'podman cp' copy between host and container

Signed-off-by: Qi Wang <qiwan@redhat.com>
2025-07-02 08:47:43 +08:00 · 2019-01-07 11:16:29 -05:00
parent 112a5ab20c
commit 36d962990a
6 changed files with 449 additions and 13 deletions
--- a/cmd/podman/cliconfig/create.go
+++ b/cmd/podman/cliconfig/create.go
@ -20,3 +20,7 @@ type BuildValues struct {
 	*buildahcli.NameSpaceResults
 	*buildahcli.LayerResults
 }
+
+type CpValues struct {
+	PodmanCommand
+}
--- a/cmd/podman/cp.go
+++ b/cmd/podman/cp.go
@ -0,0 +1,257 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/containers/buildah/util"
+	"github.com/containers/libpod/cmd/podman/cliconfig"
+	"github.com/containers/libpod/cmd/podman/libpodruntime"
+	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/pkg/chrootuser"
+	"github.com/containers/storage"
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/chrootarchive"
+	"github.com/containers/storage/pkg/idtools"
+	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+var (
+	cpCommand cliconfig.CpValues
+
+	cpDescription = "Copy files/folders between a container and the local filesystem"
+	_cpCommand    = &cobra.Command{
+		Use:   "cp",
+		Short: "Copy files/folders between a container and the local filesystem",
+		Long:  cpDescription,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cpCommand.InputArgs = args
+			cpCommand.GlobalFlags = MainGlobalOpts
+			return cpCmd(&cpCommand)
+		},
+		Example: "[CONTAINER:]SRC_PATH [CONTAINER:]DEST_PATH",
+	}
+)
+
+func init() {
+	cpCommand.Command = _cpCommand
+	rootCmd.AddCommand(cpCommand.Command)
+}
+
+func cpCmd(c *cliconfig.CpValues) error {
+	args := c.InputArgs
+	if len(args) != 2 {
+		return errors.Errorf("you must provide a source path and a destination path")
+	}
+
+	runtime, err := libpodruntime.GetRuntime(&c.PodmanCommand)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+
+	return copyBetweenHostAndContainer(runtime, args[0], args[1])
+}
+
+func copyBetweenHostAndContainer(runtime *libpod.Runtime, src string, dest string) error {
+
+	srcCtr, srcPath := parsePath(runtime, src)
+	destCtr, destPath := parsePath(runtime, dest)
+
+	if (srcCtr == nil && destCtr == nil) || (srcCtr != nil && destCtr != nil) {
+		return errors.Errorf("invalid arguments %s, %s you must use just one container", src, dest)
+	}
+
+	if len(srcPath) == 0 || len(destPath) == 0 {
+		return errors.Errorf("invalid arguments %s, %s you must specify paths", src, dest)
+	}
+	ctr := srcCtr
+	isFromHostToCtr := (ctr == nil)
+	if isFromHostToCtr {
+		ctr = destCtr
+	}
+
+	mountPoint, err := ctr.Mount()
+	if err != nil {
+		return err
+	}
+	defer ctr.Unmount(false)
+	user, err := getUser(mountPoint, ctr.User())
+	if err != nil {
+		return err
+	}
+	idMappingOpts, err := ctr.IDMappings()
+	if err != nil {
+		return errors.Wrapf(err, "error getting IDMappingOptions")
+	}
+	containerOwner := idtools.IDPair{UID: int(user.UID), GID: int(user.GID)}
+	hostUID, hostGID, err := util.GetHostIDs(convertIDMap(idMappingOpts.UIDMap), convertIDMap(idMappingOpts.GIDMap), user.UID, user.GID)
+	if err != nil {
+		return err
+	}
+
+	hostOwner := idtools.IDPair{UID: int(hostUID), GID: int(hostGID)}
+
+	var glob []string
+	if isFromHostToCtr {
+		if filepath.IsAbs(destPath) {
+			destPath = filepath.Join(mountPoint, destPath)
+
+		} else {
+			if err = idtools.MkdirAllAndChownNew(filepath.Join(mountPoint, ctr.WorkingDir()), 0755, hostOwner); err != nil {
+				return errors.Wrapf(err, "error creating directory %q", destPath)
+			}
