Accessing openstack instances hosted in Cloud

Question

I'm newbie to OpenStack! I've installed Openstack in Ubuntu Server 18.04 LTS on Microsoft Azure virtual machine (for my learning purpose because I don't have the required resources like 16GB RAM and 4 CPUs). I'm able to access the Openstack Dashboard with the help of public ip address of that VM using the browser in my machine. I've assigned floating ip address to the instance (here it is 172.24.4.8). My instance specs are

This is my network topology and my azure virtual machine's network configurations

azure vm's private ip = 192.168.0.4 azure vm's public ip = 20.193.227.12

I can access the OpenStack Dashboard using azure vm's public ip address, But I'm unable to access the instance via SSH from my local machine and from that azure virtual machine too. Help me how to access them!

Edit your question and provide more information. How did you deploy the OpenStack cloud? From where do you try to SSH to the instances? If your SSH client runs outside of the Ubuntu server, how did you connect the OpenStack cloud's external network to the Azure network? — berndbausch
Yes, but I still don't know how your networking is set up. There are hundred ways of doing this. You need to explain how you created the openstack cloud, and what measures you took to connect the cloud's external network to the Azure network. By "my machine", do you mean the Azure VM or something else? — berndbausch

berndbausch berndbausch · Accepted Answer · 2021-02-03T14:17:49

From your network topology screenshot, I guess that you used Devstack to create the cloud. Can you confirm that?

The external network named public is not connected to the world outside the cloud in any way. This is so because by default, Devstack creates an isolated external network for testing purposes. You should be able to access the instance from the Azure VM, however. The information given is not sufficient to explain why you can't.

See the Devstack networking page. It states that the

br-ex interface (...) is not connected to any physical interfaces

This is the technical reason for not being able to access instances.

The Shared Guest Interface section of the above page documents how to connect a Devstack cloud to a real external network.

EDIT:

The Shared Guest Interface instructions ask you to set this:

PUBLIC_INTERFACE= NIC connected to external network. *eth0* in your case.
HOST_IP= *192.168.0.4* for you
FLOATING_RANGE= Your netmask is 255.255.255.128, which translates to a network prefix of 25, 
                I think. If I am right, the value is *192.168.0.0/25*.
PUBLIC_NETWORK_GATEWAY= The IP address of the router on the *192.168.0.0/25* network.
Q_FLOATING_ALLOCATION_POOL= The range of addresses from FLOATING_RANGE 
                            that you want to use as floating IPs for 
                            your OpenStack instances.

FLAT_INTERFACE might be an old setting for the defunct Nova-Network service. I don't see it mentioned at all in the Ussuri version of Devstack.

Accessing openstack instances hosted in Cloud

1 Answers