Combine stdout/stderr (experimental)

Don't panic on error, keep alive and return 500.

watchdog/main.go

 package main
 
 import (
+	"bytes"
 	"io/ioutil"
 	"log"
 	"net/http"
@@ -20,18 +21,31 @@ func main() {
 
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method == "POST" {
+
 			process := os.Getenv("fprocess")
+
 			parts := strings.Split(process, " ")
+
 			targetCmd := exec.Command(parts[0], parts[1:]...)
 			writer, _ := targetCmd.StdinPipe()
+
 			res, _ := ioutil.ReadAll(r.Body)
+
 			writer.Write(res)
 			writer.Close()
+
 			out, err := targetCmd.Output()
+			targetCmd.CombinedOutput()
 			if err != nil {
-				panic(err)
+				log.Println(targetCmd, err)
+				w.WriteHeader(500)
+				response := bytes.NewBufferString(err.Error())
+				w.Write(response.Bytes())
+				return
 			}
+			w.WriteHeader(200)
 
+			// TODO: consider stdout to container as configurable via env-variable.
 			os.Stdout.Write(out)
 			w.Write(out)
 		}