reqwest-lb

A crate for reqwest support load balancer, use the reqwest-middleware.

Overview

This crate provide a middleware LoadBalancerMiddleware, it implement reqwest-middleware::Middleware.

• dependencies

  [dependencies]
  
  reqwest = "0.12"
  
  reqwest-middleware = "0.3"
  
  reqwest-lb = "0.1"
  
  

• example

  use reqwest::{Client, Url};
  use reqwest_lb::LoadBalancerMiddleware;
  use reqwest_lb::SimpleLoadBalancer;
  use reqwest_lb::{LoadBalancerFactory, LoadBalancerPolicy};
  use reqwest_middleware::{ClientBuilder, ClientWithMiddleware};
  
  pub fn create<const N: usize>(
      ports: [u16; N],
      policy: LoadBalancerPolicy<Url>,
  ) -> ClientWithMiddleware {
      // create load balancer factory
      let mut factory = LoadBalancerFactory::default();
  
      // create url list
      let mut urls = Vec::with_capacity(N);
      for port in ports {
          urls.push(Url::parse(format!("http://127.0.0.1:{}", port).as_str()).unwrap());
      }
  
      // create load balancer
      let load_balancer = SimpleLoadBalancer::new(urls, policy);
  
      // register load balancer for the host: example-server
      factory.add("example-server", load_balancer);
  
      // create reqwest client
      let middleware = LoadBalancerMiddleware::new(factory);
      ClientBuilder::new(Client::builder().no_proxy().build().unwrap())
          .with(middleware)
          .build()
  }
  
  pub async fn run() {
      // use round robin policy
      let client = create([3001, 3002], LoadBalancerPolicy::RoundRobin);
      // http://127.0.0.1:3001
      let response = client.get("lb://example-server/").send().await.unwrap();
      // http://127.0.0.1:3002
      let response = client.get("lb://example-server/").send().await.unwrap();
  }
  
  

• load balancer policy

  • RoundRobin (default)
  • Random
  • First
  • Last
  • Weight

• discovery

  ...

License

This project is licensed under the Apache 2.0