I'm planning to subscribe to a web provider of Baremetals/VMs in order to practice the installation/upgrading of OCP.
I'm wondering what do you usually use for this kind of practices ? Any advice ?
As OpenShift is installed via Ansible playbooks it doesn't really matter whether you'll install it on baremetal or on VMs. I'd recommend to use Vagrant or Terraform + use cloud provider API to automate creation/deletion of VMs. This would save you a lot of time. Take a look at this video for example: https://www.youtube.com/watch?v=aqXSbDZggK4&t=8s
Funny you mention Vagrant. It's very difficult to find good information about utilizing Vagrant on RHEL (with libvirt) to stand up RHEL VMs. After much searching, I found this:
Alessandro Arrichiello is a Red Hatter based in Italy.
This doesn't talk about installing vagrant. You can of course download the RPM directly from vagrantup.com . I think you can get vagrant from Red Hat repos (Red Hat Software Collections?), just haven't found a good way yet. [rhel-server-rhscl-7-rpms has vagrant plugins available for Eclipse, but can't quite find vagrant...]
I have documented how to install OpenShift manually in 2 articles on Red Hat's Services blog:
These articles include 6 videos to show you step by step creating your own domain, TLS certificates, a DNS server and OpenShift for valid HTTPS connections to the OpenShift web console and all routes.