跳到主要内容

Network Options

RKE2 requires a CNI plugin to connect pods and services. The Canal CNI plugin is the default but all CNI plugins are supported. All CNI plugins get installed via a helm chart after the main components are up and running and can be customized by modifying the helm chart options.

Install a CNI plugin​

RKE2 integrates with four different CNI plugins: Canal, Cilium, Calico and Flannel. Note that only Calico and Flannel are options for RKE2 deployments with Windows nodes.

The next tabs inform how to deploy each CNI plugin and override the default options:

Canal means using Flannel for inter-node traffic and Calico for intra-node traffic and network policies. By default, it will use vxlan encapsulation to create an overlay network among nodes. Canal is deployed by default in RKE2 and thus nothing must be configured to activate it. To override the default Canal options you should create a HelmChartConfig resource. The HelmChartConfig resource must match the name and namespace of its corresponding HelmChart. For example to override the flannel interface, you can apply the following config:

# /var/lib/rancher/rke2/server/manifests/rke2-canal-config.yaml
---
apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: rke2-canal
  namespace: kube-system
spec:
  valuesContent: |-
    flannel:
      iface: "eth1"

Starting with RKE2 v1.23 it is possible to use flannel's wireguard backend for in-kernel WireGuard encapsulation and encryption (Users of kernels < 5.6 need to install a module). This can be achieved using the following config:

# /var/lib/rancher/rke2/server/manifests/rke2-canal-config.yaml
---
apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: rke2-canal
  namespace: kube-system
spec:
  valuesContent: |-
    flannel:
      backend: "wireguard"

After that, please restart the canal daemonset to use the newer config by executing: kubectl rollout restart ds rke2-canal -n kube-system

For more information about the full options of the Canal config please refer to the rke2-charts.

备注

Canal requires the iptables or xtables-nft package to be installed on the node.

注意

Canal is currently not supported on clusters with Windows nodes.

Please check Known issues and Limitations if you experience IP allocation problems

Dual-stack configuration​

IPv4/IPv6 dual-stack networking enables the allocation of both IPv4 and IPv6 addresses to Pods and Services. To configure RKE2 in dual-stack mode, in the control-plane nodes, you must set a valid IPv4/IPv6 dual-stack cidr for pods and services. To do so, use the flags --cluster-cidr and --service-cidr for example:

#/etc/rancher/rke2/config.yaml
cluster-cidr: "10.42.0.0/16,2001:cafe:42::/56"
service-cidr: "10.43.0.0/16,2001:cafe:43::/112"

Each CNI plugin may require a different configuration for dual-stack:

Canal automatically detects the RKE2 configuration for dual-stack and does not need any extra configuration. Dual-stack is currently not supported in the windows installations of RKE2.

IPv6 setup​

In case of IPv6 only configuration RKE2 needs to use localhost to access the liveness URL of the ETCD pod; check that your operating system configures /etc/hosts file correctly:

::1       localhost

Nodes Without a Hostname​

Some cloud providers, such as Linode, will create machines with "localhost" as the hostname and others may not have a hostname set at all. This can cause problems with domain name resolution. You can run RKE2 with the node-name parameter and this will pass the node name to resolve this issue.