Propagate unmount events to the external volume drivers.

Signed-off-by: David Calavera <david.calavera@gmail.com>
Upstream-commit: d592778f4a75d36745aaffaf73c0775ecd420545
Component: engine

components/engine/volume/drivers/adapter.go

@@ -16,7 +16,10 @@ func (a *volumeDriverAdapter) Create(name string) (volume.Volume, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &volumeAdapter{a.proxy, name, a.name}, nil
+	return &volumeAdapter{
+		proxy:      a.proxy,
+		name:       name,
+		driverName: a.name}, nil
 }
 
 func (a *volumeDriverAdapter) Remove(v volume.Volume) error {
@@ -27,6 +30,7 @@ type volumeAdapter struct {
 	proxy      *volumeDriverProxy
 	name       string
 	driverName string
+	eMount     string // ephemeral host volume path
 }
 
 func (a *volumeAdapter) Name() string {
@@ -38,12 +42,17 @@ func (a *volumeAdapter) DriverName() string {
 }
 
 func (a *volumeAdapter) Path() string {
+	if len(a.eMount) > 0 {
+		return a.eMount
+	}
 	m, _ := a.proxy.Path(a.name)
 	return m
 }
 
 func (a *volumeAdapter) Mount() (string, error) {
-	return a.proxy.Mount(a.name)
+	var err error
+	a.eMount, err = a.proxy.Mount(a.name)
+	return a.eMount, err
 }
 
 func (a *volumeAdapter) Unmount() error {

components/engine/volume/drivers/extpoint.go

@@ -1,9 +1,9 @@
 package volumedrivers
 
 import (
+	"fmt"
 	"sync"
 
-	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/pkg/plugins"
 	"github.com/docker/docker/volume"
 )
@@ -52,9 +52,9 @@ func Lookup(name string) (volume.Driver, error) {
 	}
 	pl, err := plugins.Get(name, "VolumeDriver")
 	if err != nil {
-		logrus.Errorf("Error: %v", err)
-		return nil, err
+		return nil, fmt.Errorf("Error looking up volume plugin %s: %v", name, err)
 	}
+
 	d := NewVolumeDriver(name, pl.Client)
 	drivers.extensions[name] = d
 	return d, nil

components/engine/volume/drivers/proxy.go

@@ -1,5 +1,7 @@
 package volumedrivers
 
+import "fmt"
+
 // currently created by hand. generation tool would generate this like:
 // $ rpc-gen volume/drivers/api.go VolumeDriver > volume/drivers/proxy.go
 
@@ -21,9 +23,9 @@ func (pp *volumeDriverProxy) Create(name string) error {
 	var ret volumeDriverResponse
 	err := pp.c.Call("VolumeDriver.Create", args, &ret)
 	if err != nil {
-		return err
+		return pp.fmtError(name, err)
 	}
-	return ret.Err
+	return pp.fmtError(name, ret.Err)
 }
 
 func (pp *volumeDriverProxy) Remove(name string) error {
@@ -31,27 +33,27 @@ func (pp *volumeDriverProxy) Remove(name string) error {
 	var ret volumeDriverResponse
 	err := pp.c.Call("VolumeDriver.Remove", args, &ret)
 	if err != nil {
-		return err
+		return pp.fmtError(name, err)
 	}
-	return ret.Err
+	return pp.fmtError(name, ret.Err)
 }
 
 func (pp *volumeDriverProxy) Path(name string) (string, error) {
 	args := volumeDriverRequest{name}
 	var ret volumeDriverResponse
 	if err := pp.c.Call("VolumeDriver.Path", args, &ret); err != nil {
-		return "", err
+		return "", pp.fmtError(name, err)
 	}
-	return ret.Mountpoint, ret.Err
+	return ret.Mountpoint, pp.fmtError(name, ret.Err)
 }
 
 func (pp *volumeDriverProxy) Mount(name string) (string, error) {
 	args := volumeDriverRequest{name}
 	var ret volumeDriverResponse
 	if err := pp.c.Call("VolumeDriver.Mount", args, &ret); err != nil {
-		return "", err
+		return "", pp.fmtError(name, err)
 	}
-	return ret.Mountpoint, ret.Err
+	return ret.Mountpoint, pp.fmtError(name, ret.Err)
 }
 
 func (pp *volumeDriverProxy) Unmount(name string) error {
@@ -59,7 +61,14 @@ func (pp *volumeDriverProxy) Unmount(name string) error {
 	var ret volumeDriverResponse
 	err := pp.c.Call("VolumeDriver.Unmount", args, &ret)
 	if err != nil {
-		return err
+		return pp.fmtError(name, err)
 	}
-	return ret.Err
+	return pp.fmtError(name, ret.Err)
+}
+
+func (pp *volumeDriverProxy) fmtError(name string, err error) error {
+	if err == nil {
+		return nil
+	}
+	return fmt.Errorf("External volume driver request failed for %s: %v", name, err)
 }