EdgeMesh

Introduction

EdgeMesh, as the data plane component of the KubeEdge cluster, provides simple service discovery and traffic proxy functions for applications, thereby shielding the complex network structure in edge scenarios.

Background

KubeEdge is build based on Kubernetes, extending cloud-native containerized application orchestration capabilities to the edge. However, at the scenario of edge computer, the network topology is more complex. Edge nodes in different areas are often not interconnected, and the inter-communication of traffic between applications is the primary requirement of the business. For this scenairo, EdgeMesh offers a solution.

Why EdgeMesh?

EdgeMesh satisfies the new requirements in edge scenarios (e.g., limited edge resources, unstable edge cloud network, complex network structure, etc.), that is, high availability, high reliability, and extreme lightweight:

  • High availability
    • Use the capabilities provided by LibP2P to connect the network between edge nodes
    • Divide the communication between edge nodes into intra-LAN and cross-LAN
      • Intra-LAN communication: direct access
      • Cross-LAN communication: when the hole punching is successful, a connection channel is established between the Agents, otherwise it is forwarded through the Server relay
  • High reliability (offline scenario)
    • Both control plane and data plane traffic are delivered through the edge cloud channel
    • EdgeMesh internally implements a lightweight DNS server, thus no longer accessing the cloud CoreDNS
  • Extreme lightweight
    • Each node has one and only one Agent, which saves edge resources

User value

  • Enable users to have the ability to access edge-to-edge/edge-to-cloud/cloud-to-edge applications across different LANs
  • Compared to the mechanism of CoreDNS + Kube-Proxy + CNI service discovery, users only need to simply deploy an Agent to finish their goals

Key Features

Feature Sub-Feature Realization Degree
Service Discovery /
Traffic Governance HTTP
TCP
Websocket
HTTPS
Load Balance Random
Round Robin
Session Persistence
Edge Gateway External Access
Multi-NIC Monitoring
Cross-Subnet Communication Cross-Cloud Communication
Cross-LAN E2E Communication
Edge CNI Cross-Subnet Pod Communication +

Noting:

  • Features supported by the EdgeMesh version
  • + Features not available in the EdgeMesh version, but will be supported in subsequent versions
  • - Features not available in the EdgeMesh version, or deprecated features

Architecture

image

The above figure shows a brief overview of the EdgeMesh architecture, EdgeMesh contains EdgeMesh-Server and EdgeMesh-Agent.

The core components of EdgeMesh-Server include:

  • Tunnel-Server: Based on LibP2P, establish a connection with EdgeMesh-Agent to provide relay capability and hole punching capability

The core components of EdgeMesh-Agent include:

  • Proxier: Responsible for configuring the kernel's iptables rules, and intercepting requests to the EdgeMesh process
  • DNS: Built-in DNS resolver, which resolves the DNS request in the node into a service cluster IP
  • Traffic: A traffic forwarding module based on the Go-Chassis framework, which is responsible for forwarding traffic between applications
  • Controller: Obtains metadata (e.g., Service, Endpoints, Pod, etc.) through the Local APIServer capability on the edge side of KubeEdge
  • Tunnel-Agent: Based on LibP2P, using relay and hole punching to provide the ability of communicating across subnets

Guides

Prerequisites

Before using EdgeMesh, you need to understand the following prerequisites at first:

  • while using DestinationRule, the name of the DestinationRule must be equal to the name of the corresponding Service. EdgeMesh will determine the DestinationRule in the same namespace according to the name of the Service
  • Service ports must be named. The key/value pairs of port name must have the following syntax: name: <protocol>[-<suffix>]

Documents

Documentation is located on netlify.com. These documents can help you understand EdgeMesh better.

Installation

Follow the EdgeMesh installation document to install EdgeMesh.

Examples

Example1: HTTP traffic forwarding

Example2: TCP traffic forwarding

Example3: Websocket traffic forwarding

Example4: Load Balance

Example5: Cross-edge-cloud communication

Contact

If you need support, start with the 'Operation Guidance', and then follow the process that we've outlined

If you have any question, please contact us through the recommended information on KubeEdge

GitHub

https://github.com/kubeedge/edgemesh