systemd_network resource does not allow multiple addresses

[schrd]

A network unit file can specify multiple static addresses for an interface. Even mixing of IPv4 and IPv6 addresses is possible. A working example would look like

[Match]
Name = en* eth*

[Network]
DHCP = no
Address = 192.168.121.4/24
Address = 192.168.121.2/24

If I specify a systemd_network resource such as

systemd_network 'static' do
  match_name 'en* eth*'
  network_address ['192.168.121.4/24', '192.168.121.2/24']
end

produces an invalid file which systemd-networkd rejects:

[Match]
Name = en* eth*

[Network]
DHCP = no
Address = 192.168.121.4/24 192.168.121.2/24

To me it looks like SystemdCookbook::Mixin::PropertyHashConversion::InstanceMethods#option_value is causing the issue.

The systemd_unit resource correctly converts arrays to multiple entries:

u = systemd_unit 'test.service' do
  content({
    Unit: {
      Description: ['Foo', 'bar']
    }
  })
end

file "/tmp/test.ini" do
  content u.to_ini
end

produces

[Unit]
Description = Foo
Description = bar

[nathwill]

thanks for the report @schrd :)

some variation of this comes up every once in a while and i'm still not super sure what a workable solution looks like... option_value is definitely designed to convert arrays into space-separated strings, because that's how systemd handles array-type arguments (e.g. Before=, After=, which take lists of units). for now, i think using the precursor property will let you inject an extra address field.

in the past, the way we've worked around the limitation has been to use drop-in resources or the precursor property when needing to provide the same directive more than once.

i'm open to any backwards-compatible suggestions!

[schrd]

@nathwill what do you think about using classes to differentiate between the two ways of handling arrays? See #138

[jklare]

@schrd I also ran into this issue while trying to assign multiple vlans on one interface. After playing around a little with different solutions i went for the "ruby is anarchy" one and defined it like this:

systemd_network 'eth0' do
  match_name 'eth0'
  network_vlan "eth0.2\nVLAN = eth0.8"
end

IMHO this is ugly, but still better than defining a switchcase for each possible argument to differentiate between the different styles that are accepted by systemd configs. Maybe this should rather be fixed in systemd.