stream index http://images.maas.io/ephemeral-v3/daily/streams/v1/com.ubuntu.maas:daily:centos-bases-download.json, only contains centos 6.6 and centos 7.0, but not centos 8.
stream index http://images.maas.io/ephemeral-v3/daily/streams/v1/com.ubuntu.maas:daily:centos-bases-download.json, only contains centos 6.6 and centos 7.0, but not centos 8.