OpenStack with Minimal Hardwares : All-In-One node Installation using Single NIC

Step 1:

You need to add an OpenVSwitch bridge for linking VM’s, assigning individual IP’s and exposing the VMs for external world to connect.Use the below command to add OpenVSwitch:

$ sudo ovs-vsctl add-br br-ex

Step 2:

Now configure the network at OS level.

The following is an example of how you can configure the network using /etc/network/interfaces:

auto lo

auto eth1 iface eth1 inet manual
up ip address add 0/0 dev $IFACE
up ip link set $IFACE up
up ifconfig $IFACE promisc
up ifconfig $IFACE multicast
down ip link set $IFACE down

auto br-ex iface br-ex inet static
address <static-ip-address>
netmask <mask>
network <network>
broadcast <broadcast>
gateway <gateway-ip-address>
up ifconfig $IFACE promisc
dns-nameservers <dns-ip-address>

a) The first entry configures the loopback interface: no explanation is needed.

b) The second entry “starts” the interface whenever you switch on the PC. It’s worth noticing that you do not assign any IP address to such an interface and this is needed because this interface will ‘capture’ all the traffic on the physical network it is connected to. The ‘captured’ traffic will be forwarded to all the virtual devices connected to the interfaces and one of such devices is br-ex.

c) The third entry configures br-ex, an OpenVSwitch bridge that will serve for the following purposes:

• give access to the services (API endpoints) and Horizon
• give access to the PC’s Operating System (ubuntu)
• give access to VMs in the cloud when they are associated to a floating IP address

After setting up the configuration file, all you need is to reboot the PC and not just network restart as sometimes the configuration files doesn’t get updated in the kernel. Once the reboot is completed, you need to access the console locally rather than remotely. As there is no IP address assigned yet.

After accessing through the local console, you should see that you have three interfaces (ifconfig command):

Lo Link encap:Local Loopbackinet addr:127.0.0.1 Mask:255.0.0.0inet6 addr: ::1/128 Scope:HostUP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:91931 errors:0 dropped:0 overruns:0 frame:0
TX packets:91931 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:19815734 (19.8 MB) TX bytes:19815734 (19.8 MB)

br-ex Link encap:Ethernet HWaddr 00:1a:4b:dd:44:5e
inet addr:10.15.5.92 Bcast:10.15.5.255 Mask:255.255.255.0
inet6 addr: fe80::9051:56ff:fe8d:568d/64 Scope:Link
UP BROADCAST RUNNING PROMISC MTU:1500 Metric:1
RX packets:3238 errors:0 dropped:8 overruns:0 frame:0
TX packets:415 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:383674 (383.6 KB) TX bytes:56880 (56.8 KB).

Note: You are still not in a position to connect via remotely. Please execute the below command to assign an IP address to enable remote connectivity and internet connection.

$ sudo ovs-vsctl add-port br-ex eth1

At this point you should be able to access the PC from “outside” using the IP address assigned to br-

Now you can start installing the OpenStack (omitting network configuration part) following the doc from docs.openstack.org

When you install Neutron, you need to ensure the floating IP address assigned should be in the same subnet.

Refer example give below

• when you create the “external network”, the floating IP addresses need to be on the same network where br-ex is (e.g. if the node is on 10.15.5.0/24, the floating IP address need to be on 10.15.5.0/24 as well).

Note : You cannot proceed with remote OpenStack installation while using one NIC.

Hope this is was useful. Would be interested to hear your inputs/feedback.

Cheers,
Vinoth