misc: fuse fs for the stats segment

This extra allows to mount a FUSE filesystem reflecting
the state of the stats segment.

Type: feature

Signed-off-by: Arthur de Kerhor <arthurdekerhor@gmail.com>
Change-Id: I692f9ca5a65c1123b3cf28c761455eec36049791

1 files changed, 91 insertions, 0 deletions

diff --git a/extras/vpp_stats_fs/cmd.go b/extras/vpp_stats_fs/cmd.go
new file mode 100644
index 00000000000..826b011b00d
--- /dev/null
+++ b/extras/vpp_stats_fs/cmd.go
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2021 Cisco Systems and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Copyright 2016 the Go-FUSE Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+// This file is the main program driver to mount the stats segment filesystem.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"os/signal"
+	"runtime"
+	"strings"
+	"syscall"
+
+	"git.fd.io/govpp.git/adapter/statsclient"
+	"git.fd.io/govpp.git/core"
+	"github.com/hanwen/go-fuse/v2/fs"
+)
+
+func main() {
+	statsSocket := flag.String("socket", statsclient.DefaultSocketName, "Path to VPP stats socket")
+	debug := flag.Bool("debug", false, "print debugging messages.")
+	flag.Parse()
+	if flag.NArg() < 1 {
+		fmt.Fprintf(os.Stderr, "usage: %s MOUNTPOINT\n", os.Args[0])
+		os.Exit(2)
+	}
+	//Conection to the stat segment socket.
+	sc := statsclient.NewStatsClient(*statsSocket)
+	fmt.Printf("Waiting for the VPP socket to be available. Be sure a VPP instance is running.\n")
+	c, err := core.ConnectStats(sc)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to connect to the stats socket: %v\n", err)
+		os.Exit(1)
+	}
+	defer c.Disconnect()
+	fmt.Printf("Connected to the socket\n")
+	//Creating the filesystem instance
+	root, err := NewStatsFileSystem(sc)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "NewStatsFileSystem failed: %v\n", err)
+		os.Exit(1)
+	}
+
+	//Mounting the filesystem.
+	opts := &fs.Options{}
+	opts.Debug = *debug
+	opts.AllowOther = true
+	server, err := fs.Mount(flag.Arg(0), root, opts)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Mount fail: %v\n", err)
+		os.Exit(1)
+	}
+
+	sigs := make(chan os.Signal)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+
+	fmt.Printf("Successfully mounted the file system in directory: %s\n", flag.Arg(0))
+	runtime.GC()
+
+	for {
+		go server.Wait()
+
+		<-sigs
+		fmt.Println("Unmounting...")
+		err := server.Unmount()
+		if err == nil || !strings.Contains(err.Error(), "Device or resource busy") {
+			break
+		}
+		fmt.Fprintf(os.Stderr, "Unmount fail: %v\n", err)
+	}
+}