Fix regression when filtering container names using a leading slash

Commit 5c8da2e96738addd8a175e5b9a23b8c37d4a4dfe updated the filtering behavior
to match container-names without having to specify the leading slash.

This change caused a regression in situations where a regex was provided as
filter, using an explicit leading slash (`--filter name=^/mycontainername`).

This fix changes the filters to match containers both with, and without the
leading slash, effectively making the leading slash optional when filtering.

With this fix, filters with and without a leading slash produce the same result:

    $ docker ps --filter name=^a
    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    21afd6362b0c        busybox             "sh"                2 minutes ago       Up 2 minutes                            a2
    56e53770e316        busybox             "sh"                2 minutes ago       Up 2 minutes                            a1

    $ docker ps --filter name=^/a
    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    21afd6362b0c        busybox             "sh"                2 minutes ago       Up 2 minutes                            a2
    56e53770e316        busybox             "sh"                3 minutes ago       Up 3 minutes                            a1

    $ docker ps --filter name=^b
    CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
    b69003b6a6fe        busybox             "sh"                About a minute ago   Up About a minute                       b1

    $ docker ps --filter name=^/b
    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    b69003b6a6fe        busybox             "sh"                56 seconds ago      Up 54 seconds                           b1

    $ docker ps --filter name=/a
    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    21afd6362b0c        busybox             "sh"                3 minutes ago       Up 3 minutes                            a2
    56e53770e316        busybox             "sh"                4 minutes ago       Up 4 minutes                            a1

    $ docker ps --filter name=a
    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    21afd6362b0c        busybox             "sh"                3 minutes ago       Up 3 minutes                            a2
    56e53770e316        busybox             "sh"                4 minutes ago       Up 4 minutes                            a1

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/list.go

@@ -146,7 +146,8 @@ func (daemon *Daemon) filterByNameIDMatches(view container.View, ctx *listContex
 				continue
 			}
 			for _, eachName := range idNames {
-				if ctx.filters.Match("name", strings.TrimPrefix(eachName, "/")) {
+				// match both on container name with, and without slash-prefix
+				if ctx.filters.Match("name", eachName) || ctx.filters.Match("name", strings.TrimPrefix(eachName, "/")) {
 					matches[id] = true
 				}
 			}
@@ -429,7 +430,7 @@ func includeContainerInList(container *container.Snapshot, ctx *listContext) ite
 	}
 
 	// Do not include container if the name doesn't match
-	if !ctx.filters.Match("name", strings.TrimPrefix(container.Name, "/")) {
+	if !ctx.filters.Match("name", container.Name) && !ctx.filters.Match("name", strings.TrimPrefix(container.Name, "/")) {
 		return excludeContainer
 	}
 

daemon/list_test.go

@@ -4,7 +4,6 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 
 	"github.com/docker/docker/api/types"
@@ -35,6 +34,7 @@ func TestMain(m *testing.M) {
 // work against it. It takes in a pointer to Daemon so that
 // minor operations are not repeated by the caller
 func setupContainerWithName(t *testing.T, name string, daemon *Daemon) *container.Container {
+	t.Helper()
 	var (
 		id              = uuid.New()
 		computedImageID = digest.FromString(id)
@@ -46,6 +46,9 @@ func setupContainerWithName(t *testing.T, name string, daemon *Daemon) *containe
 
 	c := container.NewBaseContainer(id, cRoot)
 	// these are for passing includeContainerInList
+	if name[0] != '/' {
+		name = "/" + name
+	}
 	c.Name = name
 	c.Running = true
 	c.HostConfig = &containertypes.HostConfig{}
@@ -68,7 +71,7 @@ func setupContainerWithName(t *testing.T, name string, daemon *Daemon) *containe
 func containerListContainsName(containers []*types.Container, name string) bool {
 	for _, container := range containers {
 		for _, containerName := range container.Names {
-			if strings.TrimPrefix(containerName, "/") == name {
+			if containerName == name {
 				return true
 			}
 		}
@@ -110,16 +113,33 @@ func TestNameFilter(t *testing.T) {
 	containerList, err := d.Containers(&types.ContainerListOptions{
 		Filters: filters.NewArgs(filters.Arg("name", "^a")),
 	})
-	assert.Assert(t, err == nil)
+	assert.NilError(t, err)
 	assert.Assert(t, is.Len(containerList, 2))
 	assert.Assert(t, containerListContainsName(containerList, one.Name))
 	assert.Assert(t, containerListContainsName(containerList, two.Name))
 
+	// Same as above but with slash prefix should produce the same result
+	containerListWithPrefix, err := d.Containers(&types.ContainerListOptions{
+		Filters: filters.NewArgs(filters.Arg("name", "^/a")),
+	})
+	assert.NilError(t, err)
+	assert.Assert(t, is.Len(containerListWithPrefix, 2))
+	assert.Assert(t, containerListContainsName(containerListWithPrefix, one.Name))
+	assert.Assert(t, containerListContainsName(containerListWithPrefix, two.Name))
+
 	// Same as above but make sure it works for exact names
 	containerList, err = d.Containers(&types.ContainerListOptions{
 		Filters: filters.NewArgs(filters.Arg("name", "b1")),
 	})
-	assert.Assert(t, err == nil)
+	assert.NilError(t, err)
 	assert.Assert(t, is.Len(containerList, 1))
 	assert.Assert(t, containerListContainsName(containerList, three.Name))
+
+	// Same as above but with slash prefix should produce the same result
+	containerListWithPrefix, err = d.Containers(&types.ContainerListOptions{
+		Filters: filters.NewArgs(filters.Arg("name", "/b1")),
+	})
+	assert.NilError(t, err)
+	assert.Assert(t, is.Len(containerListWithPrefix, 1))
+	assert.Assert(t, containerListContainsName(containerListWithPrefix, three.Name))
 }