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Getting started with Load Balancer on Public Cloud

Stephanie R.
Updated

Learn how to configure an OVHcloud Load Balancer.

Our Public Cloud Load Balancer is based on OpenStack Octavia and is fully integrated into the Public Cloud universe.

 

Requirements

 

Instructions

OVHcloud Control Panel Access

 

Creating the Load Balancer

Click Load Balancer (under Network) in the left menu, then click the Create a Load Balancer button.

The configuration page will open.

Step 1: Region choice

  1. Select the zone type: 1AZ, Deployment in a single availability zone.
  2. Choose the region: Only regions where you have a private network and at least one subnet can be selected. Select the region and click Next.

Step 2: Size choice

The interface contains a link to the website on which the characteristics / benchmark of all size are provided. Once you have chosen your size, click Next.

Step 3: Attach a public IP (or not)

At this stage, you need to know if your Load Balancer will be receiving public traffic or not (for more details, read our Public Cloud Networking concepts page).

If your Load Balancer is processing public traffic, you have two options:

  • New Public IP: This option will create a new Floating IP for your Load Balancer.
  • If you already have a Floating IP, the interface will offer you to pick one.

If your Load Balancer is processing private traffic, choose No Public IP.

Step 4: Select the private network and the subnet where the Load Balancer will be spawned

The interface will inform you if the private network / subnet is not compliant with the prerequisites (see Public Cloud Networking concepts).

Step 5 (optional): Define the listener(s) and the members

  • First, choose the listener protocol & the port according to the traffic you will receive. Note that a specific listener called Prometheus is available to monitor your Load Balancer. In that case, it is not possible to add members. For more information on this listener, read the Monitor your Public Cloud Load Balancer with Prometheus guide.
  • Then, choose the Health Monitor type. Note that since some health monitor types are not compatible with some protocols, the user interface filters those types so that you can only choose compatible items. For more information on the health monitor compatibility, read the Public Cloud Networking concepts guide.
  • Finally, from the instances of your region, choose the member IP & port that will be part of the pool. Note that in order to simplify the configuration workflow, it is only possible to have a pool with the same protocol as the listener, and that the member can only be chosen from the instance. Those limitations can be bypassed by skipping this part of configuration and use the pool / member configuration once the Load Balancer is created.

PCLB_order_addInstances.png

In order to simplify the Load Balancer configuration workflow, it is only possible to have a pool with the same protocol as the listener and the member can only be chosen from the instance. Furthermore the pool load balancing algorithm is by default set to ROUND_ROBIN.

Those limitations can be bypassed by skipping this part of configuration and use the pool / member configuration once the Load Balancer is created.

Step 6: Define the name of Load Balancer

You can update the name according to your choice and click on Create a Load Balancer.

You will be redirected to the Load Balancer listing page. Among the attributes that are displayed, the Operating status and Provisioning status provide information on the state of your load balancer. Find more information on the "Load Balancer concepts" page.

Another way to create a Load Balancer is through the OpenStack Command Line Interface. Before you begin, consult the following guides:

Configuring your private network

Before creating a Load Balancer, you will need to set up a private network:

openstack network create my_network
 
openstack subnet create my_subnet --subnet-range <my_private_ip_range/mask> --network my_network --no-dhcp
 
openstack router create my_router
 
openstack router add subnet my_router my_subnet
 
openstack router set --external-gateway Ext-Net my_router

You can now attach your instances to the new network. We recommend following our guide to integrate an instance into vRack.

List the addresses of your instances in your network with the following command:

openstack server list

In the next step, configure the network interfaces of your instances according to this output.

Creating the Load Balancer

You can view a list of the different Load Balancer flavors we offer with this command:

openstack loadbalancer flavor list

You can now create your Load Balancer with the following command. In this example, we will create a "Small" Load Balancer.

openstack loadbalancer create --name my_load_balancer --flavor small --vip-subnet-id my_subnet

Your Load Balancer will be configured with an IP address of the private network. If you want to have access from the internet, you will need to attach a Floating IP address.

Attaching a Floating IP address to a Load Balancer

This is how to attach a Floating IP address to a Load Balancer:

openstack floating ip create Ext-Net
openstack floating ip set --port <my_load_balancer_vip_port_id> <floating_ip>

To retrieve the VIP port ID of your Load Balancer, use openstack loadbalancer show my_load_balancer.

