Kelp GUI: fix too many open files error (closes #292 and closes #385)…

… (#386)

* 1 - attempt to fix stream closing issues in kelpos.Blocking()

* 2 - only close manually created pipes, not Std* pipes

* 3 - the actual fix, Wait() after Read()

see: hashicorp/go-plugin#116 (comment)

* 4 - remove IPC server and components since that is causing an explosion of pipes/files and is also unused

closes #385

cmd/trade.go

@@ -20,7 +20,6 @@ import (
 	"github.com/stellar/kelp/database"
 	"github.com/stellar/kelp/model"
 	"github.com/stellar/kelp/plugins"
-	"github.com/stellar/kelp/query"
 	"github.com/stellar/kelp/support/logger"
 	"github.com/stellar/kelp/support/monitoring"
 	"github.com/stellar/kelp/support/networking"
@@ -71,7 +70,6 @@ type inputs struct {
 	stratConfigPath               *string
 	operationalBuffer             *float64
 	operationalBufferNonNativePct *float64
-	withIPC                       *bool
 	simMode                       *bool
 	logPrefix                     *string
 	fixedIterations               *uint64
@@ -128,7 +126,6 @@ func init() {
 	// long-only flags
 	options.operationalBuffer = tradeCmd.Flags().Float64("operationalBuffer", 20, "buffer of native XLM to maintain beyond minimum account balance requirement")
 	options.operationalBufferNonNativePct = tradeCmd.Flags().Float64("operationalBufferNonNativePct", 0.001, "buffer of non-native assets to maintain as a percentage (0.001 = 0.1%)")
-	options.withIPC = tradeCmd.Flags().Bool("with-ipc", false, "enable IPC communication when spawned as a child process from the GUI")
 	options.simMode = tradeCmd.Flags().Bool("sim", false, "simulate the bot's actions without placing any trades")
 	options.logPrefix = tradeCmd.Flags().StringP("log", "l", "", "log to a file (and stdout) with this prefix for the filename")
 	options.fixedIterations = tradeCmd.Flags().Uint64("iter", 0, "only run the bot for the first N iterations (defaults value 0 runs unboundedly)")
@@ -566,18 +563,6 @@ func runTradeCmd(options inputs) {
 		db,
 		threadTracker,
 	)
-	startQueryServer(
-		l,
-		*options.strategy,
-		strategy,
-		botConfig,
-		client,
-		sdex,
-		exchangeShim,
-		tradingPair,
-		threadTracker,
-		&options,
-	)
 	// --- end initialization of services ---
 
 	l.Info("Starting the trader bot...")
@@ -683,47 +668,6 @@ func startFillTracking(
 	}
 }
 
-func startQueryServer(
-	l logger.Logger,
-	strategyName string,
-	strategy api.Strategy,
-	botConfig trader.BotConfig,
-	client *horizonclient.Client,
-	sdex *plugins.SDEX,
-	exchangeShim api.ExchangeShim,
-	tradingPair *model.TradingPair,
-	threadTracker *multithreading.ThreadTracker,
-	options *inputs,
-) {
-	// only start query server (with IPC) if specifically instructed to so so from the command line.
-	// File descriptors in the IPC receiver will be invalid and will crash the bot if the other end of the pipe does not exist.
-	if !*options.withIPC {
-		return
-	}
-
-	qs := query.MakeServer(
-		l,
-		strategyName,
-		strategy,
-		botConfig,
-		client,
-		sdex,
-		exchangeShim,
-		tradingPair,
-	)
-
-	go func() {
-		defer logPanic(l, true)
-		e := qs.StartIPC()
-		if e != nil {
-			l.Info("")
-			l.Errorf("problem encountered while running the query server: %s", e)
-			// we want to delete all the offers and exit here because we don't want the bot to run if the query server isn't working
-			deleteAllOffersAndExit(l, botConfig, client, sdex, exchangeShim, threadTracker)
-		}
-	}()
-}
-
 func validateTrustlines(l logger.Logger, client *horizonclient.Client, botConfig *trader.BotConfig) {
 	if !botConfig.IsTradingSdex() {
 		l.Info("no need to validate trustlines because we're not using SDEX as the trading exchange")

gui/backend/get_bot_info.go

@@ -1,8 +1,6 @@
 package backend
 
 import (
-	"bufio"
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"log"
@@ -16,59 +14,40 @@ import (
 	"github.com/stellar/go/support/config"
 	"github.com/stellar/kelp/gui/model2"
 	"github.com/stellar/kelp/model"
-	"github.com/stellar/kelp/query"
 	"github.com/stellar/kelp/support/kelpos"
 	"github.com/stellar/kelp/support/utils"
 	"github.com/stellar/kelp/trader"
 )
 
 const buysell = "buysell"
 
