First, svirt_sandbox_file_t is superseded by container_t
But more importantly, the following Salt block fails on Equatower:
selinux_context_etherpad_data: selinux.fcontext_policy_present: - name: /srv/etherpad - sel_type: svirt_sandbox_file_t selinux_context_etherpad_data_applied: selinux.fcontext_policy_applied: - name: /srv/etherpad