How to use different uploaders in CKAN (local & cloud)

Question

I have multiple workspaces on a single CKAN installation. I want the resources of some workspaces to be stored locally to my server and the resources of other ones to be stored on AWS. For uploading to AWS, I am using https://github.com/open-data/ckanext-cloudstorage After setting it up, each upload goes to AWS and nothing local.

I want CKAN (or a plugin) to decide when to upload based on the workspace. I have written this code, in a custom plugin

   
    import ckan
    import ckan.lib.uploader as uploader
    import ckan.plugins as plugins
    import ckan.plugins.toolkit as toolkit
    from pprint import pprint

    from ckanext.cloudstorage import storage

    c = toolkit.c
    class MyCustomPlugin(plugins.SingletonPlugin):            

        #IUploader
        plugins.implements(plugins.IUploader)

        def get_resource_uploader(self, data_dict):

            catalogs_string = toolkit.config.get(
                'ckanext.myplugin.catalogs_to_upload_to_cloud_storage', '')
            catalogs = catalogs_string.split()

            context = {'model': ckan.model, 'session': ckan.model.Session,
               'user': c.user}

            package = toolkit.get_action('package_show')(context, {"id":data_dict['package_id']})

            organization = toolkit.get_action('organization_show')(context, {"id":package['organization']['id']})
            groups = organization['groups']
            upload_to_aws = False
            for g in groups:
                for cat in catalogs:
                    #print(g['name'])
                    if g['name'] == cat:
                        upload_to_aws = True
                        break

            #package = ckanGet.package_show(c, {"package_id":resource['package_id']})
            #print(package)
            #print(organization)
            #print(catalogs)
            print(upload_to_aws)

            if upload_to_aws == True:
                return storage.ResourceCloudStorage(data_dict)
            else:
                return uploader.ResourceUpload(data_dict)

        #for upload of files which are not resource, use default upload (local to the ckan installation)
        def get_uploader(self, upload_to, old_filename = None):
            return uploader.Upload(upload_to, old_filename)

On the config file (ckan.ini), I have added something like

ckanext.myplugin.catalogs_to_upload_to_cloud_storage = workspace1 workspace2

Let's suppose I have 4 workspaces. I want workspace1 and workspace2 to be uploaded to aws and workspace3 and workspace4 locally.

The plugin I have written does not work. its function get_resource_uploader() is being called, since I see the prints on the terminal. The method does its job, but the returned values seems to be skipped.

Any comment / suggestion / solution? I am working on CKAN 2.9.5

Thank you so much