Chapter 22. Load balancing with MetalLB

22.1. About MetalLB and the MetalLB Operator

As a cluster administrator, you can add the MetalLB Operator to your cluster so that when a service of type LoadBalancer is added to the cluster, MetalLB can add a fault-tolerant external IP address for the service. The external IP address is added to the host network for your cluster.

22.1.1. When to use MetalLB

Using MetalLB is valuable when you have a bare-metal cluster, or an infrastructure that is like bare metal, and you want fault-tolerant access to an application through an external IP address.

You must configure your networking infrastructure to ensure that network traffic for the external IP address is routed from clients to the host network for the cluster.

After deploying MetalLB with the MetalLB Operator, when you add a service of type LoadBalancer, MetalLB provides a platform-native load balancer.

22.1.2. MetalLB Operator custom resources

The MetalLB Operator monitors its own namespace for two custom resources:

MetalLB
When you add a MetalLB custom resource to the cluster, the MetalLB Operator deploys MetalLB on the cluster. The Operator only supports a single instance of the custom resource. If the instance is deleted, the Operator removes MetalLB from the cluster.
AddressPool
MetalLB requires one or more pools of IP addresses that it can assign to a service when you add a service of type LoadBalancer. When you add an AddressPool custom resource to the cluster, the MetalLB Operator configures MetalLB so that it can assign IP addresses from the pool. An address pool includes a list of IP addresses. The list can be a single IP address, a range specified in CIDR notation, a range specified as a starting and ending address separated by a hyphen, or a combination of the three. An address pool requires a name. The documentation uses names like doc-example, doc-example-reserved, and doc-example-ipv6. An address pool specifies whether MetalLB can automatically assign IP addresses from the pool or whether the IP addresses are reserved for services that explicitly specify the pool by name.

After you add the MetalLB custom resource to the cluster and the Operator deploys MetalLB, the MetalLB software components, controller and speaker, begin running.

22.1.3. MetalLB software components

When you install the MetalLB Operator, the metallb-operator-controller-manager deployment starts a pod. The pod is the implementation of the Operator. The pod monitors for changes to the MetalLB custom resource and AddressPool custom resources.

When the Operator starts an instance of MetalLB, it starts a controller deployment and a speaker daemon set.

controller
The Operator starts the deployment and a single pod. When you add a service of type LoadBalancer, Kubernetes uses the controller to allocate an IP address from an address pool.
speaker

The Operator starts a daemon set with one speaker pod for each node in your cluster.

For layer 2 mode, after the controller allocates an IP address for the service, each speaker pod determines if it is on the same node as an endpoint for the service. An algorithm that involves hashing the node name and the service name is used to select a single speaker pod to announce the load balancer IP address. The speaker uses Address Resolution Protocol (ARP) to announce IPv4 addresses and Neighbor Discovery Protocol (NDP) to announce IPv6 addresses.

Requests for the load balancer IP address are routed to the node with the speaker that announces the IP address. After the node receives the packets, the service proxy routes the packets to an endpoint for the service. The endpoint can be on the same node in the optimal case, or it can be on another node. The service proxy chooses an endpoint each time a connection is established.

22.1.4. MetalLB concepts for layer 2 mode

In layer 2 mode, the speaker pod on one node announces the external IP address for a service to the host network. From a network perspective, the node appears to have multiple IP addresses assigned to a network interface.

The speaker pod responds to ARP requests for IPv4 services and NDP requests for IPv6.

In layer 2 mode, all traffic for a service IP address is routed through one node. After traffic enters the node, the service proxy for the CNI network provider distributes the traffic to all the pods for the service.

Because all traffic for a service enters through a single node in layer 2 mode, in a strict sense, MetalLB does not implement a load balancer for layer 2. Rather, MetalLB implements a failover mechanism for layer 2 so that when a speaker pod becomes unavailable, a speaker pod on a different node can announce the service IP address.

When a node becomes unavailable, failover is automatic. The speaker pods on the other nodes detect that a node is unavailable and a new speaker pod and node take ownership of the service IP address from the failed node.

