Snippets hookscript can not change CT net config

[vaka]

Hi all,

I have a two node cluster PVE 7.3-4 on different data centers with different public networks.

LXC container running on node1 and replicated to node2.

I need to change container's network settings (MAC addres, ip-addres and gw) when it migrated on node2 and change it back when it migrated back on node1.
So I created hook-scripts at snippets on both nodes that change container's network settings on pre-start phase.

Script:

#!/bin/bash

ID=$1
PHASE=$2

echo "CT HOOK: $ID, PHASE: $PHASE"

case $PHASE in
  pre-start)
    if [[ "x$ID" == "x105" ]]; then
      echo pct set $ID -net0 name=eth0,bridge=vmbr0,firewall=0,gw=1.2.3.1,hwaddr=00:00:00:01:02:03,ip=1.2.3.115/24
      sudo /usr/sbin/pct set $ID -net0 name=eth0,bridge=vmbr0,firewall=0,gw=1.2.3.1,hwaddr=00:00:00:01:02:03,ip=1.2.3.115/24
    fi
    ;;
  *)
    exit 0
    ;;
esac

User "www-data" can sudo /usr/sbin/pct set *
Script works well when I run it by hand from user "www-data" but throw an error when it called by proxmox.

Output:

GUEST HOOK: 105, PHASE: pre-start
pct set 105 -net0 name=eth0,bridge=vmbr1,firewall=0,gw=1.2.3.1,hwaddr=00:00:00:01:02:03,ip=1.2.3.115/24
trying to acquire lock...
can't lock file '/run/lock/lxc/pve-config-105.lock' - got timeout
TASK ERROR: hookscript error for 105 on pre-start: command '/var/lib/vz/snippets/pct105-net0 105 pre-start' failed: exit code 4

Have somebody any idea how to automate changing network settings on container start?

 

[fabian]

the pre-start hook is called in a locked context, so it cannot do actions that in turn require obtaining the lock..

 

[vaka]

post-start hook also called in a locked context

So there is no way to automate lxc net config changing.

 

[vaka]

Finally I done it in a hack way. But it works.
I used "post-start" phase and simply change /etc/network/interfaces inside container.

#!/bin/bash

ID=$1
PHASE=$2
IMAGE="/rpool/subvol-${ID}-disk-0"

echo "GUEST HOOK: $ID, PHASE: $PHASE"

case $PHASE in
  post-start)
    if [[ "x$ID" == "x105" ]]; then
    cat <<EOF > $IMAGE/etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
        address 1.2.3.105/24
        gateway 1.2.3.1
        hwaddress ether 00:01:02:03:04:05
EOF
    fi
    ;;
  *)
    exit 0
    ;;
esac

 

[Mirmanium]

the pre-start hook is called in a locked context, so it cannot do actions that in turn require obtaining the lock..

Do we have any "alternative" to this behaviour? a simple "remove a passthrough drive if not connected" can not be done using hookscripts at start time

 

[Mirmanium]

Do we have any "alternative" to this behaviour? a simple "remove a passthrough drive if not connected" can not be done using hookscripts at start time

Ok, found a way. I know needs to be done carefully but if you put a
nohup ./script.sh > /dev/null 2>&1 &

code inside script.sh does not have locked context and just gets executed.

Thank you,