remote copy

Implement `podman-remote cp` and break out the logic from the previously
added `pkg/copy` into it's basic building blocks and move them up into
the `ContainerEngine` interface and `cmd/podman`.

The `--pause` and `--extract` flags are now deprecated and turned into
nops.

Note that this commit is vendoring a non-release version of Buildah to
pull in updates to the copier package.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 172 insertions, 0 deletions

diff --git a/pkg/domain/infra/abi/archive.go b/pkg/domain/infra/abi/archive.go
new file mode 100644
index 000000000..809813756
--- /dev/null
+++ b/pkg/domain/infra/abi/archive.go
@@ -0,0 +1,172 @@
+package abi
+
+import (
+	"context"
+	"io"
+	"strings"
+
+	buildahCopiah "github.com/containers/buildah/copier"
+	"github.com/containers/buildah/pkg/chrootuser"
+	"github.com/containers/buildah/util"
+	"github.com/containers/podman/v2/libpod"
+	"github.com/containers/podman/v2/pkg/domain/entities"
+	"github.com/containers/storage"
+	"github.com/containers/storage/pkg/archive"
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+// NOTE: Only the parent directory of the container path must exist.  The path
+// itself may be created while copying.
+func (ic *ContainerEngine) ContainerCopyFromArchive(ctx context.Context, nameOrID string, containerPath string, reader io.Reader) (entities.ContainerCopyFunc, error) {
+	container, err := ic.Libpod.LookupContainer(nameOrID)
+	if err != nil {
+		return nil, err
+	}
+
+	unmount := func() {
+		if err := container.Unmount(false); err != nil {
+			logrus.Errorf("Error unmounting container: %v", err)
+		}
+	}
+
+	_, resolvedRoot, resolvedContainerPath, err := ic.containerStat(container, containerPath)
+	if err != nil {
+		unmount()
+		return nil, err
+	}
+
+	decompressed, err := archive.DecompressStream(reader)
+	if err != nil {
+		unmount()
+		return nil, err
+	}
+
+	idMappings, idPair, err := getIDMappingsAndPair(container, resolvedRoot)
+	if err != nil {
+		unmount()
+		return nil, err
+	}
+
+	logrus.Debugf("Container copy *to* %q (resolved: %q) on container %q (ID: %s)", containerPath, resolvedContainerPath, container.Name(), container.ID())
+
+	return func() error {
+		defer unmount()
+		defer decompressed.Close()
+		putOptions := buildahCopiah.PutOptions{
+			UIDMap:     idMappings.UIDMap,
+			GIDMap:     idMappings.GIDMap,
+			ChownDirs:  idPair,
+			ChownFiles: idPair,
+		}
+		return buildahCopiah.Put(resolvedRoot, resolvedContainerPath, putOptions, decompressed)
+	}, nil
+}
+
+func (ic *ContainerEngine) ContainerCopyToArchive(ctx context.Context, nameOrID string, containerPath string, writer io.Writer) (entities.ContainerCopyFunc, error) {
+	container, err := ic.Libpod.LookupContainer(nameOrID)
+	if err != nil {
+		return nil, err
+	}
+
+	unmount := func() {
+		if err := container.Unmount(false); err != nil {
+			logrus.Errorf("Error unmounting container: %v", err)
+		}
+	}
+
+	// Make sure that "/" copies the *contents* of the mount point and not
+	// the directory.
+	if containerPath == "/" {
+		containerPath = "/."
+	}
+
+	_, resolvedRoot, resolvedContainerPath, err := ic.containerStat(container, containerPath)
+	if err != nil {
+		unmount()
+		return nil, err
+	}
+
+	idMappings, idPair, err := getIDMappingsAndPair(container, resolvedRoot)
+	if err != nil {
+		unmount()
+		return nil, err
+	}
+
+	logrus.Debugf("Container copy *from* %q (resolved: %q) on container %q (ID: %s)", containerPath, resolvedContainerPath, container.Name(), container.ID())
+
+	return func() error {
+		defer container.Unmount(false)
+		getOptions := buildahCopiah.GetOptions{
+			// Unless the specified path ends with ".", we want to copy the base directory.
+			KeepDirectoryNames: !strings.HasSuffix(resolvedContainerPath, "."),
+			UIDMap:             idMappings.UIDMap,
+			GIDMap:             idMappings.GIDMap,
+			ChownDirs:          idPair,
+			ChownFiles:         idPair,
+		}
+		return buildahCopiah.Get(resolvedRoot, "", getOptions, []string{resolvedContainerPath}, writer)
+	}, nil
+}
+
+// getIDMappingsAndPair returns the ID mappings for the container and the host
+// ID pair.
+func getIDMappingsAndPair(container *libpod.Container, containerMount string) (*storage.IDMappingOptions, *idtools.IDPair, error) {
+	user, err := getContainerUser(container, containerMount)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	idMappingOpts, err := container.IDMappings()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	hostUID, hostGID, err := util.GetHostIDs(idtoolsToRuntimeSpec(idMappingOpts.UIDMap), idtoolsToRuntimeSpec(idMappingOpts.GIDMap), user.UID, user.GID)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	idPair := idtools.IDPair{UID: int(hostUID), GID: int(hostGID)}
+	return &idMappingOpts, &idPair, nil
+}
+
+// getContainerUser returns the specs.User of the container.
+func getContainerUser(container *libpod.Container, mountPoint string) (specs.User, error) {
+	userspec := container.Config().User
+
+	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
+}
+
+// idtoolsToRuntimeSpec converts idtools ID mapping to the one of the runtime spec.
+func idtoolsToRuntimeSpec(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
+}