agent: Fix script quoting on windows (#1875)

This patch fixes the quoting for executing scripts on windows
and splits the platform dependent code.

Fixes #1875

Author: mprokop

CHANGELOG.md

@@ -17,6 +17,7 @@ BUG FIXES:
 * agent: Clean up temporary files during disk write errors when persisting services and checks. [GH-3207]
 * agent: Fixed an issue where dns and client bind address templates were not being parsed via the go-sockaddr library. [GH-3322]
 * agent: Fixed status code on all KV store operations that fail due to an ACL issue. They now return a 403 status code, rather than a 404. [GH-2637]
+* agent: Fixed quoting issues in script health check on windows. [GH-1875]
 
 ## 0.9.0 (July 20, 2017)
 

agent/util.go

@@ -6,9 +6,7 @@ import (
 	"fmt"
 	"math"
 	"os"
-	"os/exec"
 	"os/user"
-	"runtime"
 	"strconv"
 	"time"
 
@@ -45,23 +43,6 @@ func aeScale(interval time.Duration, n int) time.Duration {
 	return time.Duration(multiplier) * interval
 }
 
-// ExecScript returns a command to execute a script
-func ExecScript(script string) (*exec.Cmd, error) {
-	var shell, flag string
-	if runtime.GOOS == "windows" {
-		shell = "cmd"
-		flag = "/C"
-	} else {
-		shell = "/bin/sh"
-		flag = "-c"
-	}
-	if other := os.Getenv("SHELL"); other != "" {
-		shell = other
-	}
-	cmd := exec.Command(shell, flag, script)
-	return cmd, nil
-}
-
 // decodeMsgPack is used to decode a MsgPack encoded object
 func decodeMsgPack(buf []byte, out interface{}) error {
 	return codec.NewDecoder(bytes.NewReader(buf), msgpackHandle).Decode(out)

agent/util_other.go

@@ -0,0 +1,18 @@
+// +build !windows
+
+package agent
+
+import (
+	"os"
+	"os/exec"
+)
+
+
+// ExecScript returns a command to execute a script
+func ExecScript(script string) (*exec.Cmd, error) {
+	shell := "/bin/sh"
+	if other := os.Getenv("SHELL"); other != "" {
+		shell = other
+	}
+	return exec.Command(shell, "-c", script), nil
+}

agent/util_windows.go

@@ -0,0 +1,24 @@
+// +build windows
+
+package agent
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+)
+
+// ExecScript returns a command to execute a script
+func ExecScript(script string) (*exec.Cmd, error) {
+	shell := "cmd"
+	if other := os.Getenv("SHELL"); other != "" {
+		shell = other
+	}
+	script = "\"" + script + "\"";
+	cmd := exec.Command(shell, "/C", script)
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		CmdLine: strings.Join(cmd.Args, " "),
+	}
+	return cmd, nil
+}