Namespace level Default EgressGateway

Introduction

Setting a default EgressGateway for a namespace simplifies the process of specifying the EgressGateway name when using EgressPolicy under the namespace. The priority of the namespace level default EgressGateway is higher than the cluster level default EgressGateway. In other words, when a namespace level default gateway is specified, the tenant's default settings will be used first. If the namespace does not have a default gateway set, the cluster's default settings will be used.

Requirements

EgressGateway component is installed.
An EgressGateway CR has been created.

Steps

Use the following command to specify the default EgressGateway name for the tenant:
```
kubectl label ns default spidernet.io/egressgateway-default=egressgateway
```

Use the following definition to create an EgressPolicy, ignoring the definition of the spec.egressGatewayName field:

apiVersion: egressgateway.spidernet.io/v1beta1
kind: EgressPolicy
metadata:
  name: mock-app
spec:
  appliedTo:
    podSelector:
      matchLabels:
        app: mock-app
  destSubnet:
    - 10.6.1.92/32

Run the following command again to confirm that the EgressPolicy has been set to the default EgressGateway:

$ kubectl get egresspolicies mock-app -o yaml
apiVersion: egressgateway.spidernet.io/v1beta1
kind: EgressPolicy
metadata:
  creationTimestamp: "2023-08-09T10:54:34Z"
  generation: 1
  name: mock-app
  namespace: default
  resourceVersion: "6233341"
  uid: 5692c5e6-a71b-41bd-a611-1106abd41ba3
spec:
  appliedTo:
    podSelector:
      matchLabels:
        app: mock-app
  destSubnet:
  - 10.6.1.92/32
  - fd00::92/128
  - 172.30.40.0/21
  egressGatewayName: egressgateway