use-readfull-in-worker (#198)

* prevent potential issues when reading less bytes than expected

Author: ChristopherHX

main.go

@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 	"os/signal"
@@ -386,12 +387,12 @@ func main() {
 				defer cancelExec()
 				buf := make([]byte, 4)
 				for {
-					os.Stdin.Read(buf)
+					io.ReadFull(os.Stdin, buf)
 					messageType := binary.BigEndian.Uint32(buf)
-					os.Stdin.Read(buf)
+					io.ReadFull(os.Stdin, buf)
 					messageLength := binary.BigEndian.Uint32(buf)
 					src := make([]byte, messageLength)
-					os.Stdin.Read(src)
+					io.ReadFull(os.Stdin, src)
 					switch messageType {
 					case 1:
 						jobreq := &protocol.AgentJobRequestMessage{}