bridge-utils incompatible with ifupdown on bionic

Status changed to 'Confirmed' because the bug affects multiple users.

apt-cache show bridge-utils | grep -E "Pack|Vers|Confl"
Package: bridge-utils
Version: 1.5-15ubuntu1
Conflicts: ifupdown (<< 0.8.17)

So that conflict applies to ifupdown 0.8.16ubuntu2 in Bionic

thanks @albrt, I didn't know that one

That conflicts was updated in this Debian change:

diff --git a/debian/changelog b/debian/changelog
index 845b518..ecc3f29 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+bridge-utils (1.5-12) unstable; urgency=medium
+
+ * Add vlan support so that old setups using vlans as ports don't break.
+
+ -- Santiago Garcia Mantinan <email address hidden> Sun, 22 Jan 2017 00:23:50 +0100
+
 bridge-utils (1.5-11) unstable; urgency=low

   * Change /etc/default/bridge-utils to enable addition of hotplugged
diff --git a/debian/control b/debian/control
index c9b33ed..2b21fee 100644
--- a/debian/control
+++ b/debian/control
@@ -10,7 +10,7 @@ Architecture: linux-any
 Multi-Arch: foreign
 Depends: ${shlibs:Depends}, ${misc:Depends}
 Suggests: ifupdown
-Conflicts: ifupdown (<< 0.6.0)
+Conflicts: ifupdown (<< 0.8.17)
 Description: Utilities for configuring the Linux Ethernet bridge
  This package contains utilities for configuring the Linux Ethernet
  bridge in Linux. The Linux Ethernet bridge can be used for connecting
diff --git a/debian/ifupdown.sh b/debian/ifupdown.sh
index 95dac90..517f084 100644
--- a/debian/ifupdown.sh
+++ b/debian/ifupdown.sh
@@ -66,6 +66,7 @@ do
   do
     # We attach and configure each port of the bridge
     if [ "$MODE" = "start" ] && [ ! -d /sys/class/net/$IFACE/brif/$port ]; then
+ create_vlan_port
       if [ "$IF_BRIDGE_HW" ]
       then
         KVER="$(uname -r)"
@@ -84,7 +85,7 @@ do
       brctl addif $IFACE $port && ip link set dev $port up
     # We detach each port of the bridge
     elif [ "$MODE" = "stop" ] && [ -d /sys/class/net/$IFACE/brif/$port ]; then
- ip link set dev $port down && brctl delif $IFACE $port && \
+ ip link set dev $port down && brctl delif $IFACE $port && destroy_vlan_port
       if [ -f /proc/sys/net/ipv6/conf/$port/disable_ipv6 ]
       then
         echo 0 > /proc/sys/net/ipv6/conf/$port/disable_ipv6

Yes andreas, this is the issue I mentioned on IRC.
AFAIK I think foundations is on that.

I'm subscribing the few that I've seen mentioning it for awareness.
So that they can dup it if they have another bug for that already.

I was looking at the test fail in proposed migration.

I realized it fails on ppc64 since 14th August 2017 (and since then it always fails, confirmed by a retry and [1] - even in Artful it fails since then).

It unfortunately fails without any message.

I found in hints-ubuntu/vorlon
# regressed in release; maybe related to resolved/netplan.
force-badtest ifupdown/0.8.16ubuntu2/ppc64el

I tried to recreate that in a VM on ppc.
1. installing ifupdown gives a valid /e/n/i to run the test
2. Test exec reproduces the issue we see in CI
   Verbose log
+ IFACE=sdtest42
+ [ -e /sys/class/net/sdtest42 ]
+ grep -q source-directory .*interfaces.d /etc/network/interfaces
+ grep -q source .*interfaces.d.*cfg /etc/network/interfaces
+ IFACE_CFG=/etc/network/interfaces.d/sdtest42.cfg
+ cat
+ ip link add name sdtest42 type veth peer name vsdtest42
+ trap ip link del dev sdtest42; rm /etc/network/interfaces.d/sdtest42.cfg EXIT INT QUIT PIPE
+ sleep 3
+ ifquery --state sdtest42
+ ip link del dev sdtest42
+ rm /etc/network/interfaces.d/sdtest42.cfg

That means the ifquery fails, and the set -e triggers the trap
=> No message, buu RC=1

Comparing x86/ppc on this in detail
1. VM fresh from cloud image (20180321)
   => no /etc/network/interfaces

2. installed (current) ifupdown
   $ cat /etc/network/interfaces
   # interfaces(5) file used by ifup(8) and ifdown(8)
   # Include files from /etc/network/interfaces.d:
   source-directory /etc/network/interfaces.d

3. purged ifupdown
   leaves e/n/i

4. reinstall from proposed
   still the same e/n/i
=> Until here all is fine, and if installing ifupdown (on a fresh system) drops /e/n/i that explains why no test goes to the SKIP condition.