Conceptual diagram for MetalLB and layer 2 mode

The preceding graphic shows the following concepts related to MetalLB:

  • An application is available through a service that has a cluster IP on the 172.130.0.0/16 subnet. That IP address is accessible from inside the cluster. The service also has an external IP address that MetalLB assigned to the service, 192.168.100.200.
  • Nodes 1 and 3 have a pod for the application.
  • The speaker daemon set runs a pod on each node. The MetalLB Operator starts these pods.
  • Each speaker pod is a host-networked pod. The IP address for the pod is identical to the IP address for the node on the host network.
  • The speaker pod on node 1 uses ARP to announce the external IP address for the service, 192.168.100.200. The speaker pod that announces the external IP address must be on the same node as an endpoint for the service and the endpoint must be in the Ready condition.
  • Client traffic is routed to the host network and connects to the 192.168.100.200 IP address. After traffic enters the node, the service proxy sends the traffic to the application pod on the same node or another node according to the external traffic policy that you set for the service.
  • If node 1 becomes unavailable, the external IP address fails over to another node. On another node that has an instance of the application pod and service endpoint, the speaker pod begins to announce the external IP address, 192.168.100.200 and the new node receives the client traffic. In the diagram, the only candidate is node 3.

22.1.4.1. Layer 2 and external traffic policy

With layer 2 mode, one node in your cluster receives all the traffic for the service IP address. How your cluster handles the traffic after it enters the node is affected by the external traffic policy.

cluster

This is the default value for spec.externalTrafficPolicy.

With the cluster traffic policy, after the node receives the traffic, the service proxy distributes the traffic to all the pods in your service. This policy provides uniform traffic distribution across the pods, but it obscures the client IP address and it can appear to the application in your pods that the traffic originates from the node rather than the client.

local

With the local traffic policy, after the node receives the traffic, the service proxy only sends traffic to the pods on the same node. For example, if the speaker pod on node A announces the external service IP, then all traffic is sent to node A. After the traffic enters node A, the service proxy only sends traffic to pods for the service that are also on node A. Pods for the service that are on additional nodes do not receive any traffic from node A. Pods for the service on additional nodes act as replicas in case failover is needed.

This policy does not affect the client IP address. Application pods can determine the client IP address from the incoming connections.

22.1.5. Limitations and restrictions

22.1.5.1. Support for layer 2 only

When you install and configure MetalLB on OpenShift Container Platform 4.9 with the MetalLB Operator, support is restricted to layer 2 mode only. In comparison, the open source MetalLB project offers load balancing for layer 2 mode and a mode for layer 3 that uses border gateway protocol (BGP).

22.1.5.2. Support for single stack networking

Although you can specify IPv4 addresses and IPv6 addresses in the same address pool, MetalLB only assigns one IP address for the load balancer.

When MetalLB is deployed on a cluster that is configured for dual-stack networking, MetalLB assigns one IPv4 or IPv6 address for the load balancer, depending on the IP address family of the cluster IP for the service. For example, if the cluster IP of the service is IPv4, then MetalLB assigns an IPv4 address for the load balancer. MetalLB does not assign an IPv4 and an IPv6 address simultaneously.

IPv6 is only supported for clusters that use the OVN-Kubernetes network provider.

22.1.5.3. Infrastructure considerations for MetalLB

MetalLB is primarily useful for on-premise, bare metal installations because these installations do not include a native load-balancer capability. In addition to bare metal installations, installations of OpenShift Container Platform on some infrastructures might not include a native load-balancer capability. For example, the following infrastructures can benefit from adding the MetalLB Operator:

  • Bare metal
  • VMware vSphere

MetalLB Operator and MetalLB are supported with the OpenShift SDN and OVN-Kubernetes network providers.

22.1.5.4. Limitations for layer 2 mode

22.1.5.4.1. Single-node bottleneck

MetalLB routes all traffic for a service through a single node, the node can become a bottleneck and limit performance.

Layer 2 mode limits the ingress bandwidth for your service to the bandwidth of a single node. This is a fundamental limitation of using ARP and NDP to direct traffic.

22.1.5.4.2. Slow failover performance

Failover between nodes depends on cooperation from the clients. When a failover occurs, MetalLB sends gratuitous ARP packets to notify clients that the MAC address associated with the service IP has changed.

Most client operating systems handle gratuitous ARP packets correctly and update their neighbor caches promptly. When clients update their caches quickly, failover completes within a few seconds. Clients typically fail over to a new node within 10 seconds. However, some client operating systems either do not handle gratuitous ARP packets at all or have outdated implementations that delay the cache update.

