In a recent post I discussed the OpenStack Octavia project which provides a backend to Neutron’s LBaaS system.
In this post I’ll just go over a quick example of creating and using a load balancer and using it in OpenStack.
The official docs are pretty good on this, but it’s worthwhile to cover them in a real environment.
I’ve already created two web servers, web-1 and web-2.
$ os server list | grep web-
| 05f0bb14-2895-4c7b-a493-ef2a1b57c721 | web-2 | ACTIVE | vxlan1=10.50.0.15 | xenial |
| 3ff621cd-46cb-4fcf-8d9d-2193718a11f5 | web-1 | ACTIVE | vxlan1=10.50.0.35 | xenial |
I’ve also changed each of the /var/www/html/index.html pages to have only the hostname in it, so that if you connect to port 80 on either of them they respond with their hostname.
First, we create a load balancer and put it onto a specific network.
$ neutron lbaas-loadbalancer-create --name web-lb vxlan1-subnet
Created a new loadbalancer:
+---------------------+--------------------------------------+
| Field | Value |
+---------------------+--------------------------------------+
| admin_state_up | True |
| description | |
| id | 6b9c75c1-4af2-424d-8b20-681926de4e0d |
| listeners | |
| name | web-lb |
| operating_status | OFFLINE |
| pools | |
| provider | octavia |
| provisioning_status | PENDING_CREATE |
| tenant_id | 3b29434130cd487186f1da0b5831232f |
| vip_address | 10.50.0.11 |
| vip_port_id | b88dd055-e963-4227-86e1-558df52dc946 |
| vip_subnet_id | 5ce133ce-cce6-4142-89d4-a71da87bbde6 |
+---------------------+--------------------------------------+
Show the newly created loadbalancer. Note the “octavia” provider, and the IP the load balancer received.
$ neutron lbaas-loadbalancer-show web-lb
+---------------------+--------------------------------------+
| Field | Value |
+---------------------+--------------------------------------+
| admin_state_up | True |
| description | |
| id | 6b9c75c1-4af2-424d-8b20-681926de4e0d |
| listeners | |
| name | web-lb |
| operating_status | ONLINE |
| pools | |
| provider | octavia |
| provisioning_status | ACTIVE |
| tenant_id | 3b29434130cd487186f1da0b5831232f |
| vip_address | 10.50.0.11 |
| vip_port_id | b88dd055-e963-4227-86e1-558df52dc946 |
| vip_subnet_id | 5ce133ce-cce6-4142-89d4-a71da87bbde6 |
+---------------------+--------------------------------------+
There is also an existing security group called web that allows port 80.
$ os security group list | grep web
| db3f7e2d-2453-416d-8651-ba8544502d0f | web | web | 3b29434130cd487186f1da0b5831232f |
The security group must be added to the LB VIP port which was shown above in the LB show.
$ neutron port-update --security-group web b88dd055-e963-4227-86e1-558df52dc946
Updated port: b88dd055-e963-4227-86e1-558df52dc946
Now to create a listener.
$ neutron lbaas-listener-create --name web-lb-http --loadbalancer web-lb --protocol HTTP --protocol-port 80
Created a new listener:
+---------------------------+------------------------------------------------+
| Field | Value |
+---------------------------+------------------------------------------------+
| admin_state_up | True |
| connection_limit | -1 |
| default_pool_id | |
| default_tls_container_ref | |
| description | |
| id | 364c08e7-29a6-4c02-b6e6-7b0d18f3e10e |
| loadbalancers | {"id": "6b9c75c1-4af2-424d-8b20-681926de4e0d"} |
| name | web-lb-http |
| protocol | HTTP |
| protocol_port | 80 |
| sni_container_refs | |
| tenant_id | 3b29434130cd487186f1da0b5831232f |
+---------------------------+------------------------------------------------+
Create a pool.
$ neutron lbaas-pool-create \
> --name web-lb-pool-http \
> --lb-algorithm ROUND_ROBIN \
> --listener web-lb-http \
> --protocol HTTP
Created a new pool:
+---------------------+------------------------------------------------+
| Field | Value |
+---------------------+------------------------------------------------+
| admin_state_up | True |
| description | |
| healthmonitor_id | |
| id | 19e86ff3-aa58-4582-8399-4ad3c9eaeb9d |
| lb_algorithm | ROUND_ROBIN |
| listeners | {"id": "364c08e7-29a6-4c02-b6e6-7b0d18f3e10e"} |
| loadbalancers | {"id": "6b9c75c1-4af2-424d-8b20-681926de4e0d"} |
| members | |
| name | web-lb-pool-http |
| protocol | HTTP |
| session_persistence | |
| tenant_id | 3b29434130cd487186f1da0b5831232f |
+---------------------+------------------------------------------------+
Add the first member.
$ neutron lbaas-member-create \
> --subnet vxlan1-subnet \
> --address 10.50.0.35 \
> --protocol-port 80 \
> web-lb-pool-http
Created a new member:
+----------------+--------------------------------------+
| Field | Value |
+----------------+--------------------------------------+
| address | 10.50.0.35 |
| admin_state_up | True |
| id | 38fb7a37-24f4-4fc5-a50b-4e21502d239e |
| name | |
| protocol_port | 80 |
| subnet_id | 5ce133ce-cce6-4142-89d4-a71da87bbde6 |
| tenant_id | 3b29434130cd487186f1da0b5831232f |
| weight | 1 |
+----------------+--------------------------------------+
Add the second member.
$ neutron lbaas-member-create \
> --subnet vxlan1-subnet \
> --address 10.50.0.15 \
> --protocol-port 80 \
> web-lb-pool-http
Created a new member:
+----------------+--------------------------------------+
| Field | Value |
+----------------+--------------------------------------+
| address | 10.50.0.15 |
| admin_state_up | True |
| id | 02074bde-90b2-4c0d-bfb1-2bb2e215d7fb |
| name | |
| protocol_port | 80 |
| subnet_id | 5ce133ce-cce6-4142-89d4-a71da87bbde6 |
| tenant_id | 3b29434130cd487186f1da0b5831232f |
| weight | 1 |
+----------------+--------------------------------------+
A floating IP has already been created.
$ neutron floatingip-list
+--------------------------------------+------------------+---------------------+---------+
| id | fixed_ip_address | floating_ip_address | port_id |
+--------------------------------------+------------------+---------------------+---------+
| 9e048a99-8533-4dc6-9e6f-1347c09d28e9 | | <floating ip> | |
+--------------------------------------+------------------+---------------------+---------+
Actually associate the floating IP. In this case we are associating a floating IP with a port instead of a “server.”
neutron floatingip-associate 9e048a99-8533-4dc6-9e6f-1347c09d28e9 b88dd055-e963-4227-86e1-558df52dc946
Associated floating IP 9e048a99-8533-4dc6-9e6f-1347c09d28e9
Now that the floating IP is up and attached to a working load balancer, and behind it is a couple of working web servers…
$ while true; do curl <floating ip>; sleep 1; done
web-2
web-1
web-2
web-1
web-2
web-1
web-2
web-1
^