This is pretty common. In my opinion the setup of the VNC console is pretty vague.

Please post your nova.conf from your controller and compute node.

After making any changes restart all of the nova services if you are unsure which one is needed.

Your compute should look like this:

vnc_enabled = True
vncserver_listen = 0.0.0.0
vncserver_proxyclient_address = LOCAL_MANAGEMENT_INTERFACE_IP_ADDRESS
novncproxy_base_url = http://controller:6080/vnc_auto.html

Your controller should look like this:

my_ip = LOCAL_MANAGEMENT_INTERFACE_IP_ADDRESS
vncserver_listen = LOCAL_MANAGEMENT_INTERFACE_IP_ADDRESS
vncserver_proxyclient_address = LOCAL_MANAGEMENT_INTERFACE_IP_ADDRESS

For more information look here

Just installing nova-consoleauth and nova-novncproxy would not solve the problem, you need to change your /etc/nova/nova.conf to access console. You have to set up novncproxy_base_url, vncserver_proxyclient_address and vncserver_listen variables in configuration file of controller. You can see an example of nova.conf file for controller at

   http://docs.openstack.org/juno/config-reference/content/section_compute-config-samples.html

for compute node use configuration options defined in the following guide

     http://docs.openstack.org/icehouse/install-guide/install/apt/content/nova-compute.html

Don't forget to change IP address defined in this document to your systems IP address.

Your novncproxy_base_url must be accessible to the system, you are using dashboard on because it is point where your dasboard will contact for the console. So, in case you are using dashboard on external world make sure this url must have public IP address. If you are using dashboard on the same machine or in the private network then it can have private IP address. If it does not solve the problem then please provide your /etc/nova/nova.conf and setup info(IP address and which node has what components).

If i understood correctly, you have installed controller node on the container inside the physical server. Because containers create their NAT at the host and you can not access containers inside a machine untill you have not mapped the port to the external machine. Map all the port to the physical machine and give the address of the external machine in the configuration of the compute node. If i have misunderstood, please provide more details regarding IP of the container of controller node. IP address of the external machine and compute node.

@Xeek Force to use the answer box for words limitation in comments.

if your configuration is managed by deployment tools like juju , chef etc. normally they will be overwritten if you change anything, there are two ways to make your change persistent:

1. modify the configuration script in juju or chef and rerun the configuration action 
2. after your made changes then use the linux command like this   chattr +i  /etc/nova/nova.conf to prevent the overwritten.

We have used the option2 in practice and it is a shortcut.

Hope that helps!

Vic