Configuring your Load Balancer

In this example we will configure an HTTP Load Balancer. In order to listen on port 80 of the Load Balancer, create a Listener with this command:

openstack loadbalancer listener create --name my_listener_http --protocol HTTP --protocol-port 80 my_loadbalancer

Once the Listener has been created, you need to add each instance that can respond to external requests. To do this, you must create an Instance Pool:

openstack loadbalancer pool create --name my_pool_http --lb-algorithm ROUND_ROBIN --listener my_listener --protocol HTTP

Add your instances to the Instance Pool:

openstack loadbalancer member create --subnet-id my_subnet --address <private_ip_instance_1> --protocol-port 80 my_pool
openstack loadbalancer member create --subnet-id my_subnet --address <private_ip_instance_2> --protocol-port 80 my_pool

You can now access your Load Balancer via the Floating IP or private IP address from an instance in your private network.

Use the OVHcloud API to create a Load Balancer programmatically.

Retrieve available flavors

GET /cloud/project/{serviceName}/region/{regionName}/loadbalancing/flavor

Create the Load Balancer

POST /cloud/project/{serviceName}/region/{regionName}/loadbalancing/loadbalancer
{
  "flavorId": "<flavor_id>",
  "name": "my-load-balancer",
  "network": {
    "private": {
      "network": {
        "id": "<network_id>",
        "subnetId": "<subnet_id>"
      }
    }
  }
}

Attach a Floating IP (for public traffic)

POST /cloud/project/{serviceName}/region/{regionName}/loadbalancing/loadbalancer/{loadBalancerId}/floatingIp

Create a listener

POST /cloud/project/{serviceName}/region/{regionName}/loadbalancing/listener
{
  "loadbalancerId": "<loadbalancer_id>",
  "name": "my-listener",
  "port": 80,
  "protocol": "http"
}

Create a pool

POST /cloud/project/{serviceName}/region/{regionName}/loadbalancing/pool
{
  "algorithm": "roundRobin",
  "listenerId": "<listener_id>",
  "loadbalancerId": "<loadbalancer_id>",
  "name": "my-pool",
  "protocol": "http"
}

Add members to the pool

POST /cloud/project/{serviceName}/region/{regionName}/loadbalancing/pool/{poolId}/member
{
  "members": [
    { "address": "<private_ip_1>", "name": "member-1", "protocolPort": 80 },
    { "address": "<private_ip_2>", "name": "member-2", "protocolPort": 80 }
  ]
}

Use the OVHcloud CLI to manage your Load Balancer. Set your cloud project with --cloud-project <project_id> or configure it in your profile.

Create the Load Balancer

ovhcloud cloud loadbalancer create <region> \
  --name my-load-balancer \
  --size small \
  --network-id <network_id> \
  --subnet-id <subnet_id>

Attach a Floating IP (for public traffic)

ovhcloud cloud loadbalancer create-floating-ip <loadbalancer_id>

Create a listener

ovhcloud cloud loadbalancer listener create <region> \
  --loadbalancer-id <loadbalancer_id> \
  --name my-listener \
  --port 80 \
  --protocol http

Create a pool

ovhcloud cloud loadbalancer pool create <region> \
  --loadbalancer-id <loadbalancer_id> \
  --listener-id <listener_id> \
  --name my-pool \
  --algorithm roundRobin \
  --protocol http

Add members to the pool

ovhcloud cloud loadbalancer pool member create <pool_id> \
  --address <private_ip_1> --name member-1 --protocol-port 80
ovhcloud cloud loadbalancer pool member create <pool_id> \
  --address <private_ip_2> --name member-2 --protocol-port 80

Use the OVHcloud Terraform provider to create a Load Balancer with the ovh_cloud_project_loadbalancer resource.

Retrieve available flavors

data "ovh_cloud_project_loadbalancer_flavors" "flavors" {
  service_name = var.service_name
  region_name  = var.region
}

Create the Load Balancer

resource "ovh_cloud_project_loadbalancer" "lb" {
  service_name = var.service_name
  region_name  = var.region
  flavor_id    = data.ovh_cloud_project_loadbalancer_flavors.flavors.flavors[0].id
  name         = "my-load-balancer"
  network = {
    private = {
      network = {
        id        = var.network_id
        subnet_id = var.subnet_id
      }
    }
  }
}

 

Go further

Official documentation of OpenStack Octavia

Cookbook OpenStack Octavia

For more information and tutorials, please see our other Public Cloud support guides or explore the guides for other OVHcloud products and services.

If you need training or technical assistance to implement our solutions, contact your sales representative or click on this link to get a quote and ask our Professional Services experts for a custom analysis of your project.

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