Recent versions of common operating systems such as Windows, macOS, and Linux implement layer 2 failover correctly. Issues with slow failover are not expected except for older and less common client operating systems.

To minimize the impact from a planned failover on outdated clients, keep the old node running for a few minutes after flipping leadership. The old node can continue to forward traffic for outdated clients until their caches refresh.

During an unplanned failover, the service IPs are unreachable until the outdated clients refresh their cache entries.

22.1.5.5. Incompatibility with IP failover

MetalLB is incompatible with the IP failover feature. Before you install the MetalLB Operator, remove IP failover.

22.1.6. Additional resources

22.2. Installing the MetalLB Operator

As a cluster administrator, you can add the MetallB Operator so that the Operator can manage the lifecycle for an instance of MetalLB on your cluster.

The installation procedures use the metallb-system namespace. You can install the Operator and configure custom resources in a different namespace. The Operator starts MetalLB in the same namespace that the Operator is installed in.

MetalLB and IP failover are incompatible. If you configured IP failover for your cluster, perform the steps to remove IP failover before you install the Operator.

22.2.1. Installing from OperatorHub using the web console

You can install and subscribe to an Operator from OperatorHub using the OpenShift Container Platform web console.

Procedure

  1. Navigate in the web console to the Operators → OperatorHub page.
  2. Scroll or type a keyword into the Filter by keyword box to find the Operator you want. For example, type metallb to find the MetalLB Operator.

    You can also filter options by Infrastructure Features. For example, select Disconnected if you want to see Operators that work in disconnected environments, also known as restricted network environments.

  3. Select the Operator to display additional information.

    Note

    Choosing a Community Operator warns that Red Hat does not certify Community Operators; you must acknowledge the warning before continuing.

  4. Read the information about the Operator and click Install.
  5. On the Install Operator page:

    1. Select an Update Channel (if more than one is available).
    2. Select Automatic or Manual approval strategy, as described earlier.
  6. Click Install to make the Operator available to the selected namespaces on this OpenShift Container Platform cluster.

    1. If you selected a Manual approval strategy, the upgrade status of the subscription remains Upgrading until you review and approve the install plan.

      After approving on the Install Plan page, the subscription upgrade status moves to Up to date.

    2. If you selected an Automatic approval strategy, the upgrade status should resolve to Up to date without intervention.
  7. After the upgrade status of the subscription is Up to date, select Operators → Installed Operators to verify that the cluster service version (CSV) of the installed Operator eventually shows up. The Status should ultimately resolve to InstallSucceeded in the relevant namespace.

    Note

    For the All namespaces…​ installation mode, the status resolves to InstallSucceeded in the openshift-operators namespace, but the status is Copied if you check in other namespaces.

    If it does not:

    1. Check the logs in any pods in the openshift-operators project (or other relevant namespace if A specific namespace…​ installation mode was selected) on the Workloads → Pods page that are reporting issues to troubleshoot further.

22.2.2. Installing from OperatorHub using the CLI

Instead of using the OpenShift Container Platform web console, you can install an Operator from OperatorHub using the CLI. Use the oc command to create or update a Subscription object.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in as a user with cluster-admin privileges.

Procedure

  1. Confirm that the MetalLB Operator is available:

    $ oc get packagemanifests -n openshift-marketplace metallb-operator

    Example output

    NAME               CATALOG                AGE
    metallb-operator   Red Hat Operators      9h

  2. Create the metallb-system namespace:

    $ cat << EOF | oc apply -f -
    apiVersion: v1
    kind: Namespace
    metadata:
      name: metallb-system
    EOF
  3. Create an Operator group custom resource in the namespace:

    $ cat << EOF | oc apply -f -
    apiVersion: operators.coreos.com/v1
    kind: OperatorGroup
    metadata:
      name: metallb-operator
      namespace: metallb-system
    spec:
      targetNamespaces:
      - metallb-system
    EOF
  4. Confirm the Operator group is installed in the namespace:

    $ oc get operatorgroup -n metallb-system

    Example output

    NAME               AGE
    metallb-operator   14m

  5. Subscribe to the MetalLB Operator.

    1. Run the following command to get the OpenShift Container Platform major and minor version. You use the values to set the channel value in the next step.

