containers/netavark

macvlan network option metric doesn't change the metric with dhcp

Opened this issue · 1 comments

literatesnow commented

Hello

OS: Linux pi5 6.6.47-3-rpi containers/common#1 SMP PREEMPT Sat Aug 31 07:27:25 MDT 2024 aarch64 GNU/Linux
Podman version: 5.2.2-1
Netavark version: 1.12.2-1

Preamble from related issue containers/common#2051 is identical:

I have a container attached to multiple macvlan networks. As some of the networks block access to the internet, my container sometimes can't access the internet as all routes have a default metric of 100.

I can now create a network with the metric option, which is great! However, it doesn't seem to take effect inside the container.

Background: There's 3 network interfaces on the host, one physical end0 and two vlan end0.100, end0.200. The vlan interfaces have metrics and end0.200 doesn't have a default gateway. All interfaces use DHCP.

$ id
uid=0(root) gid=0(root) groups=0(root)
$ ip route
default via 192.168.1.1 dev end0 proto dhcp src 192.168.1.101
default via 172.21.100.1 dev end0.100 proto dhcp src 172.21.100.101 metric 768
192.168.1.0/24 dev end0 proto kernel scope link src 192.168.1.101
172.21.100.0/24 dev end0.100 proto kernel scope link src 172.21.100.101 metric 768
172.31.200.0/24 dev end0.200 proto kernel scope link src 172.31.200.101 metric 1024
[...]

Creating the network with 3 different metric options (podman network inspect shows metric under options):

$ podman network create --driver macvlan --interface-name=end0 --ipam-driver=dhcp \
  --opt=metric=50 foo1
foo1
$ podman network create --driver macvlan --interface-name=end0.100 --ipam-driver=dhcp \
  --opt=metric=150 foo2
foo2
$ podman network create --driver macvlan --interface-name=end0.200 --ipam-driver=dhcp \
  --opt=metric=250 foo3
foo3

Running a container attached to all 3 networks:

$ podman run -ti --rm \
  "--network=foo3:mac=ba:d6:d5:c7:e6:7b" \
  "--network=foo2:mac=a6:87:e2:04:61:97" \
  "--network=foo1:mac=42:d3:60:fd:a8:92" \
  --entrypoint /bin/sh \
  docker.io/busybox:latest

Inside the container the metric is still 100:

/ # ip route
default via 192.168.1.1 dev eth2  metric 100
default via 172.21.100.1 dev eth1  metric 100
192.168.1.0/24 dev eth2 scope link  src 192.168.1.209
172.21.100.0/24 dev eth1 scope link  src 172.21.100.201
172.31.200.0/24 dev eth0 scope link  src 172.31.200.203
/ #

I'm expecting 192.168.1.1's metric to be 50 (end0) and 172.21.100.1's metric to be 150 (end0.100).

For more information on package versions and podman info please see attached.

Thanks!

Luap99 commented

Yeah this seems to be causes by the dhcp server not getting the mtu, if you use the host-local ipam driver it should work so this seems to be netavark bug then. Sorry it seems I didn't test with the dhcp driver last time around.

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