iSCSI root with multiple NICs fails ifdown -a

[Malcolm Weir]

Ubuntu 14.04.4 LTS
ifupdown version 0.7.47.2ubuntu4.4

In /etc/init/networking.conf, there is a test for an iSCSI filesystem mounted by the initramfs, which tests to see if the file /etc/iscsi/iscsi.initramfs exists. If that file exists, the script exits immediately, which means that the event "deconfiguring-networking" never occurs.

The correct behavior would seem to be to detect which interface is being used for the iSCSI mount, and exclude just that interface from the "ifdown" command just after the event emission.

I.e. if the iSCSI volume is using eth2, then the ifdown command should be called as "ifdown -a --exclude=lo0 --exclude=eth2"

Appropriate code might be:

<BEGIN /etc/init/networking.conf>
# networking - configure virtual network devices
#
# This task causes virtual network devices that do not have an associated
# kernel object to be started on boot.

description "configure virtual network devices"

emits static-network-up
emits net-device-up
emits deconfiguring-networking

start on (local-filesystems
    and (stopped udevtrigger or container)) or runlevel [2345] or stopped networking RESULT=failed PROCESS=post-stop EXIT_STATUS=100
stop on unmounted-remote-filesystems

pre-start script
    if [ "$UPSTART_EVENTS" = "stopped" ] && [ "$UPSTART_JOB" = "networking" ] && [ "$EXIT_STATUS" = "100" ]; then
        exit 0
    fi

    mkdir -p /run/network
    ifup -a
end script

post-stop script
    if [ -z "$UPSTART_STOP_EVENTS" ]; then
        echo "Stopping or restarting the networking job is not supported."
        echo "Use ifdown & ifup to reconfigure desired interface."
        exit 100
    fi

    log_warning_msg() {
        echo $*
    }

    # These checks were taken from the Debian ifupdown.networking.init script
    check_network_file_systems() {
        [ -e /proc/mounts ] || return 0

        if [ -e /etc/iscsi/iscsi.initramfs ]; then
            if [ -e /dev/.initramfs/open-iscsi.interface ]
            then
                EXCL_NIC=`cat /dev/.initramfs/open-iscsi.interface`
                log_warning_msg "not deconfiguring specific network interface ${EXCL_NIC}: iSCSI root is mounted."
                EXCLUDE=" --exclude=${EXCL_NIC}"
            else
                log_warning_msg "not deconfiguring network interfaces: iSCSI root is mounted."
            fi
            exit 0
        fi

        while read DEV MTPT FSTYPE REST; do
            case $DEV in
            /dev/nbd*|/dev/nd[a-z]*|/dev/etherd/e*)
                log_warning_msg "not deconfiguring network interfaces: network devices still mounted."
                exit 0
                ;;
            esac
            case $FSTYPE in
            nfs|nfs4|smbfs|ncp|ncpfs|cifs|coda|ocfs2|gfs|pvfs|pvfs2|fuse.httpfs|fuse.curlftpfs)
                log_warning_msg "not deconfiguring network interfaces: network file systems still mounted."
                exit 0
                ;;
            esac
        done < /proc/mounts
    }

    check_network_swap() {
        [ -e /proc/swaps ] || return 0

        while read DEV MTPT FSTYPE REST; do
            case $DEV in
            /dev/nbd*|/dev/nd[a-z]*|/dev/etherd/e*)
                log_warning_msg "not deconfiguring network interfaces: network swap still mounted."
                exit 0
                ;;
            esac
        done < /proc/swaps
    }
<END>
    check_network_file_systems
    check_network_swap

    # Anything that manages network interfaces *MUST* wait for this event
    initctl emit deconfiguring-networking
    ifdown -a --exclude=lo ${EXCLUDE}
end script