Openstack working from my instance: Connecting to nova.clouds.ubuntu Cannot initiate connection -

i new openstack, i've installed using devstack. launched instance using ubuntu server cloud image heat flavor. can ssh instance. problem when trying do:

sudo apt-get update  sudo apt-get install openjdk-7-jdk 

i have

0% (connecting nova.clouds.archive.ubuntu.com ip@)

it keeps changing ip@ error cannot initiate connection nova connect(101: network unreachable)

i associating floating ip instance

update

ubuntu@selftrusty:~$ ifconfig eth0      link encap:ethernet  hwaddr fa:16:3e:45:31:47             inet addr:10.0.0.2  bcast:10.0.0.255  mask:255.255.255.0           inet6 addr: fe80::f816:3eff:fe45:3147/64 scope:link           broadcast running multicast  mtu:1500  metric:1           rx packets:5358 errors:0 dropped:0 overruns:0 frame:0           tx packets:5994 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            rx bytes:383312 (383.3 kb)  tx bytes:979324 (979.3 kb)  lo        link encap:local loopback             inet addr:127.0.0.1  mask:255.0.0.0           inet6 addr: ::1/128 scope:host           loopback running  mtu:65536  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) 

i had sudo iptables -t nat -a postrouting -o eth0 -j masquerade in host