support fetching config from http

common/platform/ctlcmd/ctlcmd.go

@@ -0,0 +1,67 @@
+package ctlcmd
+
+import (
+	"context"
+	"io"
+	"os"
+	"os/exec"
+
+	"v2ray.com/core/common/buf"
+	"v2ray.com/core/common/platform"
+	"v2ray.com/core/common/signal"
+)
+
+//go:generate go run $GOPATH/src/v2ray.com/core/common/errors/errorgen/main.go -pkg ctlcmd -path Command,Platform,CtlCmd
+
+func Run(args []string, input io.Reader) (buf.MultiBuffer, error) {
+	v2ctl := platform.GetToolLocation("v2ctl")
+	if _, err := os.Stat(v2ctl); err != nil {
+		return nil, err
+	}
+
+	errBuffer := &buf.MultiBuffer{}
+
+	cmd := exec.Command(v2ctl, args...)
+	cmd.Stderr = errBuffer
+	cmd.SysProcAttr = getSysProcAttr()
+	if input != nil {
+		cmd.Stdin = input
+	}
+
+	stdoutReader, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, err
+	}
+	defer stdoutReader.Close()
+
+	if err := cmd.Start(); err != nil {
+		return nil, err
+	}
+
+	var content buf.MultiBuffer
+	loadTask := signal.ExecuteAsync(func() error {
+		c, err := buf.ReadAllToMultiBuffer(stdoutReader)
+		if err != nil {
+			return err
+		}
+		content = c
+		return nil
+	})
+
+	waitTask := signal.ExecuteAsync(func() error {
+		if err := cmd.Wait(); err != nil {
+			msg := "failed to execute v2ctl"
+			if errBuffer.Len() > 0 {
+				msg += ": " + errBuffer.String()
+			}
+			return newError(msg).Base(err)
+		}
+		return nil
+	})
+
+	if err := signal.ErrorOrFinish2(context.Background(), loadTask, waitTask); err != nil {
+		return nil, err
+	}
+
+	return content, nil
+}