Configure load balancer in a Managed Kubernetes cluster for Ingress

warning

Once a Managed Kubernetes cluster has been created, we recommend that all balancer actions be performed only via kubectl. Changes made in any other way are not saved in Kubernetes manifests. When recreating the cluster, balancer or synchronizing manifests, such changes will be undone.

The load balancer in Managed Kubernetes is used to distribute incoming traffic between pods.

If you are using Ingress Controller Traefik, the load balancer will be automatically created when you install Ingress Controller Traefik. To configure the load balancer during installation, use the Install Ingress Controller Traefik instructions. All annotations for configuring the load balancer that are described in these instructions apply to Ingress Controller Traefik only through the values.yaml file.

If you are using a different Ingress Controller without automatically creating a load balancer or the additional load balancer is needed for other applications, create a load balancer.

Create a load balancer

Connect to the cluster](/managed-kubernetes/clusters/connect-to-cluster.mdx).
Create a yaml file with a manifest for a Service object of type LoadBalancer.

An example of a Service manifest of type LoadBalancer:

apiVersion: v1
kind: Service
metadata:
  name: loadbalancer-name
  labels:
    app: my-app
  annotations:
    loadbalancer.openstack.org/keep-floatingip: "true"
spec:
  type: LoadBalancer
  selector:
    app: my-app
  ports:
  - port: 80
    protocol: TCP

All additional parameters for the balancer are passed in the annotations block - the instructions specify frequently used annotations that may be useful when creating a balancer or, in some cases, for an already created balancer.

Apply the manifest:
```
kubectl apply -f <file_name>
```
Specify <file_name> - name of yaml-file with manifest for creating Service object of LoadBalancer type. For example, loadbalancer.yaml.

The created load balancer will appear in the Control Panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab.

Specify flavor and balancer type

By default, without specifying an annotation, a load balancer of type Basic with redundancy is created.

To create a balancer with a different type, use the annotation:

loadbalancer.openstack.org/flavor-id: "<flavor_id>"

Specify <flavor_id> - flavor ID. Flavor IDs correspond to load balancer types and define the number of vCPUs, RAM, and the number of load balancer instances. For example, ac18763b-1fc5-457d-9fa7-b0d339ffb336 is the ID to create a balancer with the Advanced type with redundancy in the ru-9 pool. You can view the list of load balancer flavors in all pools in the table or view the list of load balancer flavors in a specific pool through the OpenStack CLI.

You cannot change the type in a created balancer - you must create a new manifest with the desired annotation.

Create a balancer without a public IP address

By default, an unannotated balancer with a public IP address is created.

To create a balancer without a public IP address, use the annotation:

service.beta.kubernetes.io/openstack-internal-load-balancer: "true"

You cannot replace a parameter in a created balancer - you must create a new manifest with the required annotation.

Create a balancer with IP address from other subnets

By default, the balancer is created on the same network as the cluster nodes and a public IP address is allocated to it.

You can create a balancer on any other subnet - public, private, or cross-project.

Add a subnet annotation to the manifest:
```
loadbalancer.openstack.org/subnet-id: "<subnet_uuid>"
```
Specify <subnet_uuid> - subnet ID, can be viewed with openstack subnet list
Disable automatic creation of a public IP address. Add an annotation for this purpose:
```
service.beta.kubernetes.io/openstack-internal-load-balancer: "true"
```
Specify the IP address of the balancer:
```
spec:
    type: LoadBalancer
    selector:
      app: my-app
    ports:
    - port: 80
      protocol: TCP
      name: http
    loadBalancerIP: "<ip_address>"
```
Specify <ip_address> is the IP address of the balancer from the subnet you selected in step 1.

You cannot replace the annotation in the created balancer - you must create a new manifest with the desired annotation.

Add connection settings

Annotations are used to control connection settings between incoming requests and the balancer or between the balancer and servers:

maximum connections;
connection timeout for incoming requests;
connection timeout for balancer requests to servers;
inactivity timeout;
TCP wait timeout.

Connection settings are set for the balancer rule. The connection settings set in the annotations can be viewed in the control panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab → Balancers page → open the rule card → open the Advanced Rule Settings block.

Maximum connections

To specify the maximum connections, use annotation:

loadbalancer.openstack.org/connection-limit: "<value>"

Specify <value> - the maximum number of connections per second. The default value is -1 (not limited).

You can update a parameter in an already created balancer.

