network gateway parameters overwritten

[PaoloVIP]

proxmox-ve: 4.2-49 (running kernel: 4.4.8-1-pve)
pve-manager: 4.2-4 (running version: 4.2-4/2660193c)
pve-kernel-4.4.6-1-pve: 4.4.6-48
pve-kernel-4.2.6-1-pve: 4.2.6-36
pve-kernel-4.4.8-1-pve: 4.4.8-49
pve-kernel-4.2.8-1-pve: 4.2.8-41
pve-kernel-4.2.2-1-pve: 4.2.2-16
lvm2: 2.02.116-pve2
corosync-pve: 2.3.5-2
libqb0: 1.0-1
pve-cluster: 4.0-39
qemu-server: 4.0-74
pve-firmware: 1.1-8
libpve-common-perl: 4.0-60
libpve-access-control: 4.0-16
libpve-storage-perl: 4.0-50
pve-libspice-server1: 0.12.5-2
vncterm: 1.2-1
pve-qemu-kvm: 2.5-16
pve-container: 1.0-63
pve-firewall: 2.0-26
pve-ha-manager: 1.0-31
ksm-control-daemon: 1.2-1
glusterfs-client: 3.5.2-2+deb8u1
lxc-pve: 1.1.5-7
lxcfs: 2.0.0-pve2
cgmanager: 0.39-pve1
criu: 1.6.0-1
zfsutils: 0.6.5-pve9~jessie

With the latest update of proxmox (4.2-4) the custom gateway in /etc/network/interfaces will be overwritten from the web manager. For example look at the gateway:
( The network interfaces of a Debian 8 Lxc is configured in web manager with two bridge, two ip and no gateway at all.
net1->eth1->vmbr1->xxx.zz.y.4 no gateway
net2->eth2->vmbr2->192.168.0.5 no gateway )

auto lo
iface lo inet loopback

auto eth1
iface eth1 inet static
   address xxx.zz.y.4
   netmask 255.255.255.248
   post-up ip route add xxx.zz.y.0/29 dev eth1 src xxx.zz.y.4 table public
   post-up ip route add default via xxx.zz.y.6 dev eth1 table public
   post-up ip rule add from xxx.zz.y.4/32 table public
   post-up ip rule add to xxx.zz.y.4/32 table public

iface eth1 inet6 auto

auto eth2
iface eth2 inet static
   address 192.168.0.5
   netmask 255.255.255.0
   post-up ip route add 192.168.0.0/24 dev eth2 src 192.168.0.5 table internal
   post-up ip route add default via 192.168.0.254 dev eth2 table internal
   post-up ip rule add from 192.168.0.5/32 table internal
   post-up ip rule add to 192.168.0.5/32 table internal

iface eth2 inet6 static

will become, after reboot of lxc:

auto lo
iface lo inet loopback

auto eth1
iface eth1 inet static
  address xxx.zz.y.4
  netmask 255.255.255.248
  post-up ip route add xxx.zz.y.0/29 dev eth1 src xxx.zz.y.4 table public
  post-up ip rule add from xxx.zz.y.4/32 table public
  post-up ip rule add to xxx.zz.y.4/32 table public

iface eth1 inet6 auto

auto eth2
iface eth2 inet static
  address 192.168.0.5
  netmask 255.255.255.0
  post-up ip route add 192.168.0.0/24 dev eth2 src 192.168.0.5 table internal
  post-up ip rule add from 192.168.0.5/32 table internal
  post-up ip rule add to 192.168.0.5/32 table internal

iface eth2 inet6 auto

Maybe it is a design choice, but sometime it can be useful setting two gateway.

 

[wbumiller]

We're working on fixing this. In the mean time, there's now also a way to prevent PVE from touching the file.
So as a temporary workaround you can do this In the guest:

# touch /etc/network/.pve-ignore.interfaces

And remove it again once this behavior is fixed.

 

[PaoloVIP]

Thank you for your prompt replay. And, mostly, for your incredible, fantastic work.