[BESU-507] Resolve crashing NAT detectors on GKE

[matkt]

Signed-off-by: Karim TAAM [email protected]

PR description

Issue : #507

• Resolve the NatManager crash when besu is launched on GKE.
• Improved logs when switching to the fallback mode

It is no longer necessary in KUBERNETES to create a volume and to move the kubeconfig file in this volume

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app.kubernetes.io/name: besu
    app.kubernetes.io/release: "1.0.0"
  name: besu
spec:
  ports:
  - name: "json-rpc"
    port: 8545
    targetPort: 8545
  - name: "rlpx"
    port: 30303
    targetPort: 30303
  selector:
    app.kubernetes.io/name: besu
    app.kubernetes.io/release: "1.0.0"
  type: LoadBalancer

You can check the service thanks to this command

kubectl describe services besu

Name:                     besu
Namespace:                default
Labels:                   app.kubernetes.io/name=besu
                          app.kubernetes.io/release=1.0.0
Annotations:              kubectl.kubernetes.io/last-applied-configuration:
                            {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app.kubernetes.io/name":"besu","app.kubernetes.io/release":"1....
Selector:                 app.kubernetes.io/name=besu,app.kubernetes.io/release=1.0.0
Type:                     LoadBalancer
IP:                       --------
LoadBalancer Ingress:     ***<IP>***

And then deploy Besu

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: besu-config
  labels:
    app.kubernetes.io/name: besu
    app.kubernetes.io/release: 1.0.0
data:
  BESU_LOGGING: "INFO"
  BESU_NETWORK: "dev"
  BESU_P2P_ENABLED: "true"
  BESU_RPC_HTTP_ENABLED: "true"
  BESU_RPC_HTTP_APIS: "eth,net,web3,debug,admin"
  KUBE_CONFIG_PATH: "/opt/besu/shared/kube-config"
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: besu
  labels:
    app.kubernetes.io/name: besu
    app.kubernetes.io/release: "1.0.0"
spec:
  replicas: 1
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app.kubernetes.io/name: besu
        app.kubernetes.io/release: "1.0.0"
    spec:
      containers:
      - name: besu
        image: "hyperledger/besu:1.4.4-SNAPSHOT"
        imagePullPolicy: Always
        ports:
          - containerPort: 8545
          - containerPort: 30303
        envFrom:
        - configMapRef:
            name: besu-config
      restartPolicy: Always
status: {}

On GKE it may be necessary to give permissions to besu so that it can retrieve the list of services via the Kubernetes API

A simple solution is to call this command.

kubectl create clusterrolebinding myapp-view-binding --clusterrole=admin --serviceaccount=default:default

This command should only be used in DEV and not in production. In production we need a finer management of permissions using Kubernetes Role-based access control

If BESU does not have permissions (or if it does not detect the service) it will use the fallback mechanism by warning the user.
If the user does not want to use the detection he can call BESU with the --nat-method = NONE option

[AbdelStark]

Looks good to me.