#Configure Alauda Container Platform Load Balancer

#Prerequisites

Please ensure that you have read the Installation documentation before proceeding.

#Configure MetalLB Components

Configure the MetalLB custom resource's spec.controllerNodeSelector, spec.controllerTolerations, spec.nodeSelector, and spec.speakerTolerations fields after installing the Cluster Plugin. See Configure Component Placement for the configuration example and the relationship with L2Advertisement.spec.nodeSelectors.

To adjust the controller and speaker log level, set spec.logLevel on the same resource. See Adjust Log Level for supported values.

#Configure an External IP Pool by using the web console

1. Go to Administrator.

2. In the left navigation bar, click Networking > External IPs > External IP Pools.

3. Click Create External IP Pools.

4. Refer to the following instructions to configure certain parameters.

   Parameter	Description
   Type	L2: Communication and forwarding based on MAC addresses, suitable for small-scale or local area networks that require simple and fast layer 2 switching, with advantages in simple configuration and low latency. BGP (Alpha): Routing and forwarding based on IP addresses, using BGP protocol to exchange routing information, suitable for large-scale networks requiring complex routing across multiple autonomous systems, with advantages in high scalability and reliability.
   IP Resources	Support input in CIDR and IP range formats. Click Add to support multiple entries, examples as follows: CIDR: 192.168.1.1/24. IP Range: 192.168.2.1 ~ 192.168.2.255.
   Available Nodes	In L2 mode, available nodes are those used to carry all VIP traffic; in BGP mode, available nodes are those used to carry VIPs, establish BGP connections with peers, and announce routes externally. Node Name: Select available nodes based on node names. Label Selector: Select available nodes based on labels. Show Node Details: View final available nodes in a list format. Note: When using BGP type, the available nodes are the next-hop nodes; ensure that the selected available nodes are a subset of the BGP Connection Nodes. You can configure either the label selector or the node name separately to choose available nodes; if both are configured simultaneously, the final available nodes are the intersection of both.
   BGP Peers	Select BGP peers; please refer to BGP Peers for specific configurations.

5. Click Create.

#Configure BGP Peers by using the web console

1. Go to Administrator.

2. In the left navigation bar, click Networking > External IPs > BGP Peer.

3. Click Create BGP Peer.

4. Refer to the instructions below to configure the parameters.

   Parameter	Description
   Local AS Number	The AS number of the AS where the BGP-connected node resides. Note: If there are no special requirements, it is recommended to use an IBGP configuration, meaning the local AS number should be consistent with the peer AS number.
   Peer AS Number	The AS number of the AS where the BGP peer resides.
   Peer IP	The IP address of the BGP peer, which must be a valid IP address capable of establishing a BGP connection.
   Local IP	The IP address of the BGP-connected node. When the BGP-connected node has multiple IPs, select the specified local IP to establish a BGP connection with the peer.
   Peer Port	The port number of the BGP peer.
   BGP-Connected Node	The node that establishes the BGP connection. If this parameter is not configured, all nodes will establish BGP connections.
   eBGP Multi-Hop	Allows the establishment of BGP sessions between BGP routers that are not directly connected. When this feature is enabled, the default TTL value of BGP packets is 5, allowing the establishment of BGP peer relationships across multiple intermediate network devices, making network design more flexible.
   RouterID	A 32-bit numeric value (usually represented in dotted-decimal format, similar to IPv4 address format) used to uniquely identify a BGP router in the BGP network, generally used for establishing BGP neighbor relationships, detecting routing loops, selecting optimal paths, and troubleshooting network issues.

5. Click Create.

Note: When you use BGP mode, allow TCP port 179 between each BGP peer and the MetalLB speaker nodes. If you configure a custom peer port, allow the configured port instead.

#Configure an External IP Pool with L2Advertisement or BGPAdvertisement by using the CLI

# ippool-with-L2advertisement.yaml
kind: IPAddressPool
apiVersion: metallb.io/v1beta1
metadata:
  name: test-ippool
  namespace: metallb-system
spec:
  addresses:
    - 13.1.1.1/24
  avoidBuggyIPs: true
---
kind: L2Advertisement
apiVersion: metallb.io/v1beta1
metadata:
  name: test-ippool
  namespace: metallb-system
spec:
  ipAddressPools:
    - test-ippool
  nodeSelectors:
    - matchLabels: {}
      matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
            - 192.168.66.210

BGP mode

# ippool-with-bgpadvertisement.yaml
kind: IPAddressPool
apiVersion: metallb.io/v1beta1
metadata:
  name: test-pool-bgp
  namespace: metallb-system
spec:
  addresses:
    - 4.4.4.3/23
  avoidBuggyIPs: true
---
kind: BGPAdvertisement
apiVersion: metallb.io/v1beta1
metadata:
  name: test-pool-bgp
  namespace: metallb-system
spec:
  ipAddressPools:
    - test-pool-bgp
  nodeSelectors:
    - matchLabels:
        alertmanager: 'true'
  peers:
    - test-bgp-example

kubectl apply -f ippool-with-L2advertisement.yaml -f ippool-with-bgpadvertisement.yaml

#Monitor MetalLB

After you configure MetalLB, you can use the built-in dashboard and monitoring metrics to observe IP address allocation and BGP session status.

Note: The built-in MetalLB dashboard is available in ACP 4.4.

#View the built-in MetalLB dashboard

1. Go to Operations Center.

2. In the left navigation bar, click Monitoring > Monitoring Dashboards.

3. Search for MetalLB, and then open the dashboard.

The built-in MetalLB dashboard includes the following panels:

#Access the MetalLB metrics endpoint

MetalLB exposes controller and speaker metrics through monitor Services in the metallb-system namespace. You can access these metrics from inside the cluster to confirm whether the components expose metrics correctly.

Check the MetalLB monitor Services:

kubectl get svc -n metallb-system | grep monitor

Check the Service endpoints:

kubectl get endpointslice -n metallb-system -l kubernetes.io/service-name=controller-monitor-service
kubectl get endpointslice -n metallb-system -l kubernetes.io/service-name=speaker-monitor-service

The endpoint addresses use port 17472 by default.

Query the controller metrics endpoint from inside the cluster:

curl -s http://<controller-endpoint-address>:17472/metrics | grep '^metallb_'

Query a speaker metrics endpoint from inside the cluster:

curl -s http://<speaker-endpoint-address>:17472/metrics | grep '^metallb_'

If the command returns MetalLB metrics, the component metrics endpoint is available.

#MetalLB metrics reference

The built-in MetalLB dashboard uses the following metrics:

#Troubleshooting MetalLB

To see more Troubleshooting MetalLB

#Trademark Notice

MetalLB™ is a trademark of The Linux Foundation.

Alauda is an independent vendor. This product is not affiliated with, endorsed by, or sponsored by The Linux Foundation. All trademarks are the property of their respective owners and are used here for identification purposes only.