A small loadbalancer API written in Go (Using Pat and Redigo)

loadbalancer.go

package main

import (
  "io"
  "fmt"
  "time"
  "net/http"
  "encoding/json"
  "github.com/bmizerany/pat"
  "github.com/garyburd/redigo/redis"
)

type LoadbalancerResponse struct {
  Redirect string `json:"redirect"`
  Timestamp int64 `json:"timestamp"`
}

func LoadbalancerServer(w http.ResponseWriter, req *http.Request) {
  // Connect to Redis
  c, err := redis.Dial("tcp", ":6379")

  if err != nil {
    fmt.Println("Error:", err)
  }

  defer c.Close()
  redirect_ip, err := redis.String(c.Do("GET", "redirect_ip"))

  if err != nil {
    fmt.Println("Error:", err)
  }

  // Populate the loadbalancer response struct
  response := LoadbalancerResponse{
    Redirect: redirect_ip,
    Timestamp: time.Now().Unix(),
  }

  // Marshal the JSON
  json, err := json.Marshal(response)

  if err != nil {
    fmt.Println("Error:", err)
  }

  // Return the JSON to the client
  io.WriteString(w, string(json))
}

func main() {
  m := pat.New()
  m.Get("/loadbalancer.json", http.HandlerFunc(LoadbalancerServer))

  http.Handle("/", m)
  http.ListenAndServe(":12345", nil)
}

I’m just playing around here… probably doing a lot of mistakes :)

The initial idea for this API is outlined in this article: http://c7.se/tiny-api-with-nginx/