This deployment uses https://hub.docker.com/r/hanyifeng/alpine-ikev2-vpn container to deploy an IPsec server with strongswan on kubernetes and openshift.

strongswan.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: vpn
spec:
  selector:
    matchLabels:
      app: vpn
  serviceName: vpn
  replicas: 1
  template:
    metadata:
      labels:
        app: vpn
    spec:
      containers:
        - name: vpn
          image: hanyifeng/alpine-ikev2-vpn
          imagePullPolicy: Always
          env:
            - name: VPNUSER
              value: vpn-user
            - name: VPNPASS
              value: please_change_me
            - name: HOST_IP
              valueFrom:
                fieldRef:
                  fieldPath: status.hostIP
          securityContext:
            privileged: true <---- Its required to access kernel features due IPsec
          ports:
            - containerPort: 500
              #hostPort: 500  <--- You can enable hostPort but its not a good practice
              name: vpn-isakmp
              protocol: UDP
            - containerPort: 4500
              #hostPort: <--- You can enable hostPort but its not a good practice
              name: vpn-ike
              protocol: UDP
          volumeMounts:
            - mountPath: /lib/modules
              name: modules
      volumes:
        - name: modules
          hostPath:
            path: /lib/modules
---
# You will have to setup node ports 30500 and 30501 at your client 
# Or use something like nginx with streams enabled:
# to forward udp traffic to port 500 and 4500
# https://nginx.org/en/docs/stream/ngx_stream_core_module.html
# Rememer that nginx does not supports domain based reverse proxy.
      
kind: Service
apiVersion: v1
metadata:
  name: vpn
spec:
  selector:
    app: vpn
  type: NodePort
  ports:
    - name: vpn-isakmp
      port: 500
      targetPort: vpn-isakmp
      protocol: UDP
      nodePort: 30500  
    - name: vpn-ike
      port: 4500
      targetPort: vpn-ike
      protocol: UDP
      nodePort: 30501