The file server is based on webdav. It supports file download, upload, and folder creation. But uploading file and creating folder needs basic authentication.
$ oc login https://api.ocp4.prod.psi.redhat.com:6443 --token=<openshift token>
$ oc project virt-qe-3rd
$ oc process -f file-server-buildconfig-template.yaml | oc apply -f -
$ curl -o <file_name> http://file-server-virt-qe-3rd.apps.ocp4.prod.psi.redhat.com/<file_path + file_name>
$ curl --basic --user '3rd-user:redhat' -T <upload_file> http://file-server-virt-qe-3rd.apps.ocp4.prod.psi.redhat.com/
$ curl --basic --user '3rd-user:redhat' -X DELETE http://file-server-virt-qe-3rd.apps.ocp4.prod.psi.redhat.com/<file_path + file_name>
$ curl --basic --user '3rd-user:redhat' -X MKCOL http://file-server-virt-qe-3rd.apps.ocp4.prod.psi.redhat.com/<folder>/