raven-controlplane

Introduction

Edge node pools in a Container Service for Kubernetes (ACK) cluster allow you to manage on-premises data centers and edge devices over the public internet in a cloud-native manner. However, these on-premises environments and the cloud VPCs exist in separate network planes, which prevents direct communication between nodes. This separation can cause node IP address conflicts and complicates centralized monitoring and operations of edge resources by cloud components such as the APIServer, MetricsServer, and Prometheus.

To solve these issues, ACK provides the Raven component. Raven is a cloud-to-edge network tunnel component designed for edge computing scenarios. It resolves connectivity issues for edge nodes connecting to a cluster over the public internet and provides a stable and secure underlying network channel. Raven consists of a control plane component, raven-controlplane, and a data plane component, raven-agent-ds.

• raven-controlplane:

  • Configures traffic forwarding paths: It divides nodes into multiple network domains. The cluster control plane and all ECS nodes are in one network domain, and all nodes within each edge node pool are in their own network domain. It then selects multiple nodes in each domain to act as gateway nodes. When the cluster control plane sends a request to an edge node pool, or when a pod on an ECS node communicates with a pod in an edge node pool, traffic routes through the gateway nodes in their respective network domains. In edge node pools where nodes cannot communicate with each other, it selects no gateway node. Instead, each edge node communicates directly with the ECS gateway nodes.

  • Creates resources: It creates and manages the cloud resources required by Raven, such as CLB instances.

• raven-agent-ds: It is deployed as a DaemonSet on all nodes in the cluster. It runs in host network mode (hostNetwork) and is responsible for building encrypted tunnels between gateway nodes and forwarding traffic.

Billing

To build encrypted tunnels, the Raven component creates a pay-as-you-go public CLB instance, which is subject to fees based on CLB billing rules.

Usage notes

• This component is supported only on ACK managed clusters that run v1.33 or later.

• The ACK managed cluster must have at least one available ECS node.

Change history