Stability improvements

- Use stat Ino and Dev to determine when the mount is in place. - Let Create actually mount (so that it fails if it can't). - Add server polling so that peer drops are detected. Signed-off-by: Thomas Hallgren <[email protected]>
telepresenceio · Feb 25, 2024 · bdc394e · bdc394e
1 parent baa8a10
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diff --git a/README.md b/README.md
@@ -32,7 +32,8 @@ $ docker plugin install datawire/telemount:arm64 --alias telemount
 Create an intercept. Use `--local-mount-port 1234` to set up a bridge instead of mounting, and `--detailed-ouput --output yaml` so that
 the command outputs the environment in a readable form:
 ```console
-$ telepresence intercept --local-mount-port 1234  --port 8080 --http-header who=me --detailed-output --output yaml echo-easy
+$ telepresence connect
+$ telepresence intercept --local-mount-port 1234  --port 8080 --detailed-output --output yaml echo-easy
 ...
     TELEPRESENCE_CONTAINER: echo-easy
     TELEPRESENCE_MOUNTS: /var/run/secrets/kubernetes.io
@@ -51,6 +52,21 @@ namespace
 token
 ```
 
+## Debugging
+
+Start by building the plugin for debugging. This command both builds and enables the plugin:
+```console
+$ make debug
+```
+
+Figure out the ID of the plugin:
+```console
+$ PLUGIN_ID=`docker plugin inspect -f='{{json .Id}}' datawire/telemount:amd64 | xargs`
+```
+and start viewing what it prints on stderr. All logging goes to stderr:
+```
+$ sudo cat /run/docker/plugins/$PLUGIN_ID/$PLUGIN_ID-stderr
+```
 ## Credits
 To the [Rclone project](https://github.com/rclone/rclone) project and [PR 5668](https://github.com/rclone/rclone/pull/5668)
 specifically for showing a good way to create multi-arch plugins.

diff --git a/go.mod b/go.mod
@@ -2,13 +2,15 @@ module github.com/datawire/docker-volume-telemount
 
 go 1.21
 
-require github.com/docker/go-plugins-helpers v0.0.0-20211224144127-6eecb7beb651
+require (
+	github.com/docker/go-plugins-helpers v0.0.0-20211224144127-6eecb7beb651
+	golang.org/x/sys v0.17.0
+)
 
 require (
 	github.com/Microsoft/go-winio v0.6.1 // indirect
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf // indirect
 	github.com/docker/go-connections v0.5.0 // indirect
-	golang.org/x/mod v0.14.0 // indirect
-	golang.org/x/sys v0.16.0 // indirect
-	golang.org/x/tools v0.17.0 // indirect
+	golang.org/x/mod v0.15.0 // indirect
+	golang.org/x/tools v0.18.0 // indirect
 )
diff --git a/go.sum b/go.sum
@@ -6,11 +6,11 @@ github.com/docker/go-connections v0.5.0 h1:USnMq7hx7gwdVZq1L49hLXaFtUdTADjXGp+uj
 github.com/docker/go-connections v0.5.0/go.mod h1:ov60Kzw0kKElRwhNs9UlUHAE/F9Fe6GLaXnqyDdmEXc=
 github.com/docker/go-plugins-helpers v0.0.0-20211224144127-6eecb7beb651 h1:YcvzLmdrP/b8kLAGJ8GT7bdncgCAiWxJZIlt84D+RJg=
 github.com/docker/go-plugins-helpers v0.0.0-20211224144127-6eecb7beb651/go.mod h1:LFyLie6XcDbyKGeVK6bHe+9aJTYCxWLBg5IrJZOaXKA=
-golang.org/x/mod v0.14.0 h1:dGoOF9QVLYng8IHTm7BAyWqCqSheQ5pYWGhzW00YJr0=
-golang.org/x/mod v0.14.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/mod v0.15.0 h1:SernR4v+D55NyBH2QiEQrlBAnj1ECL6AGrA5+dPaMY8=
+golang.org/x/mod v0.15.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
 golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.16.0 h1:xWw16ngr6ZMtmxDyKyIgsE93KNKz5HKmMa3b8ALHidU=
-golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/tools v0.17.0 h1:FvmRgNOcs3kOa+T20R1uhfP9F6HgG2mfxDv1vrx1Htc=
-golang.org/x/tools v0.17.0/go.mod h1:xsh6VxdV005rRVaS6SSAf9oiAqljS7UZUacMZ8Bnsps=
+golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
+golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/tools v0.18.0 h1:k8NLag8AGHnn+PHbl7g43CtqZAwG60vZkLqgyZgIHgQ=
+golang.org/x/tools v0.18.0/go.mod h1:GL7B4CwcLLeo59yx/9UWWuNOW1n3VZ4f5axWfML7Lcg=
diff --git a/pkg/log/log.go b/pkg/log/log.go
@@ -49,11 +49,11 @@ func Fatal(v any) {
 }
 
 func Info(v any) {
-	_, _ = fmt.Fprintln(os.Stdout, v)
+	_, _ = fmt.Fprintln(os.Stderr, v)
 }
 
