AWS_REGION')
+
+if os.getenv('DATABASE_STORAGE') == "s3":
+    conn = boto.s3.connect_to_region(region)
+    if not bucket_exists(conn, bucket_name):
+        try:
+            if region == "us-east-1":
+                # use "US Standard" region. workaround for https://github.com/boto/boto3/issues/125
+                conn.create_bucket(bucket_name)
+            else:
+                conn.create_bucket(bucket_name, location=region)
+        # NOTE(bacongobbler): for versions prior to v2.9.0, the bucket is created in the default region.
+        # if we got here, we need to propagate "us-east-1" into WALE_S3_ENDPOINT because the bucket
+        # exists in a different region and we cannot find it.
+        # TODO(bacongobbler): deprecate this once we drop support for v2.8.0 and lower
+        except S3CreateError as err:
+            if region != 'us-east-1':
+                print('Failed to create bucket in {}. We are now assuming that the bucket was created in us-east-1.'.format(region))
+                with open(os.path.join(os.environ['WALE_ENVDIR'], "WALE_S3_ENDPOINT"), "w+") as file:
+                    file.write('https+path://s3.amazonaws.com:443')
+            else:
+                raise
+
+elif os.getenv('DATABASE_STORAGE') == "gcs":
+    scopes = ['https://www.googleapis.com/auth/devstorage.full_control']
+    credentials = ServiceAccountCredentials.from_json_keyfile_name(os.getenv('GOOGLE_APPLICATION_CREDENTIALS'), scopes=scopes)
+    with open(os.getenv('GOOGLE_APPLICATION_CREDENTIALS')) as data_file:
+        data = json.load(data_file)
+    conn = Client(credentials=credentials, project=data['project_id'])
+    exists = True
+    try:
+        conn.get_bucket(bucket_name)
+    except exceptions.NotFound:
+        exists = False
+    except:
+        raise
+    if not exists:
+        conn.create_bucket(bucket_name)
+
+elif os.getenv('DATABASE_STORAGE') == "azure":
+    conn = BlobService(account_name=os.getenv('WABS_ACCOUNT_NAME'), account_key=os.getenv('WABS_ACCESS_KEY'))
+    #It doesn't throw an exception if the container exists by default(https://github.com/Azure/azure-storage-python/blob/master/azure/storage/blob/baseblobservice.py#L504).
+    conn.create_container(bucket_name)
+
+elif os.getenv('DATABASE_STORAGE') == "swift":
+    conn = swiftclient.Connection(
+        user=os.getenv('SWIFT_USER'),
+        key=os.getenv('SWIFT_PASSWORD'),
+        authurl=os.getenv('SWIFT_AUTHURL'),
+        auth_version=os.getenv('SWIFT_AUTH_VERSION'),
+        tenant_name=os.getenv('SWIFT_TENANT')
+    )
+    # swift also does not throw exception if container already exists.
+    conn.put_container(os.getenv('BUCKET_NAME'))
+
+else:
+    botoconfig.add_section('s3')
+    botoconfig.set('s3', 'use-sigv4', 'True')
+    botoconfig.add_section('Boto')
+    botoconfig.set('Boto', 'is_secure', 'False')
+    conn = S3Connection(
+        host=os.getenv('S3_HOST'),
+        port=int(os.getenv('S3_PORT')),
+        calling_format=OrdinaryCallingFormat())
+    # HACK(bacongobbler): allow boto to connect to minio by changing the region name for s3v4 auth
+    conn.auth_region_name = os.getenv('AWS_REGION')
+    if not bucket_exists(conn, bucket_name):
+        conn.create_bucket(bucket_name)