      $ OC_VERSION=$(oc version -o yaml | grep openshiftVersion | \
          grep -o '[0-9]*[.][0-9]*' | head -1)
    2. To create a subscription custom resource for the Operator, enter the following command:

      $ cat << EOF| oc apply -f -
      apiVersion: operators.coreos.com/v1alpha1
      kind: Subscription
      metadata:
        name: metallb-operator-sub
        namespace: metallb-system
      spec:
        channel: "${OC_VERSION}"
        name: metallb-operator
        source: redhat-operators
        sourceNamespace: openshift-marketplace
      EOF
  6. Confirm the install plan is in the namespace:

    $ oc get installplan -n metallb-system

    Example output

    NAME            CSV                                   APPROVAL    APPROVED
    install-wzg94   metallb-operator.4.9.0-nnnnnnnnnnnn   Automatic   true

  7. To verify that the Operator is installed, enter the following command:

    $ oc get clusterserviceversion -n metallb-system \
      -o custom-columns=Name:.metadata.name,Phase:.status.phase

    Example output

    Name                                  Phase
    metallb-operator.4.9.0-nnnnnnnnnnnn   Succeeded

22.2.3. Starting MetalLB on your cluster

After you install the Operator, you need to configure a single instance of a MetalLB custom resource. After you configure the custom resource, the Operator starts MetalLB on your cluster.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in as a user with cluster-admin privileges.
  • Install the MetalLB Operator.

Procedure

  1. Create a single instance of a MetalLB custom resource:

    $ cat << EOF | oc apply -f -
    apiVersion: metallb.io/v1beta1
    kind: MetalLB
    metadata:
      name: metallb
      namespace: metallb-system
    EOF

Verification

Confirm that the deployment for the MetalLB controller and the daemon set for the MetalLB speaker are running.

  1. Check that the deployment for the controller is running:

    $ oc get deployment -n metallb-system controller

    Example output

    NAME         READY   UP-TO-DATE   AVAILABLE   AGE
    controller   1/1     1            1           11m

  2. Check that the daemon set for the speaker is running:

    $ oc get daemonset -n metallb-system speaker

    Example output

    NAME      DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR            AGE
    speaker   6         6         6       6            6           kubernetes.io/os=linux   18m

    The example output indicates 6 speaker pods. The number of speaker pods in your cluster might differ from the example output. Make sure the output indicates one pod for each node in your cluster.

22.2.4. Next steps

22.3. Configuring MetalLB address pools

As a cluster administrator, you can add, modify, and delete address pools. The MetalLB Operator uses the address pool custom resources to set the IP addresses that MetalLB can assign to services.

22.3.1. About the address pool custom resource

The fields for the address pool custom resource are described in the following table.

Table 22.1. MetalLB address pool custom resource

FieldTypeDescription

metadata.name

string

Specifies the name for the address pool. When you add a service, you can specify this pool name in the metallb.universe.tf/address-pool annotation to select an IP address from a specific pool. The names doc-example, silver, and gold are used throughout the documentation.

metadata.namespace

string

Specifies the namespace for the address pool. Specify the same namespace that the MetalLB Operator uses.

spec.protocol

string

Specifies the protocol for announcing the load balancer IP address to peer nodes. The only supported value is layer2.

spec.autoAssign

boolean

Optional: Specifies whether MetalLB automatically assigns IP addresses from this pool. Specify false if you want explicitly request an IP address from this pool with the metallb.universe.tf/address-pool annotation. The default value is true.

spec.addresses

array

Specifies a list of IP addresses for MetalLB to assign to services. You can specify multiple ranges in a single pool. Specify each range in CIDR notation or as starting and ending IP addresses separated with a hyphen.

22.3.2. Configuring an address pool

As a cluster administrator, you can add address pools to your cluster to control the IP addresses that MetaLLB can assign to load-balancer services.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in as a user with cluster-admin privileges.