 func Infof(format string, args ...any) {
-	fprintfln(os.Stdout, format, args...)
+	fprintfln(os.Stderr, format, args...)
 }
 
 func Debug(v any) {

diff --git a/pkg/sftp/driver.go b/pkg/sftp/driver.go
@@ -17,7 +17,7 @@ import (
 
 type driver struct {
 	// All access to the driver is synchronized using this lock
-	sync.RWMutex
+	lock         sync.RWMutex
 	volumePath   string
 	remoteMounts map[string]*mount
 }
@@ -86,9 +86,13 @@ func (d *driver) Create(r *volume.CreateRequest) (err error) {
 	} else {
 		dir = filepath.Join(container, strings.TrimPrefix(dir, "/"))
 	}
-	d.Lock()
-	d.getRemoteMount(host, port).addVolume(r.Name, dir)
-	d.Unlock()
+	d.lock.Lock()
+	defer d.lock.Unlock()
+	m, err := d.getRemoteMount(host, port)
+	if err != nil {
+		return err
+	}
+	m.addVolume(r.Name, dir)
 	return nil
 }
 
@@ -97,8 +101,8 @@ func (d *driver) Remove(r *volume.RemoveRequest) (err error) {
 	defer func() {
 		logResponse(err, "Remove %s return", r.Name)
 	}()
-	d.Lock()
-	defer d.Unlock()
+	d.lock.Lock()
+	defer d.lock.Unlock()
 
 	var v *volumeDir
 	if v, err = d.getVolume(r.Name); err != nil {
@@ -118,8 +122,8 @@ func (d *driver) Mount(r *volume.MountRequest) (mr *volume.MountResponse, err er
 	defer func() {
 		logResponse(err, "Mount %s return %s", r.Name, mr.Mountpoint)
 	}()
-	d.Lock()
-	defer d.Unlock()
+	d.lock.Lock()
+	defer d.lock.Unlock()
 
 	var v *volumeDir
 	if v, err = d.getMountedVolume(r.Name); err != nil {
@@ -146,9 +150,9 @@ func (d *driver) Mount(r *volume.MountRequest) (mr *volume.MountResponse, err er
 
 func (d *driver) Path(r *volume.PathRequest) (*volume.PathResponse, error) {
 	log.Debugf("Path %s", r.Name)
-	d.RLock()
+	d.lock.RLock()
 	v, err := d.getVolume(r.Name)
-	d.RUnlock()
+	d.lock.RUnlock()
 	pr := &volume.PathResponse{}
 	if err == nil {
 		pr.Mountpoint = v.logicalMountPoint()
@@ -162,8 +166,8 @@ func (d *driver) Unmount(r *volume.UnmountRequest) (err error) {
 	defer func() {
 		logResponse(err, "Unmount %s return", r.Name)
 	}()
-	d.Lock()
-	defer d.Unlock()
+	d.lock.Lock()
+	defer d.lock.Unlock()
 
 	var v *volumeDir
 	v, err = d.getVolume(r.Name)
@@ -199,24 +203,24 @@ func (d *driver) Unmount(r *volume.UnmountRequest) (err error) {
 func (d *driver) Get(r *volume.GetRequest) (gr *volume.GetResponse, err error) {
 	log.Debugf("Get %s", r.Name)
 	gr = &volume.GetResponse{}
-	d.RLock()
+	d.lock.RLock()
 	v, err := d.getVolume(r.Name)
 	if err == nil {
 		gr.Volume = v.asVolume(r.Name)
 	}
-	d.RUnlock()
+	d.lock.RUnlock()
 	logResponse(err, "Get %s return %v", r.Name, gr.Volume)
 	return gr, err
 }
 
 func (d *driver) List() (*volume.ListResponse, error) {
 	log.Debug("List")
-	d.RLock()
+	d.lock.RLock()
 	var vols = make([]*volume.Volume, 0, 32)
 	for _, m := range d.remoteMounts {
 		vols = m.appendVolumes(vols)
 	}
-	d.RUnlock()
+	d.lock.RUnlock()
 	sort.Slice(vols, func(i, j int) bool {
 		return vols[i].Name < vols[j].Name
 	})
@@ -228,15 +232,18 @@ func (d *driver) Capabilities() *volume.CapabilitiesResponse {
 	return &volume.CapabilitiesResponse{Capabilities: volume.Capability{Scope: "local"}}
 }
 
-func (d *driver) getRemoteMount(host string, port uint16) *mount {
+func (d *driver) getRemoteMount(host string, port uint16) (*mount, error) {
 	ps := strconv.Itoa(int(port))
 	key := net.JoinHostPort(host, ps)
 	if m, ok := d.remoteMounts[key]; ok {
-		return m
+		return m, nil
 	}
 	m := newMount(filepath.Join(d.volumePath, host, ps), host, port)
+	if err := m.mountVolume(); err != nil {
+		return nil, err
+	}
 	d.remoteMounts[key] = m
-	return m
+	return m, nil
 }
 
 func (d *driver) getVolume(n string) (*volumeDir, error) {