+			destPath = filepath.Join(mountPoint, ctr.WorkingDir(), destPath)
+		}
+	} else {
+		if filepath.IsAbs(srcPath) {
+			srcPath = filepath.Join(mountPoint, srcPath)
+		} else {
+			srcPath = filepath.Join(mountPoint, ctr.WorkingDir(), srcPath)
+		}
+	}
+	glob, err = filepath.Glob(srcPath)
+	if err != nil {
+		return errors.Wrapf(err, "invalid glob %q", srcPath)
+	}
+	if len(glob) == 0 {
+		glob = append(glob, srcPath)
+	}
+	if !filepath.IsAbs(destPath) {
+		dir, err := os.Getwd()
+		if err != nil {
+			return errors.Wrapf(err, "err getting current working directory")
+		}
+		destPath = filepath.Join(dir, destPath)
+	}
+
+	var lastError error
+	for _, src := range glob {
+		err := copy(src, destPath, dest, idMappingOpts, &containerOwner)
+		if lastError != nil {
+			logrus.Error(lastError)
+		}
+		lastError = err
+	}
+	return lastError
+}
+
+func getUser(mountPoint string, userspec string) (specs.User, error) {
+	uid, gid, err := chrootuser.GetUser(mountPoint, userspec)
+	u := specs.User{
+		UID:      uid,
+		GID:      gid,
+		Username: userspec,
+	}
+	if !strings.Contains(userspec, ":") {
+		groups, err2 := chrootuser.GetAdditionalGroupsForUser(mountPoint, uint64(u.UID))
+		if err2 != nil {
+			if errors.Cause(err2) != chrootuser.ErrNoSuchUser && err == nil {
+				err = err2
+			}
+		} else {
+			u.AdditionalGids = groups
+		}
+
+	}
+	return u, err
+}
+
+func parsePath(runtime *libpod.Runtime, path string) (*libpod.Container, string) {
+	pathArr := strings.SplitN(path, ":", 2)
+	if len(pathArr) == 2 {
+		ctr, err := runtime.LookupContainer(pathArr[0])
+		if err == nil {
+			return ctr, pathArr[1]
+		}
+	}
+	return nil, path
+}
+
+func getPathInfo(path string) (string, os.FileInfo, error) {
+	path, err := filepath.EvalSymlinks(path)
+	if err != nil {
+		return "", nil, errors.Wrapf(err, "error evaluating symlinks %q", path)
+	}
+	srcfi, err := os.Stat(path)
+	if err != nil {
+		return "", nil, errors.Wrapf(err, "error reading path %q", path)
+	}
+	return path, srcfi, nil
+}
+
+func copy(src, destPath, dest string, idMappingOpts storage.IDMappingOptions, chownOpts *idtools.IDPair) error {
+	srcPath, err := filepath.EvalSymlinks(src)
+	if err != nil {
+		return errors.Wrapf(err, "error evaluating symlinks %q", srcPath)
+	}
+
+	srcPath, srcfi, err := getPathInfo(srcPath)
+	if err != nil {
+		return err
+	}
+	destdir := destPath
+	if !srcfi.IsDir() && !strings.HasSuffix(dest, string(os.PathSeparator)) {
+		destdir = filepath.Dir(destPath)
+	}
+	if err = os.MkdirAll(destdir, 0755); err != nil {
+		return errors.Wrapf(err, "error creating directory %q", destdir)
+	}
+
+	// return functions for copying items
+	copyFileWithTar := chrootarchive.CopyFileWithTarAndChown(chownOpts, digest.Canonical.Digester().Hash(), idMappingOpts.UIDMap, idMappingOpts.GIDMap)
+	copyWithTar := chrootarchive.CopyWithTarAndChown(chownOpts, digest.Canonical.Digester().Hash(), idMappingOpts.UIDMap, idMappingOpts.GIDMap)
+	untarPath := chrootarchive.UntarPathAndChown(chownOpts, digest.Canonical.Digester().Hash(), idMappingOpts.UIDMap, idMappingOpts.GIDMap)
+
+	if srcfi.IsDir() {
+
+		logrus.Debugf("copying %q to %q", srcPath+string(os.PathSeparator)+"*", dest+string(os.PathSeparator)+"*")
+		if err = copyWithTar(srcPath, destPath); err != nil {
+			return errors.Wrapf(err, "error copying %q to %q", srcPath, dest)
+		}
+		return nil
+	}
+	if !archive.IsArchivePath(srcPath) {
+		// This srcPath is a file, and either it's not an
+		// archive, or we don't care whether or not it's an
+		// archive.