Procedure

  1. Create a file, such as addresspool.yaml, with content like the following example:

    apiVersion: metallb.io/v1alpha1
    kind: AddressPool
    metadata:
      namespace: metallb-system
      name: doc-example
    spec:
      protocol: layer2
      addresses:
      - 203.0.113.1-203.0.113.10
      - 203.0.113.65-203.0.113.75
  2. Apply the configuration for the address pool:

    $ oc apply -f addresspool.yaml

Verification

  • View the address pool:

    $ oc describe -n metallb-system addresspool doc-example

    Example output

    Name:         doc-example
    Namespace:    metallb-system
    Labels:       <none>
    Annotations:  <none>
    API Version:  metallb.io/v1alpha1
    Kind:         AddressPool
    Metadata:
      ...
    Spec:
      Addresses:
        203.0.113.1-203.0.113.10
        203.0.113.65-203.0.113.75
      Auto Assign:  true
      Protocol:     layer2
    Events:         <none>

Confirm that the address pool name, such as doc-example, and the IP address ranges appear in the output.

22.3.3. Example address pool configurations

22.3.3.1. Example: IPv4 and CIDR ranges

You can specify a range of IP addresses in CIDR notation. You can combine CIDR notation with the notation that uses a hyphen to separate lower and upper bounds.

apiVersion: metallb.io/v1beta1
kind: AddressPool
metadata:
  name: doc-example-cidr
  namespace: metallb-system
spec:
  protocol: layer2
  addresses:
  - 192.168.100.0/24
  - 192.168.200.0/24
  - 192.168.255.1-192.168.255.5

22.3.3.2. Example: Reserve IP addresses

You can set the autoAssign field to false to prevent MetalLB from automatically assigning the IP addresses from the pool. When you add a service, you can request a specific IP address from the pool or you can specify the pool name in an annotation to request any IP address from the pool.

apiVersion: metallb.io/v1beta1
kind: AddressPool
metadata:
  name: doc-example-reserved
  namespace: metallb-system
spec:
  protocol: layer2
  addresses:
  - 10.0.100.0/28
  autoAssign: false

22.3.3.3. Example: IPv6 address pool

You can add address pools that use IPv6. The following example shows a single IPv6 range. However, you can specify multiple ranges in the addresses list, just like several IPv4 examples.

apiVersion: metallb.io/v1beta1
kind: AddressPool
metadata:
  name: doc-example-ipv6
  namespace: metallb-system
spec:
  protocol: layer2
  addresses:
  - 2002:2:2::1-2002:2:2::100

22.3.4. Next steps

22.4. Configuring services to use MetalLB

As a cluster administrator, when you add a service of type LoadBalancer, you can control how MetalLB assigns an IP address.

22.4.1. Request a specific IP address

Like some other load-balancer implementations, MetalLB accepts the spec.loadBalancerIP field in the service specification.

If the requested IP address is within a range from any address pool, MetalLB assigns the requested IP address. If the requested IP address is not within any range, MetalLB reports a warning.

Example service YAML for a specific IP address

apiVersion: v1
kind: Service
metadata:
  name: <service_name>
  annotations:
    metallb.universe.tf/address-pool: <address_pool_name>
spec:
  selector:
    <label_key>: <label_value>
  ports:
    - port: 8080
      targetPort: 8080
      protocol: TCP
  type: LoadBalancer
  loadBalancerIP: <ip_address>

If MetalLB cannot assign the requested IP address, the EXTERNAL-IP for the service reports <pending> and running oc describe service <service_name> includes an event like the following example.

Example event when MetalLB cannot assign a requested IP address

  ...
Events:
  Type     Reason            Age    From                Message
  ----     ------            ----   ----                -------
  Warning  AllocationFailed  3m16s  metallb-controller  Failed to allocate IP for "default/invalid-request": "4.3.2.1" is not allowed in config

22.4.2. Request an IP address from a specific pool

To assign an IP address from a specific range, but you are not concerned with the specific IP address, then you can use the metallb.universe.tf/address-pool annotation to request an IP address from the specified address pool.

Example service YAML for an IP address from a specific pool

apiVersion: v1
kind: Service
metadata:
  name: <service_name>
  annotations:
    metallb.universe.tf/address-pool: <address_pool_name>
spec:
  selector:
    <label_key>: <label_value>
  ports:
    - port: 8080
      targetPort: 8080
      protocol: TCP
  type: LoadBalancer

If the address pool that you specify for <address_pool_name> does not exist, MetalLB attempts to assign an IP address from any pool that permits automatic assignment.

22.4.3. Accept any IP address

By default, address pools are configured to permit automatic assignment. MetalLB assigns an IP address from these address pools.

