Difference between revisions of "Neutron/LBaaS/HowToRun"

Revision as of 22:59, 18 September 2015

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 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 the neutron-lbaas-agent and haproxy:

sudo apt-get install neutron-lbaas-agent haproxy

Once packages are installed make the directory for the LBaaS service and copy the configuration into place:

sudo mkdir -p /etc/neutron/plugins/services/agent_loadbalancer/
sudo cp /etc/neutron/lbaas_agent.ini /etc/neutron/plugins/services/agent_loadbalancer/lbaas_agent.ini

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.LoadBalancerPlugin/g" /etc/neutron/neutron.conf

/etc/openstack-dashboard/local_settings.py

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 <image-uuid> --flavor 1 server1
nova boot --image <image-uuid> --flavor 1 server2
nova boot --image <image-uuid> --flavor 1 client

Get the UUID of the private subnet.

neutron subnet-list

Created 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 <server1-ip> --protocol-port 80 pool1
neutron lbaas-member-create  --subnet private-subnet --address <server2-ip> --protocol-port 80 pool1

Create a Healthmonitor and associated 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\n\r\n<servername>' | sudo nc -l -p 80 ; done 

replacing <servername> 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://<server1-ip> 
wget -O - http://<server2-ip> 

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://<vip-ip> 
wget -O - http://<vip-ip> 
wget -O - http://<vip-ip> 
wget -O - http://<vip-ip> 

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 <vip-ip> 

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-<pool_id>, 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!)