Description of problem:
The network panel of the Anaconda GUI allows to create a bridged VLAN interface. The resulting ifcfg files looks good, but the resulting anaconda-ks.cfg doesn't allow to reproduce the network configuration.

Version-Release number of selected component (if applicable):
anaconda-29.19.0.41-1.el8_0.x86_64

How reproducible:


Steps to Reproduce:
1. Use the following kickstart directive (supposing ens3 is your parent device)
network  --bootproto=dhcp --device=bridge0 --ipv6=auto --bridgeslaves=ens3.100 --bridgeopts=priority=32768,stp=yes --no-activate
network  --bootproto=dhcp --device=ens3 --onboot=off --ipv6=auto --activate
network  --hostname=localhost.localdomain

2. Install a minimal server with this kickstart.

3. Observe the garbage connection which is created (not a VLAN and not enslaved)


Actual results:
# cat ifcfg-bridge0_slave_1
# Generated by parse-kickstart
TYPE="Ethernet"
NAME="bridge0 slave 1"
UUID="db232faa-7741-42af-a047-2b16fd91a44e"
ONBOOT="yes"
BRIDGE="bridge0"
DEVICE="ens2.100"

# ls /sys/class/net/bridge0/brif
==> nothing enslaved

Expected results:
# nmcli con show
NAME                 UUID                                  TYPE      DEVICE   
bridge0 slave 1      a98a9142-cffe-4100-81d2-c5bc4a7e18e0  vlan      ens3.100 
ens3                 d281553e-a52b-4254-9adc-f0390eea1098  ethernet  ens3     
Bridge connection 1  2c0aaf4c-a77f-4fce-a1e6-73ada5e53153  bridge    bridge0  

# ls /sys/class/net/bridge0/brif
ens3.100

# cat ifcfg-Bridge_connection_1 
STP=yes
BRIDGING_OPTS=priority=32768
TYPE=Bridge
NAME="Bridge connection 1"
DEVICE=bridge0
ONBOOT=yes
...

# cat ifcfg-bridge0_slave_1 
VLAN=yes
TYPE=Vlan
PHYSDEV=ens3
VLAN_ID=100
NAME="bridge0 slave 1"
DEVICE=ens3.100
ONBOOT=yes
BRIDGE=bridge0
...

Additional info:
I made a lot of tests, and it seems to be impossible to get this configuration working automatically. The most close result should be:

network  --bootproto=dhcp --device=ens2 --noipv6 --vlanid=100 --interfacename=ens2.100 --onboot=on --activate
network  --bootproto=dhcp --device=bridge0 --noipv6 --bridgeslaves=ens2.100 --bridgeopts=priority=32768,stp=yes --onboot=on --activate

But this doesn't work as expected:
-> The VLAN interface isn't enslaved
-> A garbage slave interface still remains

It can be easily workarounded in a 2nd time with the following commands:

# echo BRIDGE=bridge0 >> /etc/sysconfig/network-scripts/ifcfg-ens2.100

# ifup ens2.100
[  797.023870] bridge0: port 1(ens2.100) entered blocking state
[  797.025089] bridge0: port 1(ens2.100) entered disabled state
[  797.026845] device ens2.100 entered promiscuous mode
[  797.028420] device ens2 entered promiscuous mode
[  797.029773] bridge0: port 1(ens2.100) entered blocking state
[  797.031301] bridge0: port 1(ens2.100) entered listening state
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/7)
[  812.300352] bridge0: port 1(ens2.100) entered learning state
[  827.660025] bridge0: port 1(ens2.100) entered forwarding state
[  827.660772] bridge0: topology change detected, propagating
[  827.661520] IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready

# ls /sys/class/net/bridge0/brif
ens2.100

# nmcli con delete "bridge0 slave 1"
Connection 'bridge0 slave 1' (db232faa-7741-42af-a047-2b16fd91a44e) successfully deleted.