+		destfi, err := os.Stat(destPath)
+		if err != nil {
+			if !os.IsNotExist(err) {
+				return errors.Wrapf(err, "failed to get stat of dest path %s", destPath)
+			}
+		}
+		if destfi != nil && destfi.IsDir() {
+			destPath = filepath.Join(destPath, filepath.Base(srcPath))
+		}
+		// Copy the file, preserving attributes.
+		logrus.Debugf("copying %q to %q", srcPath, destPath)
+		if err = copyFileWithTar(srcPath, destPath); err != nil {
+			return errors.Wrapf(err, "error copying %q to %q", srcPath, destPath)
+		}
+		return nil
+	}
+	// We're extracting an archive into the destination directory.
+	logrus.Debugf("extracting contents of %q into %q", srcPath, destPath)
+	if err = untarPath(srcPath, destPath); err != nil {
+		return errors.Wrapf(err, "error extracting %q into %q", srcPath, destPath)
+	}
+	return nil
+}
+
+func convertIDMap(idMaps []idtools.IDMap) (convertedIDMap []specs.LinuxIDMapping) {
+	for _, idmap := range idMaps {
+		tempIDMap := specs.LinuxIDMapping{
+			ContainerID: uint32(idmap.ContainerID),
+			HostID:      uint32(idmap.HostID),
+			Size:        uint32(idmap.Size),
+		}
+		convertedIDMap = append(convertedIDMap, tempIDMap)
+	}
+	return convertedIDMap
+}
--- a/commands.md
+++ b/commands.md
@ -16,7 +16,7 @@
 | [podman-container-refresh(1)](/docs/podman-container-refresh.1.md)       | Refresh all containers state in database                  ||
 | [podman-container-restore(1)](/docs/podman-container-restore.1.md)       | Restores one or more running containers                   ||
 | [podman-container-runlabel(1)](/docs/podman-container-runlabel.1.md)     | Execute Image Label Method	     			       ||
-| [podman-cp(1)](/docs/podman-cp.1.md)                     | Instead of providing a `podman cp` command, the man page `podman-cp` describes how to use the `podman mount` command to have even more flexibility and functionality||
+| [podman-cp(1)](/docs/podman-cp.1.md)                     | Copy files/folders between a container and the local filesystem           ||
 | [podman-create(1)](/docs/podman-create.1.md)             | Create a new container                                                    ||
 | [podman-diff(1)](/docs/podman-diff.1.md)                 | Inspect changes on a container or image's filesystem                      |[![...](/docs/play.png)](https://asciinema.org/a/FXfWB9CKYFwYM4EfqW3NSZy1G)|
 | [podman-exec(1)](/docs/podman-exec.1.md)                 | Execute a command in a running container
--- a/docs/podman-cp.1.md
+++ b/docs/podman-cp.1.md
@ -3,20 +3,70 @@
 ## NAME
 podman\-cp - Copy files/folders between a container and the local filesystem

-## Description
-We chose not to implement the `cp` feature in `podman` even though the upstream Docker
-project has it. We have a much stronger capability.  Using standard podman-mount
-and podman-umount, we can take advantage of the entire linux tool chain, rather
+## SYNOPSIS
+**podman cp [CONTAINER:]SRC_PATH [CONTAINER:]DEST_PATH**
+
+## DESCRIPTION
+Copies the contents of **SRC_PATH** to the **DEST_PATH**. You can copy from the containers's filesystem to the local machine or the reverse, from the local filesystem to the container.
