moonstream/nodes/node_balancer/cmd/routes.go

84 wiersze
2.4 KiB
Go

/*
Handle routes for load balancer API.
*/
package cmd
import (
"encoding/json"
"fmt"
"log"
"net/http"
"strings"
configs "github.com/bugout-dev/moonstream/nodes/node_balancer/configs"
)
// pingRoute response with status of load balancer server itself
func pingRoute(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
response := PingResponse{Status: "ok"}
json.NewEncoder(w).Encode(response)
}
// lbHandler load balances the incoming requests to nodes
func lbHandler(w http.ResponseWriter, r *http.Request) {
attempts := GetAttemptsFromContext(r)
if attempts > configs.NB_CONNECTION_RETRIES {
log.Printf("Max attempts reached from %s %s, terminating\n", r.RemoteAddr, r.URL.Path)
http.Error(w, "Service not available", http.StatusServiceUnavailable)
return
}
var blockchain string
switch {
case strings.HasPrefix(r.URL.Path, "/nb/ethereum"):
blockchain = "ethereum"
case strings.HasPrefix(r.URL.Path, "/nb/polygon"):
blockchain = "polygon"
default:
http.Error(w, fmt.Sprintf("Unacceptable blockchain provided %s", blockchain), http.StatusBadRequest)
return
}
clientId := w.Header().Get(configs.MOONSTREAM_CLIENT_ID_HEADER)
if clientId == "" {
// TODO(kompotkot): After all internal crawlers and services start
// providing client id header, then replace to http.Error
clientId = "none"
}
// Chose one node
var node *Node
cpool, err := GetClientPool(blockchain)
if err != nil {
http.Error(w, fmt.Sprintf("Unacceptable blockchain provided %s", blockchain), http.StatusBadRequest)
return
}
node = cpool.GetClientNode(clientId)
if node == nil {
node = blockchainPool.GetNextNode(blockchain)
if node == nil {
http.Error(w, "There are no nodes available", http.StatusServiceUnavailable)
return
}
cpool.AddClientNode(clientId, node)
}
// Save origin path, to use in proxyErrorHandler if node will not response
r.Header.Add("X-Origin-Path", r.URL.Path)
switch {
case strings.HasPrefix(r.URL.Path, fmt.Sprintf("/nb/%s/ping", blockchain)):
r.URL.Path = "/ping"
node.StatusReverseProxy.ServeHTTP(w, r)
return
case strings.HasPrefix(r.URL.Path, fmt.Sprintf("/nb/%s/jsonrpc", blockchain)):
r.URL.Path = "/"
node.GethReverseProxy.ServeHTTP(w, r)
return
default:
http.Error(w, fmt.Sprintf("Unacceptable path for %s blockchain %s", blockchain, r.URL.Path), http.StatusBadRequest)
return
}
}