Enable IPv6 for Pods in ACS Clusters with Dual-Stack Support - Container Compute Service

Pods in Alibaba Cloud Container Compute Service (ACS) clusters support both IPv4 and IPv6. Assign an IPv6 address to a pod by adding annotations to the pod metadata. Optionally, configure public Internet bandwidth for that address.

Background information

IPv4 addresses are widely used, but the limited IPv4 address space restricts the development of the Internet. IPv6 addresses resolve this address space issue and allow more types of devices to access the Internet. For more information, see What is an IPv6 gateway?.

Limitations

One address per pod: Each pod supports only one IPv6 address.
Resource specifications required: You can only assign IPv6 addresses to pods that have explicit vCPU and memory resource specifications.

Prerequisites

Before you begin, make sure you have:

An ACS cluster with IPv6 dual-stack enabled. See Create an ACS cluster

Annotations

Add annotations to the pod metadata to assign an IPv6 address and, optionally, configure Internet bandwidth for that address.

Annotation	Example value	Required	Description
`network.alibabacloud.com/enable-ipv6`	`"true"`	Yes	Assigns an IPv6 address to the pod.
`network.alibabacloud.com/ipv6-bandwidth-enable`	`"true"`	No	Enables public Internet access over IPv6 for the pod. Set to `"true"` if the pod needs to send or receive traffic over the public Internet using its IPv6 address.
`network.alibabacloud.com/ipv6-bandwidth`	`100M`	No	Sets the peak Internet bandwidth for the IPv6 address, in Mbit/s. Valid ranges depend on the IPv6 gateway billing method: pay-by-bandwidth allows 1–2,000 Mbit/s; pay-by-traffic allows 1–1,000 Mbit/s. If omitted when `ipv6-bandwidth-enable` is `"true"`, the bandwidth defaults to the maximum supported by the IPv6 gateway.

Important

Add annotations to the pod metadata section, not the top-level Deployment metadata. For a Deployment, place them under spec.template.metadata.annotations. Annotations only take effect when a pod is created — adding or modifying them on an existing pod has no effect.

Assign an IPv6 address to a pod

Create a file named nginx.yaml with the following content:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      name: nginx-test
      labels:
        app: nginx
      annotations:
        network.alibabacloud.com/enable-ipv6: "true"               # Assign an IPv6 address to the pod.
        network.alibabacloud.com/ipv6-bandwidth-enable: "true"     # Enable public Internet access over IPv6.
        network.alibabacloud.com/ipv6-bandwidth: 100M              # Set peak Internet bandwidth to 100 Mbit/s.
    spec:
      containers:
      - name: nginx
        image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest
        ports:
        - containerPort: 80

Deploy the Deployment:
```
kubectl apply -f nginx.yaml
```
Verify that an IPv6 address was assigned to the pod:
```
kubectl describe pod nginx-xxxxx-xxxxx | grep ipv6-address
```
The output shows the assigned IPv6 address in the network.alibabacloud.com/allocated-ipv6-address annotation:
```
network.alibabacloud.com/allocated-ipv6-address: 2408:4005:317:301:c870:xxxx:xxxx:xxxx
```
If the annotation does not appear, check that:
- The ACS cluster has IPv6 dual-stack enabled.
- The pod was created (not updated) with the network.alibabacloud.com/enable-ipv6: "true" annotation.