Use boto3 for S3 fileadmin

`boto` has long since been deprecated and replaced by `boto3`. This
patch moves over to using the new `boto3` library for interacting with
the S3 bucket.

This is a breaking change because the interface for S3FileAdmin also
changes - rather than taking the AWS keys directly, it now takes a
boto.client('s3') instance.

doc/advanced.rst

@@ -162,14 +162,14 @@ can use it by adding a FileAdmin view to your app::
 
 
 FileAdmin also has out-of-the-box support for managing files located on a Amazon Simple Storage Service
-bucket. To add it to your app::
+bucket using a `boto3 client <https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html#boto3.session.Session.client>`_. To add it to your app::
 
     from flask_admin import Admin
     from flask_admin.contrib.fileadmin.s3 import S3FileAdmin
 
     admin = Admin()
 
-    admin.add_view(S3FileAdmin('files_bucket', 'us-east-1', 'key_id', 'secret_key')
+    admin.add_view(S3FileAdmin(boto3.client('s3'), 'files_bucket'))
 
 You can disable uploads, disable file deletion, restrict file uploads to certain types, etc.
 Check :mod:`flask_admin.contrib.fileadmin` in the API documentation for more details.

doc/changelog.rst

@@ -1,6 +1,13 @@
 Changelog
 =========
 
+2.0.0a2
+-------
+
+Breaking changes:
+
+* Use of the `boto` library has been replaced by `boto3`. S3FileAdmin and S3Storage now accept a `boto3.client('s3')` instance rather than AWS access+secret keys directly.
+
 2.0.0a1
 -------
 

examples/s3/README.md

@@ -0,0 +1,23 @@
+# S3 Example
+
+Flask-Admin example for an S3 bucket.
+
+To run this example:
+
+1. Clone the repository and navigate to this example::
+
+    git clone https://github.com/pallets-eco/flask-admin.git
+    cd flask-admin/examples/s3
+
+2. Create and activate a virtual environment::
+
+    python -m venv venv
+    source venv/bin/activate
+
+3. Install requirements::
+
+    pip install -r requirements.txt
+
+4. Run the application::
+
+    python app.py

examples/s3/__init__.py

@@ -0,0 +1,5 @@
+from flask import Flask
+from flask_admin import Admin
+
+app = Flask(__name__)
+admin = Admin(app)

examples/s3/app.py

@@ -0,0 +1,55 @@
+import os
+from io import BytesIO
+
+import boto3
+from flask import Flask
+from flask_admin import Admin
+from flask_admin.contrib.fileadmin.s3 import S3FileAdmin
+from testcontainers.localstack import LocalStackContainer
+
+app = Flask(__name__)
+app.config["SECRET_KEY"] = "secret"
+admin = Admin(app)
+
+if __name__ == "__main__":
+    with LocalStackContainer(image="localstack/localstack:latest") as localstack:
+        s3_endpoint = localstack.get_url()
+        os.environ["AWS_ENDPOINT_OVERRIDE"] = s3_endpoint
+
+        # Create S3 client
+        s3_client = boto3.client(
+            "s3",
+            aws_access_key_id="test",
+            aws_secret_access_key="test",
+            endpoint_url=s3_endpoint,
+        )
+
+        # Create S3 bucket
+        bucket_name = "bucket"
+        s3_client.create_bucket(Bucket=bucket_name)
+
+        s3_client.upload_fileobj(BytesIO(b""), "bucket", "some-directory/")
+
+        s3_client.upload_fileobj(
+            BytesIO(b"abcdef"),
+            "bucket",
+            "some-file",
+            ExtraArgs={"ContentType": "text/plain"},
+        )
+
+        s3_client.upload_fileobj(
+            BytesIO(b"abcdef"),
+            "bucket",
+            "some-directory/some-file",
+            ExtraArgs={"ContentType": "text/plain"},
+        )
+
+        # Add S3FileAdmin view
+        admin.add_view(
+            S3FileAdmin(
+                bucket_name=bucket_name,
+                s3_client=s3_client,
+            )
+        )
+
+        app.run(debug=True)

examples/s3/requirements.txt

@@ -0,0 +1,2 @@
+../..[s3]
+testcontainers

examples/sqla/admin/__init__.py

@@ -22,8 +22,4 @@ def get_locale():
 babel = Babel(app, locale_selector=get_locale)
 
 
-# Initialize babel
-babel = Babel(app, locale_selector=get_locale)
-
-
 import admin.main  # noqa: F401, E402