StarlingX MetalLB App installation guide

app-metallb is a StarlingX containerized application that deploys MetalLB to provide Kubernetes LoadBalancer services for clusters running on bare metal or non-cloud environments.

MetalLB integrates with the StarlingX networking model to advertise service IP addresses using either BGP or Layer 2 (ARP/NDP) mechanisms, enabling external connectivity to Kubernetes services without relying on a cloud provider load balancer.

Source

Tarball Package

Get the .tgz file located at

   /usr/local/share/applications/helm/

Or build it yourself using the Debian Build environment

   build-pkgs -c -p metallb-helm,python3-k8sapp-metallb,stx-metallb-helm

Deployment Architecture

MetalLB is deployed into the metallb-system namespace and consists of:

metallb-controller Deployment
metallb-speaker DaemonSet
Optional FRR containers when BGP mode is enabled

In BGP mode, the speaker establishes BGP sessions with configured peers and advertises service IPs as host routes.

Usage

Apply the app

   [root@controller-0 sysadmin(keystone_admin)]# system application-apply metallb

Verify MetalLB controller and speaker pods are running

   [root@controller-0 sysadmin(keystone_admin)]# kubectl get pods -n metallb-system
   NAME                                 READY   STATUS    RESTARTS   AGE
   metallb-controller-bbfd4845b-gknmx   1/1     Running   0          75s
   metallb-speaker-tfwmz                1/1     Running   0          75s

Simple L2 mode example

Apply the configuration for the IPAddressPool and "L2Advertisement".

   [root@controller-0 sysadmin(keystone_admin)]# cat metallb-l2.yaml
   apiVersion: metallb.io/v1beta1
   kind: IPAddressPool
   metadata:
     name: l2-pool
     namespace: metallb-system
   spec:
     addresses: ["192.168.206.200-192.168.206.210"]
     avoidBuggyIPs: true
   ---
   apiVersion: metallb.io/v1beta1
   kind: L2Advertisement
   metadata:
     name: metallb-adv
     namespace: metallb-system
   spec:
     ipAddressPools:
       - l2-pool

Apply a simple nginx service that a host outside the cluster can access

   [root@controller-0 sysadmin(keystone_admin)]# cat nginx.yaml
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx-test
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx-test
     template:
       metadata:
         labels:
           app: nginx-test
       spec:
         containers:
         - name: nginx
           image: nginx:latest
           ports:
           - containerPort: 80
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: nginx-service
   spec:
     type: LoadBalancer
     selector:
       app: nginx-test
     ports:
     - port: 80
       targetPort: 80

Notice that the MetalLB controller assigns the nginx service an external IP while the speaker is announcing that IP.

   [root@controller-0 sysadmin(keystone_admin)]# kubectl get svc nginx-service
   NAME            TYPE           CLUSTER-IP       EXTERNAL-IP       PORT(S)        AGE
   nginx-service   LoadBalancer   10.111.148.132   192.168.206.200   80:30966/TCP   6s

   [root@controller-0 sysadmin(keystone_admin)]# kubectl describe svc nginx-service
   ...
   Events:
     Type    Reason        Age   From                Message
     ----    ------        ----  ----                -------
     Normal  IPAllocated   23s   metallb-controller  Assigned IP ["192.168.206.200"]
     Normal  nodeAssigned  12s   metallb-speaker     announcing from node "controller-0" with protocol "layer2"

StarlingX/Containers/Applications/app-metallb

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