Cloud images (cloud-images)

Ubuntu
# allow root login
cp /home/ubuntu/.ssh/authorized_keys /root/.ssh/authorized_keys
https://cloud-images.ubuntu.com/releases/
https://cloud-images.ubuntu.com/minimal/releases/
# latest
https://cloud-images.ubuntu.com/trusty/current/trusty-server-cloudimg-amd64-disk1.img
https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-disk1.img
https://cloud-images.ubuntu.com/bionic/current/bionic-server-cloudimg-amd64.img
https://cloud-images.ubuntu.com/cosmic/current/cosmic-server-cloudimg-amd64.img
https://cloud-images.ubuntu.com/disco/current/disco-server-cloudimg-amd64.img

Windows
https://cloudbase.it/windows-cloud-images/#download

RedHat
https://access.redhat.com/downloads/content/479/ver=/rhel---8/8.1/x86_64/product-software
https://access.redhat.com/downloads/content/69/ver=/rhel---7/7.7/x86_64/product-software

CentOS
https://cloud.centos.org/centos/
# latest
https://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud.qcow2

Fedora Atomic
https://mirrors.dotsrc.org/fedora-buffet/alt/atomic/stable/?C=M&O=D

CirrOS
# credentials
user: cirros
pass: gocubsgo
http://download.cirros-cloud.net/

# direct download
http://download.cirros-cloud.net/0.3.5/cirros-0.3.5-x86_64-disk.img
http://download.cirros-cloud.net/0.4.0/cirros-0.4.0-x86_64-disk.img

Update script

IMAGES="
https://cloud-images.ubuntu.com/minimal/daily/bionic/current/bionic-minimal-cloudimg-amd64.img
https://cloud-images.ubuntu.com/minimal/daily/eoan/current/eoan-minimal-cloudimg-amd64.img
"
for IMAGE in ${IMAGES}; do
    echo "Download ${IMAGE}..."
    wget -q ${IMAGE} -O ~/Downloads/iso/${IMAGE##*/}
done