podmanv2 export

add ability to export a container to a tarball

Signed-off-by: Brent Baude <bbaude@redhat.com>

8 files changed, 193 insertions, 0 deletions

diff --git a/cmd/podmanV2/containers/export.go b/cmd/podmanV2/containers/export.go
new file mode 100644
index 000000000..b93b60878
--- /dev/null
+++ b/cmd/podmanV2/containers/export.go
@@ -0,0 +1,57 @@
+package containers
+
+import (
+	"context"
+	"os"
+
+	"github.com/containers/libpod/cmd/podmanV2/parse"
+	"github.com/containers/libpod/cmd/podmanV2/registry"
+	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+var (
+	exportDescription = "Exports container's filesystem contents as a tar archive" +
+		" and saves it on the local machine."
+
+	exportCommand = &cobra.Command{
+		Use:               "export [flags] CONTAINER",
+		Short:             "Export container's filesystem contents as a tar archive",
+		Long:              exportDescription,
+		PersistentPreRunE: preRunE,
+		RunE:              export,
+		Args:              cobra.ExactArgs(1),
+		Example: `podman export ctrID > myCtr.tar
+  podman export --output="myCtr.tar" ctrID`,
+	}
+)
+
+var (
+	exportOpts entities.ContainerExportOptions
+)
+
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
+		Command: exportCommand,
+	})
+	exportCommand.SetHelpTemplate(registry.HelpTemplate())
+	exportCommand.SetUsageTemplate(registry.UsageTemplate())
+	flags := exportCommand.Flags()
+	flags.StringVarP(&exportOpts.Output, "output", "o", "", "Write to a specified file (default: stdout, which must be redirected)")
+}
+
+func export(cmd *cobra.Command, args []string) error {
+	if len(exportOpts.Output) == 0 {
+		file := os.Stdout
+		if terminal.IsTerminal(int(file.Fd())) {
+			return errors.Errorf("refusing to export to terminal. Use -o flag or redirect")
+		}
+		exportOpts.Output = "/dev/stdout"
+	} else if err := parse.ValidateFileName(exportOpts.Output); err != nil {
+		return err
+	}
+	return registry.ContainerEngine().ContainerExport(context.Background(), args[0], exportOpts)
+}
diff --git a/pkg/api/handlers/compat/containers_export.go b/pkg/api/handlers/compat/containers_export.go
new file mode 100644
index 000000000..37b9fbf2b
--- /dev/null
+++ b/pkg/api/handlers/compat/containers_export.go
@@ -0,0 +1,42 @@
+package compat
+
+import (
+	"io/ioutil"
+	"net/http"
+	"os"
+
+	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/pkg/api/handlers/utils"
+	"github.com/pkg/errors"
+)
+
+func ExportContainer(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	name := utils.GetName(r)
+	con, err := runtime.LookupContainer(name)
+	if err != nil {
+		utils.ContainerNotFound(w, name, err)
+		return
+	}
+	tmpfile, err := ioutil.TempFile("", "api.tar")
+	if err != nil {
+		utils.Error(w, "unable to create tarball tempfile", http.StatusInternalServerError, errors.Wrap(err, "unable to create tempfile"))
+		return
+	}
+	defer os.Remove(tmpfile.Name())
+	if err := tmpfile.Close(); err != nil {
+		utils.Error(w, "unable to close tempfile", http.StatusInternalServerError, errors.Wrap(err, "unable to close tempfile"))
+		return
+	}
+	if err := con.Export(tmpfile.Name()); err != nil {
+		utils.Error(w, "failed to save the image", http.StatusInternalServerError, errors.Wrap(err, "failed to save image"))
+		return
+	}
+	rdr, err := os.Open(tmpfile.Name())
+	if err != nil {
+		utils.Error(w, "failed to read temp tarball", http.StatusInternalServerError, errors.Wrap(err, "failed to read the exported tarfile"))
+		return
+	}
+	defer rdr.Close()
+	utils.WriteResponse(w, http.StatusOK, rdr)
+}
diff --git a/pkg/api/server/register_containers.go b/pkg/api/server/register_containers.go
index 08834ff01..145c054c0 100644
--- a/pkg/api/server/register_containers.go
+++ b/pkg/api/server/register_containers.go
@@ -587,6 +587,29 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	r.HandleFunc(VersionedPath("/containers/{name}/resize"), s.APIHandler(compat.ResizeContainer)).Methods(http.MethodPost)
 	// Added non version path to URI to support docker non versioned paths
 	r.HandleFunc("/containers/{name}/resize", s.APIHandler(compat.ResizeContainer)).Methods(http.MethodPost)
+	// swagger:operation GET /containers/{name}/export compat exportContainer
+	// ---
+	// tags:
+	//   - containers (compat)
+	// summary: Export a container
+	// description: Export the contents of a container as a tarball.
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or ID of the container
+	// produces:
+	// - application/json
+	// responses:
+	//   200:
+	//     description: tarball is returned in body
+	//   404:
+	//     $ref: "#/responses/NoSuchContainer"
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/containers/{name}/export"), s.APIHandler(compat.ExportContainer)).Methods(http.MethodGet)
+	r.HandleFunc("/containers/{name}/export", s.APIHandler(compat.ExportContainer)).Methods(http.MethodGet)
 