+
+The CONTAINER can be a running or stopped container. The **SRC_PATH** or **DEST_PATH** can be a file or directory.
+
+The **podman cp** command assumes container paths are relative to the container's / (root) directory.
+
+This means supplying the initial forward slash is optional;
+
+The command sees **compassionate_darwin:/tmp/foo/myfile.txt** and **compassionate_darwin:tmp/foo/myfile.txt** as identical.
+
+Local machine paths can be an absolute or relative value.
+The command interprets a local machine's relative paths as relative to the current working directory where **podman cp** is run.
+
+Assuming a path separator of /, a first argument of **SRC_PATH** and second argument of **DEST_PATH**, the behavior is as follows:
+
+**SRC_PATH** specifies a file
+  - **DEST_PATH** does not exist
+	- the file is saved to a file created at **DEST_PATH**
+  - **DEST_PATH** does not exist and ends with /
+	- **DEST_PATH** is created as a directory and the file is copied into this directory using the basename from **SRC_PATH**
+  - **DEST_PATH** exists and is a file
+	- the destination is overwritten with the source file's contents
+  - **DEST_PATH** exists and is a directory
+	- the file is copied into this directory using the basename from **SRC_PATH**
+
+**SRC_PATH** specifies a directory
+  - **DEST_PATH** does not exist
+	- **DEST_PATH** is created as a directory and the contents of the source directory are copied into this directory
+  - **DEST_PATH** exists and is a file
+	- Error condition: cannot copy a directory to a file
+  - **DEST_PATH** exists and is a directory
+	- **SRC_PATH** ends with /
+		- the source directory is copied into this directory
+	- **SRC_PATH** ends with /. (that is: slash followed by dot)
+		- the content of the source directory is copied into this directory
+
+The command requires **SRC_PATH** and **DEST_PATH** to exist according to the above rules.
+
+If **SRC_PATH** is local and is a symbolic link, the symbolic target, is copied by default.
+
+A colon (:) is used as a delimiter between CONTAINER and its path.
+
+You can also use : when specifying paths to a **SRC_PATH** or **DEST_PATH** on a local machine, for example, `file:name.txt`.
+
+If you use a : in a local machine path, you must be explicit with a relative or absolute path, for example:
+	`/path/to/file:name.txt` or `./file:name.txt`
+
+
+## ALTERNATIVES
+
+Podman has much stronger capabilities than just `podman cp` to achieve copy files between host and container.
+
+Using standard podman-mount and podman-umount takes advantage of the entire linux tool chain, rather
 then just cp.

-If a user wants to copy contents out of a container or into a container, they
-can execute a few simple commands.
+If a user wants to copy contents out of a container or into a container, they can execute a few simple commands.

-You can copy from the container's file system to the local machine or the
-reverse, from the local filesystem to the container.
+You can copy from the container's file system to the local machine or the reverse, from the local filesystem to the container.

-If you want to copy the /etc/foobar directory out of a container and onto /tmp
-on the host, you could execute the following commands:
+If you want to copy the /etc/foobar directory out of a container and onto /tmp on the host, you could execute the following commands:

 	mnt=$(podman mount CONTAINERID)
 	cp -R ${mnt}/etc/foobar /tmp
@ -40,5 +90,15 @@ This shows that using `podman mount` and `podman umount` you can use all of the
 standard linux tools for moving files into and out of containers, not just
 the cp command.

