kompose/examples/web/main.go

134 lines
3.6 KiB
Go

package main
import (
"encoding/json"
"net/http"
"os"
"strings"
"github.com/codegangsta/negroni"
"github.com/gorilla/mux"
"github.com/xyproto/simpleredis/v2"
)
var (
leaderPool *simpleredis.ConnectionPool
replicaPools []*simpleredis.ConnectionPool
)
func ListRangeHandler(rw http.ResponseWriter, req *http.Request) {
key := mux.Vars(req)["key"]
var members []string
var err error
for _, replicaPool := range replicaPools {
list := simpleredis.NewList(replicaPool, key)
members, err = list.GetAll()
if err == nil {
break // Found a replica with data, exit loop
}
}
if err != nil {
http.Error(rw, "Failed to retrieve data from replicas", http.StatusInternalServerError)
return
}
membersJSON, err := json.MarshalIndent(members, "", " ")
if err != nil {
http.Error(rw, "Failed to marshal JSON", http.StatusInternalServerError)
return
}
rw.Write(membersJSON)
}
func ListPushHandler(rw http.ResponseWriter, req *http.Request) {
key := mux.Vars(req)["key"]
value := mux.Vars(req)["value"]
list := simpleredis.NewList(leaderPool, key)
HandleError(nil, list.Add(value))
ListRangeHandler(rw, req)
}
func InfoHandler(rw http.ResponseWriter, req *http.Request) {
info := HandleError(leaderPool.Get(0).Do("INFO")).([]byte)
rw.Write(info)
}
func EnvHandler(rw http.ResponseWriter, req *http.Request) {
environment := make(map[string]string)
for _, item := range os.Environ() {
splits := strings.Split(item, "=")
key := splits[0]
val := strings.Join(splits[1:], "=")
environment[key] = val
}
envJSON := HandleError(json.MarshalIndent(environment, "", " ")).([]byte)
rw.Write(envJSON)
}
func HandleError(result interface{}, err error) (r interface{}) {
if err != nil {
panic(err)
}
return result
}
func getReplicaPool() *simpleredis.ConnectionPool {
// Use the first replica as the primary replica for read operations
return replicaPools[0]
}
func main() {
// Read the Redis replica addresses from an environment variable
replicaAddresses := os.Getenv("REDIS_REPLICAS")
if replicaAddresses == "" {
// Use default values if not set
replicaAddresses = "redis-replica"
}
// Read the Redis port number from an environment variable
redisPort := os.Getenv("REDIS_PORT")
if redisPort == "" {
// Use default port if not set
redisPort = "6379"
}
// Read the Redis leader address from an environment variable
redisLeaderAddress := os.Getenv("REDIS_LEADER")
if redisLeaderAddress == "" {
// Use default leader address if not set
redisLeaderAddress = "redis-leader"
}
// Read the server port number from an environment variable
serverPort := os.Getenv("SERVER_PORT")
if serverPort == "" {
// Use default port if not set
serverPort = "8080"
}
// Construct the Redis leader and replica addresses
leaderAddress := redisLeaderAddress + ":" + redisPort
replicaAddressesArr := strings.Split(replicaAddresses, ",")
replicaPools = make([]*simpleredis.ConnectionPool, len(replicaAddressesArr))
for i, addr := range replicaAddressesArr {
replicaPools[i] = simpleredis.NewConnectionPoolHost(addr + ":" + redisPort)
defer replicaPools[i].Close()
}
// Create a connection pool for the leader using the constructed address
leaderPool = simpleredis.NewConnectionPoolHost(leaderAddress)
defer leaderPool.Close()
r := mux.NewRouter()
r.Path("/lrange/{key}").Methods("GET").HandlerFunc(ListRangeHandler)
r.Path("/rpush/{key}/{value}").Methods("GET").HandlerFunc(ListPushHandler)
r.Path("/info").Methods("GET").HandlerFunc(InfoHandler)
r.Path("/env").Methods("GET").HandlerFunc(EnvHandler)
n := negroni.Classic()
n.UseHandler(r)
n.Run(":" + serverPort)
}