+// botInfo is the response from the getBotInfo request
+type botInfo struct {
+	LastUpdated    string             `json:"last_updated"`
+	TradingAccount string             `json:"trading_account"`
+	Strategy       string             `json:"strategy"`
+	IsTestnet      bool               `json:"is_testnet"`
+	TradingPair    *model.TradingPair `json:"trading_pair"`
+	AssetBase      hProtocol.Asset    `json:"asset_base"`
+	AssetQuote     hProtocol.Asset    `json:"asset_quote"`
+	BalanceBase    float64            `json:"balance_base"`
+	BalanceQuote   float64            `json:"balance_quote"`
+	NumBids        int                `json:"num_bids"`
+	NumAsks        int                `json:"num_asks"`
+	SpreadValue    float64            `json:"spread_value"`
+	SpreadPercent  float64            `json:"spread_pct"`
+}
+
 func (s *APIServer) getBotInfo(w http.ResponseWriter, r *http.Request) {
 	botName, e := s.parseBotName(r)
 	if e != nil {
 		s.writeError(w, fmt.Sprintf("error parsing bot name in getBotInfo: %s\n", e))
 		return
 	}
 
-	// s.runGetBotInfoViaIPC(w, botName)
 	s.runGetBotInfoDirect(w, botName)
 }
 
-func (s *APIServer) runGetBotInfoViaIPC(w http.ResponseWriter, botName string) {
-	p, exists := s.kos.GetProcess(botName)
-	if !exists {
-		log.Printf("kelp bot process with name '%s' does not exist; processes available: %v\n", botName, s.kos.RegisteredProcesses())
-		w.WriteHeader(http.StatusNotFound)
-		w.Write([]byte("{}"))
-		return
-	}
-
-	log.Printf("getBotInfo is making IPC request for botName: %s\n", botName)
-	p.PipeIn.Write([]byte("getBotInfo\n"))
-	scanner := bufio.NewScanner(p.PipeOut)
-	output := ""
-	for scanner.Scan() {
-		text := scanner.Text()
-		if strings.Contains(text, utils.IPCBoundary) {
-			break
-		}
-		output += text
-	}
-	var buf bytes.Buffer
-	e := json.Indent(&buf, []byte(output), "", "  ")
-	if e != nil {
-		log.Printf("cannot indent json response (error=%s), json_response: %s\n", e, output)
-		w.WriteHeader(http.StatusInternalServerError)
-		w.Write([]byte("{}"))
-		return
-	}
-	log.Printf("getBotInfo returned IPC response for botName '%s': %s\n", botName, buf.String())
-
-	w.WriteHeader(http.StatusOK)
-	w.Write(buf.Bytes())
-}
-
 func (s *APIServer) runGetBotInfoDirect(w http.ResponseWriter, botName string) {
 	log.Printf("getBotInfo is invoking logic directly for botName: %s\n", botName)
 
@@ -171,7 +150,7 @@ func (s *APIServer) runGetBotInfoDirect(w http.ResponseWriter, botName string) {
 		spreadPct = spread / midPrice
 	}
 
-	bi := query.BotInfo{
+	bi := botInfo{
 		LastUpdated:    time.Now().UTC().Format("1/_2/2006 15:04:05 MST"),
 		TradingAccount: account.AccountID,
 		Strategy:       buysell,
@@ -189,7 +168,7 @@ func (s *APIServer) runGetBotInfoDirect(w http.ResponseWriter, botName string) {
 
 	marshalledJson, e := json.MarshalIndent(bi, "", "  ")
 	if e != nil {
-		log.Printf("cannot marshall to json response (error=%s), BotInfo: %+v\n", e, bi)
+		log.Printf("cannot marshall to json response (error=%s), botInfo: %+v\n", e, bi)
 		w.WriteHeader(http.StatusInternalServerError)
 		w.Write([]byte("{}"))
 		return