Hypervisor machine

Hypervisor machine is the target machine where infrared’s virsh provisioner will create virtual machines and networks (using libvirt) to emulate baremetal infrastructure.

As such there are several specific requirements it has to meet.

Generally, It needs to have enough memory and disk storage to hold multiple decent VMs (each with GBytes of RAM and dozens of GB of disk). Also for acceptable responsiveness (speed of deployment/testing) just <4 threads or low GHz CPU is not a recommended choice (if you have old and weaker CPU than current mid-high end mobile phone CPU you may suffer performance wise - and so more timeouts during deployment or in tests).

Especially, for Ironic (TripleO) to control them, those libvirt VMs need to be bootable/controllable for iPXE provisioning. And also extra user has to exist, which can ssh in the hypervisor and control (restart…) libvirt VMs.

Note

infrared is attempting to configure or validate all (most) of this but it’s may be scattered across all provisiner/installer steps. Current infrared approach is stepped toeard direction to be more idempotent, and failures on previous runs shouldn’t prevent succesfull executinon of following runs.

What user has to provide:

  • have machine with sudoer user ssh access and enough resources, as minimum requirements for one VM are:
    • VCPU: 2|4|8
    • RAM: 8|16
    • HDD: 40GB+
    • in practice disk may be smaller, as they are thin provisioned, as long as you don’t force writing all the data (aka Tempest with rhel-guest instead of cirros etc)
  • RHEL-7.3 and RHEL-7.4 are tested, CentOS is also expected to work
    • may work with other distributions (best-effort/limited support)
  • yum repositories has to be preconfigured by user (foreman/…) before using infrared so it can install dependencies
    • esp. for infrared to handle ipxe-roms-qemu it requires either RHEL-7.{3|4}-server channel

What infrared takes care of:

  • ipxe-roms-qemu package of at least version 2016xxyy needs to be installed
  • other basic packages installed
    • libvirt, libguestfs{-tools,-xfs}, qemu-kvm, wget, virt-install
  • virtualization support (VT-x/AMD-V)
    • ideally with nested=1 support
  • stack user created with polkit privileges for org.libvirt.unix.manage
  • ssh key with which infrared can authenticate (created and) added for root and stack user, ATM they are handled differently/separately:
    • for root the infared/id_rsa.pub gets added to authorized_keys
    • for stack infrared/id_rsa_undercloud.pub is added to authorized_keys, created/added later during installation