Add ignore socket test

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

archive/tar_test.go

@@ -1022,6 +1022,22 @@ func TestDiffTar(t *testing.T) {
 				fstest.CreateDir("/d3/", 0755),
 			),
 		},
+		{
+			name: "IgnoreSockets",
+			validators: []tarEntryValidator{
+				fileEntry("f2", []byte("content"), 0644),
+				// There should be _no_ socket here, despite the fstest.CreateSocket below
+				fileEntry("f3", []byte("content"), 0644),
+			},
+			a: fstest.Apply(
+				fstest.CreateFile("/f1", []byte("content"), 0644),
+			),
+			b: fstest.Apply(
+				fstest.CreateFile("/f2", []byte("content"), 0644),
+				fstest.CreateSocket("/s0", 0644),
+				fstest.CreateFile("/f3", []byte("content"), 0644),
+			),
+		},
 	}
 
 	for _, at := range tests {

vendor.conf

@@ -4,7 +4,7 @@ github.com/containerd/cgroups fe281dd265766145e943a034aa41086474ea6130
 github.com/containerd/typeurl f6943554a7e7e88b3c14aad190bf05932da84788
 github.com/containerd/fifo 3d5202aec260678c48179c56f40e6f38a095738c
 github.com/containerd/btrfs 2e1aa0ddf94f91fa282b6ed87c23bf0d64911244
-github.com/containerd/continuity d8fb8589b0e8e85b8c8bbaa8840226d0dfeb7371
+github.com/containerd/continuity 3e8f2ea4b190484acb976a5b378d373429639a1a
 github.com/coreos/go-systemd 48702e0da86bd25e76cfef347e2adeb434a0d0a6
 github.com/docker/go-metrics 4ea375f7759c82740c893fc030bc37088d2ec098
 github.com/docker/go-events 9461782956ad83b30282bf90e31fa6a70c255ba9

vendor/github.com/containerd/continuity/fs/fstest/file.go

@@ -2,6 +2,7 @@ package fstest
 
 import (
 	"io/ioutil"
+	"net"
 	"os"
 	"path/filepath"
 	"time"
@@ -107,6 +108,18 @@ func Link(oldname, newname string) Applier {
 //	}
 //}
 
+func CreateSocket(name string, perm os.FileMode) Applier {
+	return applyFn(func(root string) error {
+		fullPath := filepath.Join(root, name)
+		ln, err := net.Listen("unix", fullPath)
+		if err != nil {
+			return err
+		}
+		defer ln.Close()
+		return os.Chmod(fullPath, perm)
+	})
+}
+
 // Apply returns a new applier from the given appliers
 func Apply(appliers ...Applier) Applier {
 	return applyFn(func(root string) error {

vendor/github.com/containerd/continuity/fs/fstest/testsuite.go

@@ -74,6 +74,7 @@ var (
 		Symlink("libnothing.so", "/usr/local/lib/libnothing.so.2"),
 		CreateDir("/home", 0755),
 		CreateDir("/home/derek", 0700),
+		CreateDir("/var/run/socket", 0700),
 	)
 
 	// basicTest covers basic operations