+## EXAMPLE
+
+podman cp /myapp/app.conf containerID:/myapp/app.conf
+
+podman cp /home/myuser/myfiles.tar containerID:/tmp
+
+podman cp containerID:/myapp/ /myapp/
+
+podman cp containerID:/home/myuser/. /home/myuser/
+
 ## SEE ALSO
 podman(1), podman-mount(1), podman-umount(1)
--- a/test/e2e/cp_test.go
+++ b/test/e2e/cp_test.go
@ -0,0 +1,115 @@
+// +build !remoteclient
+
+package integration
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	. "github.com/containers/libpod/test/utils"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Podman cp", func() {
+	var (
+		tempdir    string
+		err        error
+		podmanTest *PodmanTestIntegration
+	)
+
+	BeforeEach(func() {
+		tempdir, err = CreateTempDirInTempDir()
+		if err != nil {
+			os.Exit(1)
+		}
+		podmanTest = PodmanTestCreate(tempdir)
+		podmanTest.RestoreAllArtifacts()
+	})
+
+	AfterEach(func() {
+		podmanTest.Cleanup()
+		f := CurrentGinkgoTestDescription()
+		timedResult := fmt.Sprintf("Test: %s completed in %f seconds", f.TestText, f.Duration.Seconds())
+		GinkgoWriter.Write([]byte(timedResult))
+	})
+
+	It("podman cp file", func() {
+		path, err := os.Getwd()
+		if err != nil {
+			os.Exit(1)
+		}
+		filePath := filepath.Join(path, "cp_test.txt")
+		fromHostToContainer := []byte("copy from host to container")
+		err = ioutil.WriteFile(filePath, fromHostToContainer, 0644)
+		if err != nil {
+			os.Exit(1)
+		}
+
+		session := podmanTest.Podman([]string{"create", ALPINE, "cat", "foo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		name := session.OutputToString()
+
+		session = podmanTest.Podman([]string{"cp", filepath.Join(path, "cp_test.txt"), name + ":foo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		session = podmanTest.Podman([]string{"start", "-a", name})
+		session.WaitWithDefaultTimeout()
+
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(Equal("copy from host to container"))
+
+		session = podmanTest.Podman([]string{"cp", name + ":foo", filepath.Join(path, "cp_from_container")})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		c := exec.Command("cat", filepath.Join(path, "cp_from_container"))
+		output, err := c.Output()
+		if err != nil {
+			os.Exit(1)
+		}
+		Expect(string(output)).To(Equal("copy from host to container"))
+	})
+
+	It("podman cp file to dir", func() {
+		path, err := os.Getwd()
+		if err != nil {
+			os.Exit(1)
+		}
+		filePath := filepath.Join(path, "cp_test.txt")
+		fromHostToContainer := []byte("copy from host to container directory")
+		err = ioutil.WriteFile(filePath, fromHostToContainer, 0644)
+		if err != nil {
+			os.Exit(1)
+		}
+		session := podmanTest.Podman([]string{"create", ALPINE, "ls", "foodir/"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		session = podmanTest.Podman([]string{"ps", "-a", "-q"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		name := session.OutputToString()
+
+		session = podmanTest.Podman([]string{"cp", filepath.Join(path, "cp_test.txt"), name + ":foodir/"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		session = podmanTest.Podman([]string{"start", "-a", name})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(Equal("cp_test.txt"))
+
+		session = podmanTest.Podman([]string{"cp", name + ":foodir/cp_test.txt", path + "/receive/"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		c := exec.Command("cat", filepath.Join(path, "receive", "cp_test.txt"))
+		output, err := c.Output()
+		if err != nil {
+			os.Exit(1)
+		}
+		Expect(string(output)).To(Equal("copy from host to container directory"))
+	})
+})
--- a/transfer.md
+++ b/transfer.md
@ -37,11 +37,11 @@ There are other equivalents for these tools

 | Existing Step | `Podman` (and friends) |
 | :--- | :--- |
-| `docker attach`  | [`podman exec`](./docs/podman-attach.1.md)      |
+| `docker attach`  | [`podman attach`](./docs/podman-attach.1.md)    |
+| `docker cp`      | [`podman cp`](./docs/podman-cp.1.md)            |
 | `docker build`   | [`podman build`](./docs/podman-build.1.md)      |
 | `docker commit`  | [`podman commit`](./docs/podman-commit.1.md)    |
 | `docker container`|[`podman container`](./docs/podman-container.1.md) |
-| `docker cp`      | [`podman mount`](./docs/podman-cp.1.md) ****    |
 | `docker create`  | [`podman create`](./docs/podman-create.1.md)    |
 | `docker diff`    | [`podman diff`](./docs/podman-diff.1.md)        |
 | `docker export`  | [`podman export`](./docs/podman-export.1.md)    |