Load balance traffic by request URL

You can direct traffic to different target groups of servers depending on the domain and path specified in the request.

Control panel

1. In the control panel, on the top menu, click Products and select Cloud Servers.

2. Go to the Load Balancers section → Load Balancers tab.

3. Open the load balancer page.

4. Click Create Rule.

5. Select the traffic reception protocol — HTTPS. The standard port 443 will be automatically selected, on which the load balancer will listen for traffic.

6. Select a certificate to terminate HTTPS traffic on the load balancer — choose a certificate from the secret manager or upload a new one. If the rule is to receive traffic for multiple domains, the certificate must be valid for all domains, or add multiple certificates.

7. Select a default target group — traffic that does not fall under any HTTP policies will be directed there. Select a group from the list or create a new target group, specify the HTTP traffic destination protocol and port 80 for it. If you want to drop traffic that does not fall under an HTTP policy, select Without target group.

8. Select the HTTP request headers that will be passed to the servers.

9. Create an HTTP policy to use for traffic balancing. To do this, click Add new policy.

10. To balance a request by domain name, select the check condition: HOSTNAME — EQUAL TO.

11. Enter the domain name without the protocol, for example example.com.

12. Click New condition.

13. To balance a request by path, select the check condition: PATH — STARTS WITH.

14. Enter the text that the request path should start with, for example /api.

15. Select the Redirect to target group action.

16. Select the target group where traffic that matches the policy will be directed. To create a new target group, click New target group and create a target group with the HTTP protocol and port 80. If you want to drop traffic that does not fall under an HTTP policy, select Without target group.

17. Optional: change the policy name or leave the one generated by default.

18. Click Add.

19. Optional: open the Advanced rule settings block and specify the connection settings:

    • for incoming requests to the load balancer — specify the connection timeout and maximum number of connections;
    • for requests from the load balancer to servers — specify the connection timeout, inactivity timeout, and TCP packet wait timeout.

20. Click Create.

OpenStack CLI

1. Open the OpenStack CLI.

2. If you do not have a target group to balance traffic into yet, create one:

   openstack loadbalancer pool create \
     --name <pool_name> \
     --lb-algorithm <algorithm> \
     --loadbalancer <loadbalancer> \
     --protocol HTTP

   Specify:

   • <pool_name> — name of the target group;
   • <algorithm> — name of the algorithm: ROUND_ROBIN or LEAST_CONNECTIONS
   • <loadbalancer> — ID or name of the load balancer. You can view the list with the command openstack loadbalancer list.

3. If you created a target group in step 2, add a server to it:

   openstack loadbalancer member create \
     --subnet-id <subnet_uuid> \
     --address <server_ip_address> \
     --protocol-port 80 \
     <pool>

   Specify:

   • <subnet_uuid> — ID of the server's private or public subnet. You can view the list with the command openstack subnet list;
   • <server_ip_address> — private IP address of the server. You can copy it in the control panel: from the top menu, click Products → Cloud Servers → server page → tab Ports → in the port card, click next to the IP address;
   • <pool> — ID or name of the target group created in step 2.

4. Create a rule for the load balancer with the TERMINATED_HTTPS protocol and port 443:

   openstack loadbalancer listener create \
     --name <listener_name> \
     --protocol TERMINATED_HTTPS \
     --protocol-port 443 \
     --default-tls-container=<certificate_uuid> \
     --default-pool <default_pool> \
     <loadbalancer>

   Specify:

   • <listener_name> — rule name;
   • <certificate_uuid> — ID of the TLS(SSL) certificate for traffic termination on the load balancer. You can copy it in the control panel: from the top menu, click Products → Certificate Manager → in the menu of the certificate, select Copy UUID. If the rule is to receive traffic for multiple domains, the certificate must be valid for all domains, or add multiple certificates;
   • optional: --default-pool <default_pool> — ID or name of the default target group to which traffic not falling under any HTTP policies in the rule will be directed. You can view the list of groups with the openstack loadbalancer pool list command. If you do not have a suitable target group, create one. If you do not specify this parameter, traffic not falling under the policies will be dropped;
   • <loadbalancer> — ID or name of the load balancer. You can view the list with the command openstack loadbalancer list.

5. Create an HTTP policy in the rule:

   openstack loadbalancer l7policy create \
     --action REDIRECT_TO_POOL \
     --redirect-pool <pool> \
     --name <policy_name> \
     <listener_name>

   Specify:

   • <pool> — ID or name of the target group. You can view the list with the command openstack loadbalancer pool list;
   • <policy_name> — name of the L7 policy;
   • <listener_name> — name of the rule you set in step 4.

6. To balance a request by domain name, create a condition in the HTTP policy to check the domain:

   openstack loadbalancer l7rule create \
     --compare-type EQUAL_TO \
     --type HOST_NAME \
     --value <domain_name> \
     <policy>

   Specify:

   • <domain_name> — domain such as example.com;
   • <policy> — ID or name of the L7 policy. You can view the list with the command openstack loadbalancer l7policy list.

7. To balance a request by path, create a condition in the HTTP policy to check the path:

   openstack loadbalancer l7rule create \
     --compare-type STARTS_WITH \
     --type PATH \
     --value <path> \
     <policy>

   Specify:

   • <path> — text that the request path should start with, for example /api;
   • <policy> — ID or name of the L7 policy. You can view the list with the command openstack loadbalancer l7policy list.