Libvirt Multi VM Support

[ssasso]

Following discussion in #124 we may want to support "Multi VM" nodes also on libvirt topologies (containerlab is already supporting it - thanks @jbemmel for pointing that out).
This could be useful to run vQFX and vMX in netsim-tools.

An example Vagrantfile for vQFX is the following one:

Vagrant.configure("2") do |config|

  # RE is also where the data ports are connected
  config.vm.define "re" do |re|
    re.vm.provider :libvirt do |domain|
      domain.management_network_mac = "08-4F-A9-00-00-01"
      domain.qemu_use_session = false
    end
    
    re.vm.box = "juniper/vqfx10k-re"
    re.vm.guest = :freebsd
    re.vm.boot_timeout = 360
    re.ssh.insert_key = false
    
    re.vm.synced_folder '.', '/vagrant', disabled: true
    
    re.vm.provider :libvirt do |domain|
      domain.cpus = 2
      domain.memory = 2048
      domain.nic_model_type = "virtio-net-pci"
    end
    
    # First Virtual Network, link to PFE
    re.vm.network :private_network,
                  :libvirt__tunnel_type => "udp",
                  :libvirt__tunnel_local_ip => "127.1.254.1",
                  :libvirt__tunnel_local_port => "10001",
                  :libvirt__tunnel_ip => "127.1.254.2",
                  :libvirt__tunnel_port => "10001",
                  :libvirt__iface_name => "vgif_re_1",
                  auto_config: false

    # Additional UNUSED PORT
    re.vm.network :private_network,
                  :libvirt__tunnel_type => "udp",
                  :libvirt__tunnel_local_ip => "127.1.254.1",
                  :libvirt__tunnel_local_port => "10099",
                  :libvirt__tunnel_ip => "127.1.254.2",
                  :libvirt__tunnel_port => "10099",
                  :libvirt__iface_name => "vgif_re_2",
                  auto_config: false

    # Dataplane Ports are here
    (1..5).each do |seg_id|
        re.vm.network :private_network,
                  :libvirt__tunnel_type => "udp",
                  :libvirt__tunnel_local_ip => "127.1.22.1",
                  :libvirt__tunnel_local_port => "1000#{seg_id}",
                  :libvirt__tunnel_ip => "127.1.22.2",
                  :libvirt__tunnel_port => "1000#{seg_id}",
                  :libvirt__iface_name => "vgif_re_dp#{seg_id}",
                  auto_config: false
    end
  end

  # PFE
  config.vm.define "pfe" do |pfe|
    pfe.vm.provider :libvirt do |domain|
      domain.qemu_use_session = false
    end
    
    pfe.vm.box = "juniper/vqfx10k-pfe"
    pfe.vm.guest = :freebsd
    pfe.vm.boot_timeout = 360
    pfe.ssh.insert_key = false
    pfe.ssh.username = "tc"
    
    pfe.vm.synced_folder '.', '/vagrant', disabled: true
    
    pfe.vm.provider :libvirt do |domain|
      domain.cpus = 2
      domain.memory = 2048
      domain.nic_model_type = "e1000"
    end
    
    # First Virtual Network, link to RE
    pfe.vm.network :private_network,
                  :libvirt__tunnel_type => "udp",
                  :libvirt__tunnel_local_ip => "127.1.254.2",
                  :libvirt__tunnel_local_port => "10001",
                  :libvirt__tunnel_ip => "127.1.254.1",
                  :libvirt__tunnel_port => "10001",
                  :libvirt__iface_name => "vgif_pfe_1",
                  auto_config: false
  end

end

Note: depending on the VM kind itself, the data ports are connected to the RE or to the PFE (i.e. vMX and vQFX have different behaviours)

[ipspace]

Create a proof-of-concept QDS in qfx branch:

• Define PFE first (because it has no external links)
• End VM definition, start new VM definition within the VM domain template
• Add RE parameters
• Vagrantfile.j2 will add MAC address and links

If it works, then I'll polish it to add a provider-specific parameter (ex: provider_template) meaning "for this VM execute a full-blown template that will do its own stuff", probably after #96.

Just in case: QDS == Quick and Dirty Solution

[ipspace]

Forget about that QDS, aac8a03 adds support for "raw" Vagrantfile template -- a device-specific template that bypasses the standard way of configuring VMs. You could take the same vQFX setup, copy it into vqfx-raw.j2 and adapt it to use our templates for data-plane interfaces.

[ipspace]

The functionality is there if we ever need it, vMX is implemented as a container in #670 -- it requires multiple disks and that could get really messy with Vagrant boxes.