Load balancing with F5 and legacy Google-provided controllers

In version 1.29 and lower, user clusters created with the loadBalancer.f5BigIP configuration deployed F5 controllers provided by Google. Because these controllers have limitations, in version 1.30 and higher, Google Distributed Cloud blocks creating clusters with the loadBalancer.f5BigIP configuration. Instead, new clusters must be configured for manual load balancing, and you need to deploy F5 controllers yourself.

This page shows how to deploy the legacy Google-provided F5 controllers for a user cluster created with Google Distributed Cloud. Although deploying these controllers is supported, we recommend that you install the latest CIS controller from F5.

Prerequisites:

• You have a user cluster with the manualLB configuration.

• You have a F5 server for the user cluster and you know its login information.

• You want to automate the process to configure virtual servers in F5 for Kubernetes Services of type LoadBalancer in your user cluster.

Step1. Prepare templates for the controllers

Get the F5 information and generate the templates.

Get F5 information

1. Set the following placeholder variables with the login information from the F5 server:

   • F5 UserName: USERNAME

   • F5 Password: PASSWORD

   • F5 Address: ADDRESS

   • F5 Partition: PARTITION

2. Set the SnatPoolName. If you aren't using SNAT, leave the placeholder variable empty:

   SnatPoolName: SNAT_POOL_NAME
   

Get the registry and version information

1. Get the onpremusercluster custom resource:

   kubectl --kubeconfig USER_CLUSTER_KUBECONFIG get onpremusercluster -oyaml -n kube-system
   

2. Copy the following fields from the onpremusercluster custom resource:

   Registry: REGISTRY (onpremusercluster.spec.registry.address)
   ImageTag: IMAGE_TAG (onpremusercluster.spec.gkeOnPremVersion)
   

Generate the templates

cat > templates.yaml << EOF
apiVersion: v1
kind: Secret
metadata:
  name: bigip-login
  namespace: kube-system
stringData:
  password: "PASSWORD"
  username: "USERNAME"
  url: "ADDRESS"
  partition: "PARTITION"
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bigip-ctlr
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: load-balancer-f5
  namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: k8s-bigip-ctlr-deployment
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: k8s-bigip-ctlr
  template:
    metadata:
      name: k8s-bigip-ctlr
      labels:
        app: k8s-bigip-ctlr
    spec:
      serviceAccountName: bigip-ctlr
      volumes:
        - name: bigip-login
          secret:
            secretName: bigip-login
      containers:
        - name: k8s-bigip-ctlr
          image: "REGISTRY/k8s-bigip-ctlr:v1.14.0-gke.28"
          resources:
            requests:
              cpu: 60m
              memory: 90Mi
          volumeMounts:
            - name: bigip-login
              readOnly: true
              mountPath: "/etc/bigip-login"
          env:
            - name: BIGIP_PARTITION
              valueFrom:
                secretKeyRef:
                  name: bigip-login
                  key: partition
          command: ["/app/bin/k8s-bigip-ctlr"]
          args: [
            # See the k8s-bigip-ctlr documentation for information about
            # all config options
            # http://clouddocs.f5.com/products/connectors/k8s-bigip-ctlr/latest
            "--http-listen-address=:9097",
            "--credentials-directory=/etc/bigip-login",
            "--bigip-partition=\$(BIGIP_PARTITION)",
            "--log-level=ERROR",
            "--pool-member-type=nodeport",
            "--manage-ingress=false",
            "--vs-snat-pool-name=SNAT_POOL_NAME"
          ]
      dnsPolicy: Default
      imagePullSecrets:
        - name: private-registry-creds
      nodeSelector:
        kubernetes.io/os: linux
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: load-balancer-f5
  namespace: kube-system
  labels:
    app: load-balancer-f5
spec:
  replicas: 1
  selector:
    matchLabels:
      app: load-balancer-f5
  template:
    metadata:
      name: load-balancer-f5
      labels:
        app: load-balancer-f5
    spec:
      serviceAccountName: load-balancer-f5
      containers:
        - name: load-balancer-f5
          image: "REGISTRY/load-balancer-f5:IMAGE_TAG"
          env:
            - name: BIGIP_PARTITION
              valueFrom:
                secretKeyRef:
                  name: bigip-login
                  key: partition
          command:
            - ./load-balancer-f5
          args:
            - "--bigip-partition=\$(BIGIP_PARTITION)"
          resources:
            requests:
              cpu: 2m
              memory: 13Mi
      imagePullSecrets:
        - name: private-registry-creds
      nodeSelector:
        kubernetes.io/os: linux
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: bigip-ctlr-clusterrole-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: bigip-ctlr-clusterrole
subjects:
  - kind: ServiceAccount
    name: bigip-ctlr
    namespace: kube-system
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: load-balancer-f5-clusterrole-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: load-balancer-f5-clusterrole
subjects:
  - kind: ServiceAccount
    name: load-balancer-f5
    namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name:
    bigip-ctlr-clusterrole
rules:
  - apiGroups: ["", "extensions"]
    resources: ["nodes", "services", "endpoints", "namespaces", "ingresses", "pods"]
    verbs: ["get", "list", "watch"]
  - apiGroups: ["", "extensions"]
    resources: ["configmaps", "events", "ingresses/status"]
    verbs: ["get", "list", "watch"]
  - apiGroups: ["", "extensions"]
    resources: ["secrets"]
    resourceNames: ["bigip-login"]
    verbs: ["get", "list", "watch"]
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name:
    load-balancer-f5-clusterrole
rules:
  - apiGroups: [""]
    resources: ["events", "nodes"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["services", "services/status"]
    verbs: ["get", "list", "watch", "patch", "update"]
  - apiGroups: [""]
    resources: ["configmaps"]
    verbs: ["get", "list", "watch",  "create", "patch", "delete"]
EOF

Step2. Apply the templates to user cluster

kubectl --kubeconfig USER_CLUSTER_KUBECONFIG apply -f templates.yaml

Note: After every upgrade of the cluster's control plane, you have to make these changes.