Add label filter support for volume

Since we added labels for volume, it is desired to have
filter support label for volume

Closes: #21416
Signed-off-by: Kai Qiang Wu(Kennan) <wkqwu@cn.ibm.com>

daemon/list.go

@@ -21,6 +21,7 @@ var acceptedVolumeFilterTags = map[string]bool{
 	"dangling": true,
 	"name":     true,
 	"driver":   true,
+	"label":    true,
 }
 
 var acceptedPsFilterTags = map[string]bool{
@@ -587,6 +588,21 @@ func (daemon *Daemon) filterVolumes(vols []volume.Volume, filter filters.Args) (
 				continue
 			}
 		}
+		if filter.Include("label") {
+			v, err := daemon.volumes.Get(vol.Name())
+			if err != nil {
+				return nil, err
+			}
+			if v, ok := v.(interface {
+				Labels() map[string]string
+			}); ok {
+				labels := v.Labels()
+
+				if !filter.MatchKVList("label", labels) {
+					continue
+				}
+			}
+		}
 		retVols = append(retVols, vol)
 	}
 	danglingOnly := false

integration-cli/docker_cli_volume_test.go

@@ -344,3 +344,33 @@ func (s *DockerSuite) TestVolumeCliCreateLabelMultiple(c *check.C) {
 		c.Assert(strings.TrimSpace(out), check.Equals, v)
 	}
 }
+
+func (s *DockerSuite) TestVolumeCliLsFilterLabels(c *check.C) {
+	testVol1 := "testvolcreatelabel-1"
+	out, _, err := dockerCmdWithError("volume", "create", "--label", "foo=bar1", "--name", testVol1)
+	c.Assert(err, check.IsNil)
+
+	testVol2 := "testvolcreatelabel-2"
+	out, _, err = dockerCmdWithError("volume", "create", "--label", "foo=bar2", "--name", testVol2)
+	c.Assert(err, check.IsNil)
+
+	out, _ = dockerCmd(c, "volume", "ls", "--filter", "label=foo")
+
+	// filter with label=key
+	c.Assert(out, checker.Contains, "testvolcreatelabel-1\n", check.Commentf("expected volume 'testvolcreatelabel-1' in output"))
+	c.Assert(out, checker.Contains, "testvolcreatelabel-2\n", check.Commentf("expected volume 'testvolcreatelabel-2' in output"))
+
+	out, _ = dockerCmd(c, "volume", "ls", "--filter", "label=foo=bar1")
+
+	// filter with label=key=value
+	c.Assert(out, checker.Contains, "testvolcreatelabel-1\n", check.Commentf("expected volume 'testvolcreatelabel-1' in output"))
+	c.Assert(out, check.Not(checker.Contains), "testvolcreatelabel-2\n", check.Commentf("expected volume 'testvolcreatelabel-2 in output"))
+
+	out, _ = dockerCmd(c, "volume", "ls", "--filter", "label=non-exist")
+	outArr := strings.Split(strings.TrimSpace(out), "\n")
+	c.Assert(len(outArr), check.Equals, 1, check.Commentf("\n%s", out))
+
+	out, _ = dockerCmd(c, "volume", "ls", "--filter", "label=foo=non-exist")
+	outArr = strings.Split(strings.TrimSpace(out), "\n")
+	c.Assert(len(outArr), check.Equals, 1, check.Commentf("\n%s", out))
+}