Simplified explaination of AWS tutorial on API gateway as S3 proxy.

1. /: GET gives list of all buckets
2. /{folder}: GET PUT DELETE for buckets
3. /{filder}/{item}: GET PUT DELETE HEAD for items in bucket

1. Create IAM role for API gateway. Then attach s3fullaccess policy to it.
2. Add resources and methods as mentioned above.
3. During creation

integration type: AWS service>s3
HTTP method: PUT GET DELETE(accordingly)
Path override for each method depends on its resource. {folder}/{item} will be mapped to {bucket}/{object}:

1. Resource /: /
2. Resource /{folder}: {bucket} 
3. Resource /{folder}/{item}: {bucket}/{object}

4. Path mappings

object -> method.request.path.item (only for resource #3)
bucket -> method.request.path.folder (for resource #2 and #3)

5. Header mappings(resource #2 and #3)
   Most s3 parameters like meta are passed through headers.

x-amz-acl -> 'authenticated-read' Content-Type -> method.request.header.Content-Type

Body can have text or binary. URL specifies bucket and object name. To enable binary add / in settings>binary media. If IAM was used to authenticate API then add authorization>AWS signature

https://xn2nuhcvxd.execute-api.us-east-1.amazonaws.com/dev/demobucket/bible.jpeg