how to install kaltura-server through command line, i use

echo y | yum install kaltura-server" but it shows like this

Total size: 1.1 G
Is this ok [y/N]: Downloading Packages:
warning: rpmts_HdrFromFdno: Header V4 RSA/SHA1 Signature, key ID ba443ef2: NOKEY

Refusing to automatically import keys when running unattended.
Use “-y” to override.

When using this through package resource,it installs but showing expiration time and get failed ,when seeing it shows yumdump gets expired of 900sec
Can any one have ides.