[Lxc-users] container hostname not visible to host, ubuntu 12.04

[ronkaluta]

I recently ran across a similar situation where I could not access the 
container behind a firewall.

This is how I got around that:

My host configuration:
##############################
xxxx at lxc3100:~# ifconfig
br0       Link encap:Ethernet  HWaddr 00:26:18:81:1e:7d
           inet addr:172.31.32.100  Bcast:172.31.255.255 Mask:255.255.0.0
           inet6 addr: fe80::226:18ff:fe81:1e7d/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:5957760 errors:0 dropped:0 overruns:0 frame:0
           TX packets:3716467 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:10228096239 (10.2 GB)  TX bytes:277123308 (277.1 MB)

br1       Link encap:Ethernet  HWaddr 00:0e:0c:85:da:85
           inet addr:192.168.2.100  Bcast:192.168.2.255 Mask:255.255.255.0
           inet6 addr: fe80::20e:cff:fe85:da85/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:26142 errors:0 dropped:0 overruns:0 frame:0
           TX packets:994 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:2353115 (2.3 MB)  TX bytes:85436 (85.4 KB)

eth0      Link encap:Ethernet  HWaddr 00:26:18:81:1e:7d
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:7079456 errors:0 dropped:0 overruns:0 frame:0
           TX packets:3899570 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:10396462129 (10.3 GB)  TX bytes:425272196 (425.2 MB)
           Interrupt:42 Base address:0x2000

eth1      Link encap:Ethernet  HWaddr 00:0e:0c:85:da:85
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:40970 errors:0 dropped:0 overruns:0 frame:0
           TX packets:4890 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:4198163 (4.1 MB)  TX bytes:409130 (409.1 KB)

lo        Link encap:Local Loopback
           inet addr:127.0.0.1  Mask:255.0.0.0
           inet6 addr: ::1/128 Scope:Host
           UP LOOPBACK RUNNING  MTU:16436  Metric:1
           RX packets:19 errors:0 dropped:0 overruns:0 frame:0
           TX packets:19 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:1572 (1.5 KB)  TX bytes:1572 (1.5 KB)

lxcbr0    Link encap:Ethernet  HWaddr 52:45:5f:77:8e:5c
           inet addr:10.0.3.1  Bcast:10.0.3.255  Mask:255.255.255.0
           inet6 addr: fe80::98a6:cbff:fef9:ced3/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:3643193 errors:0 dropped:0 overruns:0 frame:0
           TX packets:6874148 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:216300770 (216.3 MB)  TX bytes:10328729114 (10.3 GB)

##############################
My container configuration:

xxxx at ubumirror3101:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 62:c3:08:bc:de:7d
           inet addr:10.0.3.224  Bcast:10.0.3.255  Mask:255.255.255.0
           inet6 addr: fe80::60c3:8ff:febc:de7d/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:258 errors:0 dropped:0 overruns:0 frame:0
           TX packets:374 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:20981 (20.9 KB)  TX bytes:34366 (34.3 KB)

eth1      Link encap:Ethernet  HWaddr e6:f6:c5:e0:30:4d
           inet addr:172.31.30.101  Bcast:172.31.255.255 Mask:255.255.0.0
           inet6 addr: fe80::e4f6:c5ff:fee0:304d/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:1747 errors:0 dropped:0 overruns:0 frame:0
           TX packets:555 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:176521 (176.5 KB)  TX bytes:69446 (69.4 KB)

eth2      Link encap:Ethernet  HWaddr 46:59:45:fa:67:11
           inet addr:192.168.2.101  Bcast:192.168.2.255 Mask:255.255.255.0
           inet6 addr: fe80::4459:45ff:fefa:6711/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:1454 errors:0 dropped:0 overruns:0 frame:0
           TX packets:311 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:130089 (130.0 KB)  TX bytes:27156 (27.1 KB)

lo        Link encap:Local Loopback
           inet addr:127.0.0.1  Mask:255.0.0.0
           inet6 addr: ::1/128 Scope:Host
           UP LOOPBACK RUNNING  MTU:16436  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
##############################
A small bash shell script to create a new route and survive after reboots:

#!/bin/bash
# File: container_gateway-sh
#---------------------------------------
gateway_setup ()
{
if [[ ! -e  /etc/init.d/rkgateway ]]
then
cat <<EOF > /etc/init.d/rkgateway
         #!/bin/sh -e
         # File: /etc/init.d/rkgateway
         route add default gateway 192.168.2.1
         wait
         EOF
wait
chmod +x /etc/init.d/rkgateway; wait
update-rc.d rkgateway defaults 98 02; wait
fi
}
# to remove
# update-rc.d -f rkgateway remove
#
gateway_setup
##################################

Ron Kaluta