you should specify s3 access key, secret key and endpoint
with ACCESS_KEY, SECRET_KEY, and ENDPOINT build args respectively.
In order to use a proxy for plugin installation, provide the http_proxy and https_proxy build-args. (it will be used by curl)
Also, you can set PACKAGES build-arg to specify what extra packages to be installed in the docker image.
The default value of PACKAGES is "net-tools lsof".