Batch install RPM packages from .tar.gz file on CentOS

Question

How can I install a large group of .rpm packages that are compressed in a .tar.gz file?

Context: I am using Docker to build a CentOS 7 container and was provided a .tar.gz file containing many .rpm packages. These packages are dependencies for a program I would be running within the container. I would like a way to install all of these packages without needing to install them one by one (untar and 'rpm -ivh pkg1.rpm pkg2.rpm ...').

Solution

You have to untar the file and the install them with rpm

tar xfz file.tar.gz
rpm -i *rpm

There is no way for rpm to install RPMs from standard input.

Otherwise there is a archivemount to mount the tarball (see https://superuser.com/questions/265772/is-it-possible-to-mount-a-tar-file).