gateway

In Baidu Encyclopedia, the definition of gateway is like this: Gateway is the “gateway” that connects one network to another network.Similarly, the application gateway is the gateway through which external traffic flows into the application in Rainbond.It can also be said to be a “gateway” for north-south traffic to flow from north to south.All components deployed to Rainbond need to pass through the application gateway if they need to be accessed externally.

gateway - 图1

The role of application gateway

Before introducing the role of the application gateway, we first need to mention Ingress.Ingress is one of the Kubernetes resource types that defines the specification of routing policies from outside the cluster to services within the cluster. Note that Kubernetes does not provide an implementation of these policy routes.

The role of the application gateway is to implement various policies defined in Ingress. In addition to HTTP and HTTPs routing, the application gateway also provides other rich functions. The currently supported functions are:

  • HTTP and HTTPs Policies
  • TCP/UDP policy
  • Pan-domain policy
  • Multiple load balancing algorithms
  • Advanced routing: access control based on access paths, request headers, cookies, and weights
  • Service and domain name access monitoring

Policy Definition

The strategy is mainly divided into two parts, routing rules and routing targets. The routing target can be every port of all components. The routing rules have the following categories according to different：.

  • HTTP policy According to the HTTP protocol specification, the routing conditions supported by the HTTP policy includedomain names request paths Cookie Header HTTPS, and the same routing conditions support the definition of different weight values.The open source version of the load balancing algorithm supports the round-robin algorithm, and the enterprise version supports the expansion of multiple load balancing algorithms.

  • TCP/UDP strategy According to the TCP/UDP protocol specification, the routing conditions supported by the TCP/UDP strategy includeIPandport, and the open source version of the load balancing algorithm supports the polling algorithm.