 	/*
 		libpod endpoints
@@ -1237,5 +1260,27 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/containers/{name}/resize"), s.APIHandler(compat.ResizeContainer)).Methods(http.MethodPost)
+	// swagger:operation GET /libpod/containers/{name}/export libpod libpodExportContainer
+	// ---
+	// tags:
+	//   - containers
+	// summary: Export a container
+	// description: Export the contents of a container as a tarball.
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or ID of the container
+	// produces:
+	// - application/json
+	// responses:
+	//   200:
+	//     description: tarball is returned in body
+	//   404:
+	//     $ref: "#/responses/NoSuchContainer"
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/containers/{name}/export"), s.APIHandler(compat.ExportContainer)).Methods(http.MethodGet)
 	return nil
 }
diff --git a/pkg/bindings/containers/containers.go b/pkg/bindings/containers/containers.go
index bad1294f4..49a2dfd58 100644
--- a/pkg/bindings/containers/containers.go
+++ b/pkg/bindings/containers/containers.go
@@ -2,6 +2,7 @@ package containers
 
 import (
 	"context"
+	"io"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -296,3 +297,22 @@ func Stop(ctx context.Context, nameOrID string, timeout *uint) error {
 	}
 	return response.Process(nil)
 }
+
+// Export creates a tarball of the given name or ID of a container.  It
+// requires an io.Writer be provided to write the tarball.
+func Export(ctx context.Context, nameOrID string, w io.Writer) error {
+	params := url.Values{}
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return err
+	}
+	response, err := conn.DoRequest(nil, http.MethodGet, "/containers/%s/export", params, nameOrID)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode/100 == 2 {
+		_, err = io.Copy(w, response.Body)
+		return err
+	}
+	return response.Process(nil)
+}
diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go
index b7f1cd812..d51124f55 100644
--- a/pkg/domain/entities/containers.go
+++ b/pkg/domain/entities/containers.go
@@ -117,3 +117,7 @@ type CommitOptions struct {
 type CommitReport struct {
 	Id string
 }
+
+type ContainerExportOptions struct {
+	Output string
+}
diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index c5f46ccfc..a122857cd 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -10,6 +10,7 @@ type ContainerEngine interface {
 	ContainerCommit(ctx context.Context, nameOrId string, options CommitOptions) (*CommitReport, error)
 	ContainerExists(ctx context.Context, nameOrId string) (*BoolReport, error)
 	ContainerInspect(ctx context.Context, namesOrIds []string, options InspectOptions) ([]*ContainerInspectReport, error)
+	ContainerExport(ctx context.Context, nameOrId string, options ContainerExportOptions) error
 	ContainerKill(ctx context.Context, namesOrIds []string, options KillOptions) ([]*KillReport, error)
 	ContainerPause(ctx context.Context, namesOrIds []string, options PauseUnPauseOptions) ([]*PauseUnpauseReport, error)
 	ContainerRestart(ctx context.Context, namesOrIds []string, options RestartOptions) ([]*RestartReport, error)
diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go
index 172c7d1a3..d4c5ac311 100644
--- a/pkg/domain/infra/abi/containers.go
+++ b/pkg/domain/infra/abi/containers.go
@@ -325,3 +325,11 @@ func (ic *ContainerEngine) ContainerCommit(ctx context.Context, nameOrId string,
 	}
 	return &entities.CommitReport{Id: newImage.ID()}, nil
 }
+
+func (ic *ContainerEngine) ContainerExport(ctx context.Context, nameOrId string, options entities.ContainerExportOptions) error {
+	ctr, err := ic.Libpod.LookupContainer(nameOrId)
+	if err != nil {
+		return err
+	}
+	return ctr.Export(options.Output)
+}
diff --git a/pkg/domain/infra/tunnel/containers.go b/pkg/domain/infra/tunnel/containers.go
index c1bade4ba..8885ae7c7 100644
--- a/pkg/domain/infra/tunnel/containers.go
+++ b/pkg/domain/infra/tunnel/containers.go
@@ -2,6 +2,8 @@ package tunnel
 
 import (
 	"context"
+	"io"
+	"os"
 
 	"github.com/containers/image/v5/docker/reference"
 
@@ -210,3 +212,17 @@ func (ic *ContainerEngine) ContainerCommit(ctx context.Context, nameOrId string,
 	}
 	return &entities.CommitReport{Id: response.ID}, nil
 }
+
+func (ic *ContainerEngine) ContainerExport(ctx context.Context, nameOrId string, options entities.ContainerExportOptions) error {
+	var (
+		err error
+		w   io.Writer
+	)
+	if len(options.Output) > 0 {
+		w, err = os.Create(options.Output)
+		if err != nil {
+			return err
+		}
+	}
+	return containers.Export(ic.ClientCxt, nameOrId, w)
+}