Merge pull request #14885 from jlhawn/fix_cp_symlink

Fix copying of symlinks in containers

api/client/cp.go

@@ -232,6 +232,20 @@ func (cli *DockerCli) copyToContainer(srcPath, dstContainer, dstPath string) (er
 	// Prepare destination copy info by stat-ing the container path.
 	dstInfo := archive.CopyInfo{Path: dstPath}
 	dstStat, err := cli.statContainerPath(dstContainer, dstPath)
+
+	// If the destination is a symbolic link, we should evaluate it.
+	if err == nil && dstStat.Mode&os.ModeSymlink != 0 {
+		linkTarget := dstStat.LinkTarget
+		if !filepath.IsAbs(linkTarget) {
+			// Join with the parent directory.
+			dstParent, _ := archive.SplitPathDirEntry(dstPath)
+			linkTarget = filepath.Join(dstParent, linkTarget)
+		}
+
+		dstInfo.Path = linkTarget
+		dstStat, err = cli.statContainerPath(dstContainer, linkTarget)
+	}
+
 	// Ignore any error and assume that the parent directory of the destination
 	// path exists, in which case the copy may still succeed. If there is any
 	// type of conflict (e.g., non-directory overwriting an existing directory
@@ -242,15 +256,26 @@ func (cli *DockerCli) copyToContainer(srcPath, dstContainer, dstPath string) (er
 		dstInfo.Exists, dstInfo.IsDir = true, dstStat.Mode.IsDir()
 	}
 
-	var content io.Reader
+	var (
+		content         io.Reader
+		resolvedDstPath string
+	)
+
 	if srcPath == "-" {
 		// Use STDIN.
 		content = os.Stdin
+		resolvedDstPath = dstInfo.Path
 		if !dstInfo.IsDir {
 			return fmt.Errorf("destination %q must be a directory", fmt.Sprintf("%s:%s", dstContainer, dstPath))
 		}
 	} else {
-		srcArchive, err := archive.TarResource(srcPath)
+		// Prepare source copy info.
+		srcInfo, err := archive.CopyInfoSourcePath(srcPath)
+		if err != nil {
+			return err
+		}
+
+		srcArchive, err := archive.TarResource(srcInfo)
 		if err != nil {
 			return err
 		}
@@ -262,12 +287,6 @@ func (cli *DockerCli) copyToContainer(srcPath, dstContainer, dstPath string) (er
 		// it to the specified directory in the container we get the disired
 		// copy behavior.
 
-		// Prepare source copy info.
-		srcInfo, err := archive.CopyInfoStatPath(srcPath, true)
-		if err != nil {
-			return err
-		}
-
 		// See comments in the implementation of `archive.PrepareArchiveCopy`
 		// for exactly what goes into deciding how and whether the source
 		// archive needs to be altered for the correct copy behavior when it is
@@ -280,12 +299,12 @@ func (cli *DockerCli) copyToContainer(srcPath, dstContainer, dstPath string) (er
 		}
 		defer preparedArchive.Close()
 
-		dstPath = dstDir
+		resolvedDstPath = dstDir
 		content = preparedArchive
 	}
 
 	query := make(url.Values, 2)
-	query.Set("path", filepath.ToSlash(dstPath)) // Normalize the paths used in the API.
+	query.Set("path", filepath.ToSlash(resolvedDstPath)) // Normalize the paths used in the API.
 	// Do not allow for an existing directory to be overwritten by a non-directory and vice versa.
 	query.Set("noOverwriteDirNonDir", "true")
 

api/types/types.go

@@ -130,14 +130,13 @@ type CopyConfig struct {
 
 // ContainerPathStat is used to encode the header from
 // 	GET /containers/{name:.*}/archive
-// "name" is the file or directory name.
-// "path" is the absolute path to the resource in the container.
+// "name" is basename of the resource.
 type ContainerPathStat struct {
-	Name  string      `json:"name"`
-	Path  string      `json:"path"`
-	Size  int64       `json:"size"`
-	Mode  os.FileMode `json:"mode"`
-	Mtime time.Time   `json:"mtime"`
+	Name       string      `json:"name"`
+	Size       int64       `json:"size"`
+	Mode       os.FileMode `json:"mode"`
+	Mtime      time.Time   `json:"mtime"`
+	LinkTarget string      `json:"linkTarget"`
 }
 
 // GET "/containers/{name:.*}/top"