# ------------------------------------------
# Moving LXC containers between host systems
# ------------------------------------------

lxc_name=d.mx.oopen.de

lxc_base_dir_old_system="/data/lxc"
lxc_base_dir_new_system="/data/lxc"

new_host_system="o35.oopen.de"

# ---
# old host system
# ---

# Shutdown the container on old system
#
lxc-stop -n $lxc_name


# Archive container (rootfs & config)
#
# Note!:
# The --numeric-owner flag is very important! Without it, the container may not 
# boot because the uid/gids get mangled in the extracted filesystem. 
#
# When tar creates an archive, it preserves user / group ownership information. 
# By default, when extracting, tar tries to resolve the archive user/group ownership 
# names with the ids on the system running tar. This is intended to ensure that user 
# ownership is resolved on the new system, in case the UID numeric values differ b
# etween systems.
#
# This is bad for an LXC filesystem because the numeric uid/gid ownership is intended 
# to be preserved for the whole filesystem. If it gets resolved to a different value, 
# bad things happen.
#
cd "$lxc_base_dir_old_system"
tar --numeric-owner -czvf $lxc_name_fs.tar.gz $lxc_name


# Copy the created archive to your new server
#
rsync -avh $lxc_name_fs.tar.gz ${new_host_system}:${lxc_base_dir_new_system}/


# ---
# new host system
# ---

# Extract rootfs (including the lxc config  file)
#
cd "${lxc_base_dir_new_system}"
gunzip < $lxc_name_fs.tar.gz | tar --numeric-owner -xvf -


# ---
# Replace old ip-addresses with the new one
# ---

old_ipv4="83.223.86.92"
new_ipv4="95.217.204.227"
old_ipv6="2a01:30:0:13:254:9eff:fed5:e7fd"
new_ipv6="2a01:4f9:4a:47e5::227"

replace_base_dir="/data/lxc/d.mx/rootfs"

replace_ip_files="
   ${replace_base_dir}//etc/amavis/conf.d/50-user
   ${replace_base_dir}//etc/ipt-firewall/interfaces_ipv4.conf
   ${replace_base_dir}//etc/munin/munin-node.conf
   ${replace_base_dir}//etc/postfix/main.cf
   ${replace_base_dir}//etc/postfix/master.cf
   ${replace_base_dir}//etc/spamassassin/local.cf
   ${replace_base_dir}//usr/local/apache2/conf/extra/httpd-info.conf
   ${replace_base_dir}//usr/local/apache2/conf/vhosts/*.conf
"

for _file in $replace_ip_files ; do
   if [[ -f "$_file" ]]; then
      perl -i -n -p -e "s/${old_ipv4}/${new_ipv4}/g" $_file
      perl -i -n -p -e "s/${old_ipv6}/${new_ipv6}/g" $_file
   fi 
done