To accept any IP address from any pool that is configured for automatic assignment, no special annotation or configuration is required.

Example service YAML for accepting any IP address

apiVersion: v1
kind: Service
metadata:
  name: <service_name>
spec:
  selector:
    <label_key>: <label_value>
  ports:
    - port: 8080
      targetPort: 8080
      protocol: TCP
  type: LoadBalancer

22.4.4. Share a specific IP address

By default, services do not share IP addresses. However, if you need to colocate services on a single IP address, you can enable selective IP sharing by adding the metallb.universe.tf/allow-shared-ip annotation to the services.

apiVersion: v1
kind: Service
metadata:
  name: service-http
  annotations:
    metallb.universe.tf/address-pool: doc-example
    metallb.universe.tf/allow-shared-ip: "web-server-svc"  1
spec:
  ports:
    - name: http
      port: 80  2
      protocol: TCP
      targetPort: 8080
  selector:
    <label_key>: <label_value>  3
  type: LoadBalancer
  loadBalancerIP: 172.31.249.7  4
---
apiVersion: v1
kind: Service
metadata:
  name: service-https
  annotations:
    metallb.universe.tf/address-pool: doc-example
    metallb.universe.tf/allow-shared-ip: "web-server-svc"  5
spec:
  ports:
    - name: https
      port: 443  6
      protocol: TCP
      targetPort: 8080
  selector:
    <label_key>: <label_value>  7
  type: LoadBalancer
  loadBalancerIP: 172.31.249.7  8
1 5
Specify the same value for the metallb.universe.tf/allow-shared-ip annotation. This value is referred to as the sharing key.
2 6
Specify different port numbers for the services.
3 7
Specify identical pod selectors if you must specify externalTrafficPolicy: local so the services send traffic to the same set of pods. If you use the cluster external traffic policy, then the pod selectors do not need to be identical.
4 8
Optional: If you specify the three preceding items, MetalLB might colocate the services on the same IP address. To ensure that services share an IP address, specify the IP address to share.

By default, Kubernetes does not allow multiprotocol load balancer services. This limitation would normally make it impossible to run a service like DNS that needs to listen on both TCP and UDP. To work around this limitation of Kubernetes with MetalLB, create two services:

  • For one service, specify TCP and for the second service, specify UDP.
  • In both services, specify the same pod selector.
  • Specify the same sharing key and spec.loadBalancerIP value to colocate the TCP and UDP services on the same IP address.

22.4.5. Configuring a service with MetalLB

You can configure a load-balancing service to use an external IP address from an address pool.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Install the MetalLB Operator and start MetalLB.
  • Configure at least one address pool.
  • Configure your network to route traffic from the clients to the host network for the cluster.

Procedure

  1. Create a <service_name>.yaml file. In the file, ensure that the spec.type field is set to LoadBalancer.

    Refer to the examples for information about how to request the external IP address that MetalLB assigns to the service.

  2. Create the service:

    $ oc apply -f <service_name>.yaml

    Example output

    service/<service_name> created

Verification

  • Describe the service:

    $ oc describe service <service_name>

    Example output

    Name:                     <service_name>
    Namespace:                default
    Labels:                   <none>
    Annotations:              metallb.universe.tf/address-pool: doc-example  <.>
    Selector:                 app=service_name
    Type:                     LoadBalancer  <.>
    IP Family Policy:         SingleStack
    IP Families:              IPv4
    IP:                       10.105.237.254
    IPs:                      10.105.237.254
    LoadBalancer Ingress:     192.168.100.5  <.>
    Port:                     <unset>  80/TCP
    TargetPort:               8080/TCP
    NodePort:                 <unset>  30550/TCP
    Endpoints:                10.244.0.50:8080
    Session Affinity:         None
    External Traffic Policy:  Cluster
    Events:  <.>
      Type    Reason        Age                From             Message
      ----    ------        ----               ----             -------
      Normal  nodeAssigned  32m (x2 over 32m)  metallb-speaker  announcing from node "<node_name>"

    <.> The annotation is present if you request an IP address from a specific pool. <.> The service type must indicate LoadBalancer. <.> The load-balancer ingress field indicates the external IP address if the service is assigned correctly. <.> The events field indicates the node name that is assigned to announce the external IP address. If you experience an error, the events field indicates the reason for the error.