RDO provides a lot of images for OpenStack platform, but when uploading CentOS-7 image to Glance and launch an instance from the image, it requires the password to login the instance even with the key pair file. It is very wired, and I did not find the cause.
The solution is that when launching the instance, add the following script to the customization script panel in the Configuration selection.
1 | !/bin/sh |