Add -returnOutput flag to return output of application back to DCS in case of successful execution

Author: wilriker

README.md

@@ -20,6 +20,8 @@ Usage of ./execonmcode:
         Code that will initiate execution of the command. This can be specified multiple times.
   -noFlush
         Do not flush the code channel before executing the associated command
+  -returnOutput
+        Return the output of the command back to DCS. Use with care. Cannot be combined with -execAsync.
   -socketPath string
         Path to socket (default "/var/run/dsf/dcs.sock")
   -trace

cmd/eom/execonmcode.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"log"
 	"os"
 	"strings"
@@ -12,7 +13,7 @@ import (
 )
 
 const (
-	version = "5.1.1"
+	version = "5.1.2"
 )
 
 func main() {
@@ -25,13 +26,14 @@ func main() {
 	flag.Var(&s.Commands, "command", "Command to execute. This can be specified multiple times.")
 	flag.BoolVar(&s.NoFlush, "noFlush", false, "Do not flush the code channel before executing the associated command")
 	flag.BoolVar(&s.ExecAsync, "execAsync", false, "Run command to execute async and return success to DCS immediately")
+	flag.BoolVar(&s.ReturnOutput, "returnOutput", false, "Return the output of the command back to DCS. Use with care. Cannot be combined with -execAsync.")
 	flag.BoolVar(&s.Debug, "debug", false, "Print debug output")
 	flag.BoolVar(&s.Trace, "trace", false, "Print underlying requests/responses")
-	version := flag.Bool("version", false, "Show version and exit")
+	printVersion := flag.Bool("version", false, "Show version and exit")
 	flag.Parse()
 
-	if *version {
-		log.Println(version)
+	if *printVersion {
+		fmt.Println(version)
 		os.Exit(0)
 	}
 
@@ -50,6 +52,10 @@ func main() {
 		log.Fatal("Unsupported InterceptionMode", s.InterceptionMode)
 	}
 
+	if s.ExecAsync && s.ReturnOutput {
+		log.Fatal("-execAsync and -returnOutput cannot be used together.")
+	}
+
 	e := execonmcode.NewExecutor(s)
 	err := e.Run()
 	if err != nil {

executor.go

@@ -18,14 +18,15 @@ const (
 )
 
 type Executor struct {
-	socketPath string
-	mode       initmessages.InterceptionMode
-	mCodes     map[int64]int
-	commands   Commands
-	execAsync  bool
-	flush      bool
-	debug      bool
-	trace      bool
+	socketPath   string
+	mode         initmessages.InterceptionMode
+	mCodes       map[int64]int
+	commands     Commands
+	execAsync    bool
+	returnOutput bool
+	flush        bool
+	debug        bool
+	trace        bool
 }
 
 func NewExecutor(s Settings) *Executor {
@@ -41,14 +42,15 @@ func NewExecutor(s Settings) *Executor {
 		}
 	}
 	return &Executor{
-		socketPath: s.SocketPath,
-		mode:       initmessages.InterceptionMode(s.InterceptionMode),
-		mCodes:     mc,
-		commands:   s.Commands,
-		execAsync:  s.ExecAsync,
-		flush:      !s.NoFlush,
-		debug:      s.Debug,
-		trace:      s.Trace,
+		socketPath:   s.SocketPath,
+		mode:         initmessages.InterceptionMode(s.InterceptionMode),
+		mCodes:       mc,
+		commands:     s.Commands,
+		execAsync:    s.ExecAsync,
+		returnOutput: s.ReturnOutput,
+		flush:        !s.NoFlush,
+		debug:        s.Debug,
+		trace:        s.Trace,
 	}
 }
 
@@ -109,7 +111,11 @@ func (e *Executor) Run() error {
 					if err != nil {
 						err = ic.ResolveCode(messages.Error, fmt.Sprintf("%s: %s", err.Error(), string(output)))
 					} else {
-						err = ic.ResolveCode(messages.Success, "")
+						msg := ""
+						if e.returnOutput {
+							msg = string(output)
+						}
+						err = ic.ResolveCode(messages.Success, msg)
 					}
 				}
 				if err != nil {

settings.go

@@ -7,6 +7,7 @@ type Settings struct {
 	Commands         Commands
 	NoFlush          bool
 	ExecAsync        bool
+	ReturnOutput     bool
 	Debug            bool
 	Trace            bool
 }