You can view the parameter in the Control Panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab → Balancers page → open the rule card → open the Advanced Rule Settings block → the Incoming Requests to Balancer block → the Maximum Connections field.

Connection timeout for incoming requests

To specify the connection timeout for incoming requests to the balancer, use the annotation:

loadbalancer.openstack.org/timeout-client-data: "<value>"

Specify <value> - timeout value in milliseconds. The default value is 50000.

You can update a parameter in an already created balancer.

The parameter can be viewed in the control panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab → Balancers page → open the rule card → open the Advanced rule settings block → the Incoming requests to the balancer block → the Connection timeout, ms field.

Connection timeout for balancer requests to servers

To specify the connection timeout for balancer requests to servers, use the annotation:

loadbalancer.openstack.org/timeout-member-connect: "<value>"

Specify <value> - timeout value in milliseconds. The default value is 5000.

You can update a parameter in an already created balancer.

You can view the parameter in the control panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab → Balancers page → open the rule card → open the Advanced rule settings block → the Requests from balancer to servers block → the Connection timeout, ms field.

Inactivity timeout

The inactivity timeout for balancer requests to servers is the amount of time that the current connection is considered "alive" even if no data is being transferred.

To specify the inactivity timeout, use the annotation:

loadbalancer.openstack.org/timeout-member-data: "<value>"

Specify <value> - timeout value in milliseconds. The default value is 50000.

You can update a parameter in an already created balancer.

The parameter can be viewed in the control panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab → Balancers page → open the rule card → open the Advanced Rule Settings block → open the Requests from Balancer to Servers block → the Inactivity Timeout, ms field.

TCP wait timeout

When a new TCP session is established, data is sometimes not transmitted immediately. The parameter defines the time during which the balancer waits for data transmission for inspection on an already established connection.

To specify the TCP wait timeout for balancer requests to servers, use the annotation:

loadbalancer.openstack.org/timeout-tcp-inspect: "<value>"

Specify <value> - timeout value in milliseconds. The default value is 0.

You can update a parameter in an already created balancer.

The parameter can be viewed in the control panel: in the top menu, click Products and select Cloud Servers → Balancers section → Balancers tab → Balancers page → open the rule card → open the Advanced Rule Settings block → the Requests from Balancer to Servers block → the TCP Timeout, ms field.

Enable rule checking

To enable or disable validation for rules, use the annotation:

loadbalancer.openstack.org/enable-health-monitor: "<value>"

Specify <value> - rule checking status: true - to enable checking or false - to disable checking. The default value is true.

You can update a parameter in an already created balancer.

Save the client's IP address

By default, Managed Kubernetes uses externalTrafficPolicy: Cluster. This means that the client IP address is replaced by the IP address of the cluster node. To get the client IP address, add an X-Forwarded-For header or a TCP → PROXY rule.

Add header X-Forwarded-For
Add TCP → Proxy rule

Without specifying an annotation, the balancer passes only the original body of the HTTP request to the server, replacing the client's IP address with its own.

To ensure that servers receive this information for correct operation or analysis, include an X-Forwarded-For header in the request to the server. To do this, add an annotation to the manifest:

loadbalancer.openstack.org/x-forwarded-for: "true"

The rule will use the HTTP → HTTP scheme instead of TCP → TCP. If you want to use HTTPS instead of the HTTP protocol, terminate the TLS connection.

You cannot change the type for a created balancer - you must create a new balancer with the desired annotation.

Do not use together with PROXY protocol. When a TCP → Proxy rule is added, the X-Forwarded-For header automatically goes to the service behind the balancer.

The PROXY protocol is used to transfer connection information from the source requesting the connection to the destination for which the connection was requested.

The logs of a feed to which a connection is made through a balancer with TCP → PROXY rules will show the real IP address of the connecting person, not the address of the balancer.

To create a balancer with a TCP → PROXY rule, add an annotation to the manifest:

loadbalancer.openstack.org/proxy-protocol: "true"

The X-Forwarded-For header will automatically go to the service behind the balancer. No additional annotations need to be added for it to work.

You cannot change the type for a created balancer - you must create a new balancer with the desired annotation.

Save the public IP address

To retain the public IP address when recreating the balancer, use the annotation:

loadbalancer.openstack.org/keep-floatingip: "true"

Specify this or another public IP address in the loadBalancerIP field:

spec:
  type: LoadBalancer
  selector:
    app: my-app
  ports:
  - port: 80
    protocol: TCP
    name: http
  loadBalancerIP: "<ip_address>"

You can use the annotation for an already created balancer.