From 1158ac4760bb6a08bf8539bfdb2c853ba9069ebc Mon Sep 17 00:00:00 2001
From: Barak Michener <me@barakmich.com>
Date: Fri, 30 Mar 2018 11:39:11 -0700
Subject: [PATCH] first cross-websocket ls

---
 client/connect.go |  91 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs.go             |  14 ++++++++
 fs/local.go       | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 206 insertions(+)
 create mode 100644 client/connect.go
 create mode 100644 fs.go
 create mode 100644 fs/local.go

diff --git a/client/connect.go b/client/connect.go
new file mode 100644
index 0000000..1f43c48
--- /dev/null
+++ b/client/connect.go
@@ -0,0 +1,91 @@
+package client
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"os/signal"
+	"time"
+
+	"github.com/barakmich/kubelwagen"
+	"github.com/barakmich/kubelwagen/fs"
+	"github.com/gorilla/websocket"
+	"github.com/sirupsen/logrus"
+)
+
+func Connect(addr string, dir string) {
+	closer := make(chan bool)
+
+	signalChan := make(chan os.Signal, 1)
+	signal.Notify(signalChan, os.Interrupt)
+
+	go func() {
+		for range signalChan {
+			fmt.Println("\nReceived an interrupt, disconnecting...")
+			close(closer)
+		}
+	}()
+
+	handler := fs.NewLocalFs(dir)
+	c := &client{
+		handler: handler,
+		closer:  closer,
+	}
+
+	err := c.DialAndServe(addr)
+	if err != nil {
+		logrus.Fatalf("Error dialing %s: %s\n", addr, err)
+	}
+	<-closer
+	time.Sleep(500 * time.Millisecond)
+}
+
+type client struct {
+	handler kubelwagen.FS
+	closer  chan bool
+	txchan  chan *kubelwagen.Response
+	conn    *websocket.Conn
+}
+
+func (c *client) DialAndServe(addr string) error {
+	var err error
+	c.txchan = make(chan *kubelwagen.Response, 20)
+	u := url.URL{Scheme: "ws", Host: addr, Path: "/"}
+	logrus.Printf("connecting to %s", u.String())
+
+	c.conn, _, err = websocket.DefaultDialer.Dial(u.String(), nil)
+	if err != nil {
+		return err
+	}
+	defer c.conn.Close()
+	go c.tx()
+	go c.rx()
+	<-c.closer
+	return nil
+}
+
+func (c *client) tx() {
+	for x := range c.txchan {
+		err := c.conn.WriteJSON(x)
+		if err != nil {
+			logrus.Errorf("tx error: %s\n", err)
+		}
+	}
+}
+
+func (c *client) rx() {
+	defer close(c.closer)
+	defer close(c.txchan)
+	for {
+		req := &kubelwagen.Request{}
+		err := c.conn.ReadJSON(req)
+		if err != nil {
+			logrus.Errorf("rx error: %s\n", err)
+			return
+		}
+		go func(req *kubelwagen.Request) {
+			resp := c.handler.Handle(req)
+			c.txchan <- resp
+		}(req)
+	}
+}
diff --git a/fs.go b/fs.go
new file mode 100644
index 0000000..6c8a9e2
--- /dev/null
+++ b/fs.go
@@ -0,0 +1,14 @@
+package kubelwagen
+
+import "github.com/hanwen/go-fuse/fuse"
+
+type FS interface {
+	Handle(req *Request) *Response
+}
+
+func ErrorResp(r *Request, err error) *Response {
+	return &Response{
+		ID:   r.ID,
+		Code: fuse.ToStatus(err),
+	}
+}
diff --git a/fs/local.go b/fs/local.go
new file mode 100644
index 0000000..3cbf76b
--- /dev/null
+++ b/fs/local.go
@@ -0,0 +1,101 @@
+package fs
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/barakmich/kubelwagen"
+	"github.com/hanwen/go-fuse/fuse"
+	"github.com/sirupsen/logrus"
+)
+
+type LocalFs struct {
+	base string
+	open map[int]*os.File
+}
+
+func NewLocalFs(path string) *LocalFs {
+	return &LocalFs{
+		base: path,
+		open: make(map[int]*os.File),
+	}
+}
+
+func (fs *LocalFs) Handle(r *kubelwagen.Request) *kubelwagen.Response {
+	switch r.Method {
+	case kubelwagen.MethodOpenDir:
+		return fs.openDir(r)
+	case kubelwagen.MethodGetAttr:
+		return fs.getAttr(r)
+	}
+	return &kubelwagen.Response{
+		ID:   r.ID,
+		Code: fuse.ENOSYS,
+	}
+}
+
+func (fs *LocalFs) getPath(r *kubelwagen.Request) string {
+	return filepath.Join(fs.base, r.Path)
+}
+
+func (fs *LocalFs) openDir(r *kubelwagen.Request) *kubelwagen.Response {
+	out := &kubelwagen.Response{
+		ID:   r.ID,
+		Code: fuse.OK,
+	}
+	// returns dirents and status
+
+	f, err := os.Open(fs.getPath(r))
+	if err != nil {
+		logrus.Errorf("LocalFS openDir (%s): %s\n", r.Path, err)
+		return kubelwagen.ErrorResp(r, err)
+	}
+	want := 100
+	output := make([]fuse.DirEntry, 0, want)
+	for {
+		infos, err := f.Readdir(want)
+		for i := range infos {
+			// workaround for https://code.google.com/p/go/issues/detail?id=5960
+			if infos[i] == nil {
+				continue
+			}
+			n := infos[i].Name()
+			d := fuse.DirEntry{
+				Name: n,
+			}
+			if s := fuse.ToStatT(infos[i]); s != nil {
+				d.Mode = uint32(s.Mode)
+				d.Ino = s.Ino
+			} else {
+				logrus.Printf("ReadDir entry %q for %q has no stat info", n, r.Path)
+			}
+			output = append(output, d)
+		}
+		if len(infos) < want || err == io.EOF {
+			break
+		}
+		if err != nil {
+			logrus.Errorln("Readdir() returned err:", err)
+			break
+		}
+	}
+	f.Close()
+
+	out.Dirents = output
+	return out
+}
+
+func (fs *LocalFs) getAttr(r *kubelwagen.Request) *kubelwagen.Response {
+	out := &kubelwagen.Response{
+		ID:   r.ID,
+		Code: fuse.OK,
+	}
+	fi, err := os.Stat(fs.getPath(r))
+	if err != nil {
+		logrus.Errorf("LocalFS getAttr (%s): %s\n", r.Path, err)
+		return kubelwagen.ErrorResp(r, err)
+	}
+	out.Stat = fuse.ToAttr(fi)
+	return out
+}