update runtime to function

runtime/process/os/os.go

@@ -19,10 +19,11 @@ func (p *Process) Exec(exe *process.Executable) error {
 }
 
 func (p *Process) Fork(exe *process.Executable) (*process.PID, error) {
-	cmd := exec.Command(exe.Binary.Path)
-	if err := cmd.Start(); err != nil {
-		return nil, err
-	}
+	// create command
+	cmd := exec.Command(exe.Binary.Path, exe.Args...)
+	// set env vars
+	cmd.Env = append(cmd.Env, exe.Env...)
+
 	in, err := cmd.StdinPipe()
 	if err != nil {
 		return nil, err
@@ -36,6 +37,11 @@ func (p *Process) Fork(exe *process.Executable) (*process.PID, error) {
 		return nil, err
 	}
 
+	// start the process
+	if err := cmd.Start(); err != nil {
+		return nil, err
+	}
+
 	return &process.PID{
 		ID:     fmt.Sprintf("%d", cmd.Process.Pid),
 		Input:  in,

runtime/process/process.go

@@ -22,6 +22,10 @@ type Process interface {
 type Executable struct {
 	// The executable binary
 	Binary *packager.Binary
+	// The env variables
+	Env []string
+	// Args to pass
+	Args []string
 }
 
 // PID is the running process