From the installation tutorial:

The following minimum requirements should support a proof-of-concept environment with core services and several CirrOS instances:

Controller Node: 1 processor, 4 GB memory, and 5 GB storage

Compute Node: 1 processor, 2 GB memory, and 10 GB storage

See also https://docs.openstack.org/install-gu....

In my experience, a virtual machine with a single vCPU, 8GB RAM, 50GB disk is sufficient for a single-node deployment using Devstack or Packstack. I have never tried a physical machine, but I don’t see how it should be different.

The Kolla, OSA, Juju Charms and Tripleo projects have their own recommendations.

you can view also that but you must have 5 nodes:

https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/index.html (https://docs.openstack.org/project-de...)