Neutron/LBaaS/HowToRun

Getting the Code
LBaaS introduces changes in the following modules: (currently all changes are in master branch)


 * neutron
 * python-neutronclient
 * horizon
 * devstack

Devstack Setup
Add the following lines to your localrc: enable_plugin neutron-lbaas https://github.com/openstack/neutron-lbaas.git enable_plugin octavia https://github.com/openstack/octavia.git ENABLED_SERVICES+=,q-lbaasv2 ENABLED_SERVICES+=,octavia,o-cw,o-hk,o-hm,o-api

Then run stack.sh

After stack.sh completes you'll be able to manage your Load Balancer via the CLI tools and within Horizon

Ubuntu Packages Setup
Install octavia with your favorite distribution:

pip install octavia

And edit the service_plugins in [DEFAULT] section in neutron.conf to enable the service: sudo sed -i.bak "s/\#\ service_plugins\ \=/service_plugins = neutron.plugins.services.agent_loadbalancer.plugin.LoadBalancerPluginv2/g" /etc/neutron/neutron.conf

Finally enable the Load Balancer section in Horizon by editing /etc/openstack-dashboard/local_settings.py and changing:

OPENSTACK_NEUTRON_NETWORK = { 'enable_lb': False }

to

OPENSTACK_NEUTRON_NETWORK = { 'enable_lb': True }

Once done restart your Neutron services and Apache to start using.

Topology Setup
Spin up three VMs, two to be servers, and one to be a client.

nova boot --image  --flavor 1 server1 nova boot --image  --flavor 1 server2 nova boot --image  --flavor 1 client

Get the UUID of the private subnet.

neutron subnet-list

Create a Loadbalancer:

neutron lbaas-loadbalancer-create --name lb1 private-subnet

Create a Listener:

neutron lbaas-listener-create --loadbalancer lb1 --protocol HTTP --protocol-port 80 --name listener1

Create a Pool:

neutron lbaas-pool-create --lb-algorithm ROUND_ROBIN --listener listener1 --protocol HTTP --name pool1

Create Members (using the IPs of server1 and server2): neutron lbaas-member-create --subnet private-subnet --address  --protocol-port 80 pool1 neutron lbaas-member-create --subnet private-subnet --address  --protocol-port 80 pool1

Create a Healthmonitor and associate it with the pool:

neutron lbaas-healthmonitor-create --delay 3 --type HTTP --max-retries 3 --timeout 3 --pool pool1

note the address for use below.

Validation
We now have two hosts with a load balancer pointed at them, but those hosts are not serving up any HTTP content.

A simple trick is to use netcat on the hosts to implement a simple webserver. For example, run:

while true; do echo -e 'HTTP/1.0 200 OK\r\nContent-Length: 8\r\n\r\n ' | sudo nc -l -p 80 ; done

replacing with "server1" and "server2" as appropriate. Once the server is started, you'll see incoming HTTP GET requests.. that's the load balancer health check in action!

If you have python installed, you can also create an index.html with the text "server1" or "server2" then in the same directory run

sudo python -m SimpleHTTPServer 80

Finally, to test real load balancing, from your client, use wget to make sure your requests are load-balanced across server1 and server2 as expected.

wget -O - http:// wget -O - http://

Then use wget to hit the load balancer IP(VIP IP) several times in succession. You should bounce between seeing server1 and server2.

wget -O - http:// wget -O - http:// wget -O - http:// wget -O - http://

If you get some trouble to curl vip-ip, can try the following method: sudo ip netns list qdhcp-xxx qrouter-xxx sudo ip netns exec qrouter-xxx curl -v 

Full list of LBaaS CLI commands is available at Quantum/LBaaS/CLI

Troubleshooting
LBaas is implemented similar to L3 + DHCP using namespaces. You can use "ip netns list" to find the namespace named qlbaas-, and then test connectivity from that namespace.

Use "screen -x stack" to view the q-svc ,q-lbaas, o-cw, o-api tabs for errors.

Grep syslog for "Octavia" to see messages from Octavia (though they are quite cryptic!)