[BOUNTY-4] Add NAT Kubernetes Support

[matkt]

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

PR description

The goal of this work is to offer developers a consistent API for performing NAT tasks, and add support for Kubernetes NAT implementation when Besu is being run from a Kubernetes cluster.

• Properly detects when Besu is being run inside a Kubernetes cluster.

Besu will automatically detect that the client is in a kubernetes.

• Interacts with Kubernetes APIs, as needed, to determine external IP address and exposed ports.

Besu will automatically try to detect the external IP address and the exposed ports thanks to the sdk https://github.com/kubernetes-client/java under Apache 2.0

The configuration will be in the '/opt/besu/shared/kube-config' location

Sample of script in order to define the port mapping

---
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: 9000
    targetPort: 8545
  - name: "rlpx"
    port: 7777
    targetPort: 8888
  selector:
    app.kubernetes.io/name: besu
    app.kubernetes.io/release: "1.0.0"
  type: LoadBalancer

---
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:
      volumes:
        - name: task-pv-storage
          persistentVolumeClaim:
            claimName: task-pv-claim
      containers:
      - name: besu
        image: "hyperledger/besu:1.4.1-SNAPSHOT"
        imagePullPolicy: Never
        ports:
          - containerPort: 8545
        volumeMounts:
          - mountPath: "/opt/besu/shared"
            name: task-pv-storage
        envFrom:
        - configMapRef:
            name: besu-config
      restartPolicy: Always
status: {}

• Create persistent volume
  kubectl apply -f pv-volume.yml

• Claim volume
  kubectl apply -f pv-claim.yml

• Copy the kube config file in the mounted directory.

• Deploy Besu service.
  kubectl apply -f besu-service.yml -f besu-deployment.yml

[RatanRSur]

What happens if it would return the NatMethod for both of these? Do we want Docker to be returned even if Kubernetes would be detected?

[matkt]

The first method detected would be the one selected. In the order they are declared. However in that case Kubernetes would be detected. The detection method for docker and kubernetes are mutually exclusive.

[RatanRSur]

The detection method for docker and kubernetes are mutually exclusive.

I understand that only one would end up being selected but is it possible a misconfigured docker container inside a kubernetes "pod" (or whatever the term is haha), could succeed on the docker detector and not go on to the kubernetes detector? I ask because my intuition tells me that we should attempt to detect if we're in kubernetes first since it's the case that is a less general case.

[matkt]

The detection method for docker and kubernetes are mutually exclusive.
I understand that only one would end up being selected but is it possible a misconfigured docker container inside a kubernetes "pod" (or whatever the term is haha), could succeed on the docker detector and not go on to the kubernetes detector? I ask because my intuition tells me that we should attempt to detect if we're in kubernetes first since it's the case that is a less general case.

Ok I can create a new PR in order to change the order and put kubernetes detector first.

[AbdelStark]

Looks good to me.