https://mirrors.sohu.com/ubuntu-cloud-images/releases/14.04.2/release-20170104/?C=N&O=D
Index of /ubuntu-cloud-images/releases/14.04.2/release-20170104/
index ofcloud imagesubuntu
https://cloud-images.ubuntu.com/releases/server/server/14.04/release-20170104/?C=M;O=A
Index of /releases/server/server/14.04/release-20170104
index ofreleasesserver