5. Set up prep steps as the test does
IFACE_CFG=/etc/network/interfaces.d/sdtest42.cfg
IFACE=sdtest42
cat <<EOF > $IFACE_CFG
allow-hotplug $IFACE
iface $IFACE inet static
    address 192.168.234.129
    netmask 255.255.255.0
EOF
=> check status (before adding dev via IP)
$ systemctl status -l <email address hidden>; ifquery -l --allow=hotplug; ifquery sdtest42;
● <email address hidden> - ifup for sdtest42
   Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled)
   Active: inactive (dead)
Unknown interface sdtest42
# The same on x86 and ppc64

6. add dev (comment says: these should trigger uevents and ifup@.service)
$ ip link add name $IFACE type veth peer name v$IFACE
Check status again shows it is still as dead as before.
# systemctl status -l <email address hidden>; ifquery -l --allow=hotplug; ifquery sdtest42;
● <email address hidden> - ifup for sdtest42
   Loaded: loaded (/lib/systemd/system/ifup@.service; static; vendor preset: enabled)
   Active: inactive (dead)
Unknown interface sdtest42

The device itself is there after the add
$ ll /sys/class/net/sdtest42
lrwxrwxrwx 1 root root 0 Mär 22 07:20 /sys/class/net/sdtest42 -> ../../devices/virtual/net/sdtest42/

ifquery does not find the device config (here as it should look like on xenial):
$ ifquery sdtest42
address: 192.168.234.129
netmask: 255.255.255.0
broadcast: 192.168.234.255

7. I tried to fix via enabling old style networking
$ systemctl disable systemd-networkd.socket
$ ...

This bug was fixed in the package ifupdown - 0.8.17ubuntu1

---------------
ifupdown (0.8.17ubuntu1) bionic; urgency=medium

  * Merge from Debian unstable.
    - Resolve conflicts with newer bridge-utils. LP: #1756846.
  * Remaining changes:
    - Always call dhclient with -1, Ubuntu carries a patch so that renewal
      won't time out.
    - ifup@.service, ifupdown-hotplug: Additionally run for "auto" class. We
      don't really support "allow-hotplug" in Ubuntu at the moment, so we need
      to deal with "auto" devices appearing after the "networking" init script
      already ran. (LP: #1374521)
    - Drop obsolete upstart integration.
  * Dropped changes, included in Debian:
    - networking.service: exclude loopback device lo in ExecStop.
    - Export $CLASS to scripts.
    - Add a few missing voids for functions that do not take any parameters.
    - Add a bug-script to automatically add /etc/network/interfaces etc. to
      reportbug output.
    - debian/ifup@.service: Start after device is up
  * Dropped changes, superseded in Debian:
    - disabled upping of bridges: this is now handled exclusively through
      ifupdown, bridge-utils hook no longer handles this at all.

ifupdown (0.8.17) unstable; urgency=medium

  [ Scott Moser ]
  * Don't bring down the loopback interface when networking.service stops.
    Closes: #841106, #841107

  [ Guus Sliepen ]
  * Export $CLASS to scripts.
  * Add a bug-script.
  * Depend on freebsd-net-tools instead of net-tools.
  * Also configure VLANs on bridge interfaces (see #818849).
  * Improve manpage: simplify example, add more section headers.
    Closes: #840579
  * Provide IPv6 examples in /u/s/d/ifupdown/examples/network-interfaces.
    Closes: #703568
  * Use -4 option for IPv4 dhclient. Closes: #844592

  [ Martin Pitt ]
  * ifup@.service: start After the corresponding
    sys-subsystem-net-devices device.

 -- Steve Langasek <email address hidden> Wed, 21 Mar 2018 14:53:25 -0700

I had to install ifupdown manually, and got 0.8.17ubuntu1. everything fine now, but shouldn't this package be pulled in automatically somehow?