vagrant hostmanager versus public_interface

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/xenial64"

  config.vm.network "public_network", use_dhcp_assigned_default_route: true, bridge: "en0: Wi-Fi (AirPort)"

  config.hostmanager.enabled = true
  config.hostmanager.manage_host = true
  config.hostmanager.manage_guest = true
  config.hostmanager.ignore_private_ip = false
  config.hostmanager.include_offline = true
  
  # custom ip resolver for public network with dhcp
  config.hostmanager.ip_resolver = proc do |vm|
     ip = nil
  
    if vm.state.id == :running
      if vm.id
        property_value = `VBoxManage guestproperty get #{vm.id} "/VirtualBox/GuestInfo/Net/1/V4/IP"`.strip
        ip = property_value.split()[1] unless property_value == 'No value set!'
      end
  
      if ip.nil?
        ifconfig_value = ''
        vm.communicate.execute("ifconfig eth1; exit 0") do |type, data|
          ifconfig_value << data if type == :stdout
        end
        ip = (ip = /^\s*inet .*?(\d+\.\d+\.\d+\.\d+)\s+/.match(ifconfig_value)) && ip[1]
      end
    end
    ip
  end
  
  config.vm.provision :hostmanager

  config.vm.define :vm1 do |machine|
    machine.vm.hostname = 'vm1'
    machine.hostmanager.aliases = %w(vm1.local)
  end

  config.vm.define :vm2 do |machine|
    machine.vm.hostname = 'vm2'
    machine.hostmanager.aliases = %w(vm2.local)
  end
end