Templates to provision multi-homed systems?

Stefan_Lasiewski · March 9, 2019, 2:53am

Hi folks,

The nodes in our cluster have separate provisioning and production networks. The provisioning network is on a private address space like 192.168.x.y, which has one gateway to allow access to the public OS mirrors. The public network is on a regular IPv4 routeable network.

I’ve provisioned a couple test CentOS & Ubuntu VMs, and I belive that the default provisioning templates only seem able to provision one NIC per host. If I create two NICs on a VM, for example, only one is created on the host.

What’s a good way to provision a host with two or NICs?

lzap · March 15, 2019, 3:28pm

Our templates only configures provisioning NIC for provisioning phase, but in the end they drop configuration for all NICs:

github.com

theforeman/community-templates/blob/develop/provisioning_templates/snippet/kickstart_networking_setup.erb

<%#
name: kickstart_networking_setup
model: ProvisioningTemplate
snippet: true
model: ProvisioningTemplate
kind: snippet
-%>
<%- bonded_interfaces = [] -%>
<%- bonding_interfaces = [] -%>
<%- @host.bond_interfaces.each do |bond| -%>
<%-   bonding_interfaces.push(bond.identifier) -%>
<%=   "# #{bond.identifier} interface" %>
<%=   snippet('kickstart_ifcfg_get_identifier_names', :variables => { :identifier => bond.identifier }) %>
<%-   ifcfg = snippet('kickstart_ifcfg_bond_interface', :variables => {
                        :interface => bond,
                        :subnet => bond.subnet,
                        :subnet6 => bond.subnet6,
                        :dhcp => bond.subnet.nil? ? false : bond.subnet.dhcp_boot_mode? }) -%>
<%=   save_to_file('/etc/sysconfig/network-scripts/ifcfg-$sanitized_real', ifcfg) %>

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Stefan_Lasiewski · March 15, 2019, 10:15pm

Our templates only configures provisioning NIC for provisioning phase, but in the end they drop configuration for all NICs:

On CentOS 7, it seems to work.

For Ubuntu 18.04, Foreman places a similar configuration under /etc/network/interfaces:

github.com

theforeman/community-templates/blob/develop/provisioning_templates/snippet/preseed_networking_setup.erb#L16


description: this will configure your host networking, it configures your primary interface as well
as other configures NICs. It supports physical, VLAN and Alias interfaces. It's intended to be
called in your preseed finish template.
%>
<% host_subnet = @host.subnet -%>
<% host_dhcp = host_subnet.nil? ? false : host_subnet.dhcp_boot_mode? -%>
<% host_subnet6 = @host.subnet6 -%>
<% host_dhcp6 = host_subnet6.nil? ? false : host_subnet6.dhcp_boot_mode? -%>


real=`ip -o link | awk '/<%= @host.mac -%>/ {print $2;}' | sed s/://`
cat << EOF > /etc/network/interfaces
#loopback
auto lo
iface lo inet loopback


#<%= @host.primary_interface.identifier %>
auto $real
allow-hotplug $real
iface $real inet <%= host_dhcp ? 'dhcp' : 'static' %>
<% unless host_dhcp -%>
address <%= @host.ip %>

But it appears that Ubuntu 18.04 is ignoring /etc/network/interfaces by default, since it uses Netplan instead.

I do see a PR to implement Netplan at https://github.com/theforeman/community-templates/pull/545 . Currently, that PR only adds a single interface. If I can find time I’ll contribute a fix.

Stefan_Lasiewski · March 15, 2019, 10:59pm

And just to clarify (and for posterity), Ubuntu had a network configuration in Netplan already. I think this came straight from the distro itself:

root@host1:~# cat /etc/netplan/01-netcfg.yaml  
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    ens160:
      dhcp4: yes
root@host1:~#