pillar/shells/init.sls
shells:
    {% if grains['os_family'] == 'FreeBSD' -%}
      shell_bash: '/usr/local/bin/bash'
    {% else -%}
      shell_bash: '/bin/bash'
    {% endif -%}

pillar/backuppc.sls
users:
  backuppc:
    fullname: BackupPC Service
    password: '*'
    enforce_password: True
    empty_password: False
    hash_password: False
    sudouser: True
    sudo_rules:
      - ALL = NOPASSWD:/usr/bin/rsync, /bin/tar
    shell: {{ pillar['shells']['shell_bash'] }}
    prime_group:
      name: nogroup
    ssh_auth_sources:
      - salt://users/files/backuppc/backuppc.pub