How Can I Disable SSH On My LKE Worker Nodes?

You can automatically stop and disable SSH across all present and future worker nodes by utilizing a daemonset like this:

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: disable-ssh
  namespace: kube-system
spec:
  selector:
    matchLabels:
      run: disable-ssh
  template:
    metadata:
      labels:
        run: disable-ssh
    spec:
      # needs hostPID to use systemctl
      hostPID: true
      # tolerate everyting
      tolerations:
      - operator: Exists
      containers:
      - name: startup-script
        image: gcr.io/google-containers/startup-script:v1
        securityContext:
          privileged: true
        env:
        - name: STARTUP_SCRIPT
          value: |
            #!/bin/bash
            set -o errexit
            set -o xtrace
            if systemctl is-active ssh.service; then
              systemctl stop ssh.service
            fi
            if systemctl is-enabled ssh.service; then
              systemctl disable ssh.service
            fi