pkg/copy: add parsing API

Add an API for parsing user input into a possibly specified container
and path.  This allows for sharing the parsing code between the local
and the remote client (and bindings) in the future.

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

3 files changed, 88 insertions, 36 deletions

diff --git a/pkg/copy/parse.go b/pkg/copy/parse.go
new file mode 100644
index 000000000..39e0e1547
--- /dev/null
+++ b/pkg/copy/parse.go
@@ -0,0 +1,61 @@
+package copy
+
+import (
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+// ParseSourceAndDestination parses the source and destination input into a
+// possibly specified container and path.  The input format is described in
+// podman-cp(1) as "[nameOrID:]path".  Colons in paths are supported as long
+// they start with a dot or slash.
+//
+// It returns, in order, the source container and path, followed by the
+// destination container and path, and an error.  Note that exactly one
+// container must be specified.
+func ParseSourceAndDestination(source, destination string) (string, string, string, string, error) {
+	sourceContainer, sourcePath := parseUserInput(source)
+	destContainer, destPath := parseUserInput(destination)
+
+	numContainers := 0
+	if len(sourceContainer) > 0 {
+		numContainers++
+	}
+	if len(destContainer) > 0 {
+		numContainers++
+	}
+
+	if numContainers != 1 {
+		return "", "", "", "", errors.Errorf("invalid arguments %q, %q: exactly 1 container expected but %d specified", source, destination, numContainers)
+	}
+
+	if len(sourcePath) == 0 || len(destPath) == 0 {
+		return "", "", "", "", errors.Errorf("invalid arguments %q, %q: you must specify paths", source, destination)
+	}
+
+	return sourceContainer, sourcePath, destContainer, destPath, nil
+}
+
+// parseUserInput parses the input string and returns, if specified, the name
+// or ID of the container and the path.  The input format is described in
+// podman-cp(1) as "[nameOrID:]path".  Colons in paths are supported as long
+// they start with a dot or slash.
+func parseUserInput(input string) (container string, path string) {
+	if len(input) == 0 {
+		return
+	}
+	path = input
+
+	// If the input starts with a dot or slash, it cannot refer to a
+	// container.
+	if input[0] == '.' || input[0] == '/' {
+		return
+	}
+
+	if spl := strings.SplitN(path, ":", 2); len(spl) == 2 {
+		container = spl[0]
+		path = spl[1]
+	}
+	return
+}
diff --git a/pkg/domain/infra/abi/cp.go b/pkg/domain/infra/abi/cp.go
index 9409df743..7cc3005c1 100644
--- a/pkg/domain/infra/abi/cp.go
+++ b/pkg/domain/infra/abi/cp.go
@@ -2,46 +2,53 @@ package abi
 
 import (
 	"context"
-	"strings"
 
 	"github.com/containers/podman/v2/libpod"
 	"github.com/containers/podman/v2/pkg/copy"
 	"github.com/containers/podman/v2/pkg/domain/entities"
-	"github.com/pkg/errors"
 )
 
 func (ic *ContainerEngine) ContainerCp(ctx context.Context, source, dest string, options entities.ContainerCpOptions) error {
-	srcCtr, srcPath := parsePath(ic.Libpod, source)
-	destCtr, destPath := parsePath(ic.Libpod, dest)
-
-	if srcCtr != nil && destCtr != nil {
-		return errors.Errorf("invalid arguments %q, %q: you must use just one container", source, dest)
+	// Parse user input.
+	sourceContainerStr, sourcePath, destContainerStr, destPath, err := copy.ParseSourceAndDestination(source, dest)
+	if err != nil {
+		return err
 	}
-	if srcCtr == nil && destCtr == nil {
-		return errors.Errorf("invalid arguments %q, %q: you must specify one container", source, dest)
+
+	// Look up containers.
+	var sourceContainer, destContainer *libpod.Container
+	if len(sourceContainerStr) > 0 {
+		sourceContainer, err = ic.Libpod.LookupContainer(sourceContainerStr)
+		if err != nil {
+			return err
+		}
 	}
-	if len(srcPath) == 0 || len(destPath) == 0 {
-		return errors.Errorf("invalid arguments %q, %q: you must specify paths", source, dest)
+	if len(destContainerStr) > 0 {
+		destContainer, err = ic.Libpod.LookupContainer(destContainerStr)
+		if err != nil {
+			return err
+		}
 	}
 
 	var sourceItem, destinationItem copy.CopyItem
-	var err error
-	// Copy from the container to the host.
-	if srcCtr != nil {
-		sourceItem, err = copy.CopyItemForContainer(srcCtr, srcPath, options.Pause, true)
+
+	// Source ... container OR host.
+	if sourceContainer != nil {
+		sourceItem, err = copy.CopyItemForContainer(sourceContainer, sourcePath, options.Pause, true)
 		defer sourceItem.CleanUp()
 		if err != nil {
 			return err
 		}
 	} else {
-		sourceItem, err = copy.CopyItemForHost(srcPath, true)
+		sourceItem, err = copy.CopyItemForHost(sourcePath, true)
 		if err != nil {
 			return err
 		}
 	}
 
-	if destCtr != nil {
-		destinationItem, err = copy.CopyItemForContainer(destCtr, destPath, options.Pause, false)
+	// Destination ... container OR host.
+	if destContainer != nil {
+		destinationItem, err = copy.CopyItemForContainer(destContainer, destPath, options.Pause, false)
 		defer destinationItem.CleanUp()
 		if err != nil {
 			return err
@@ -57,20 +64,3 @@ func (ic *ContainerEngine) ContainerCp(ctx context.Context, source, dest string,
 	// Copy from the host to the container.
 	return copy.Copy(&sourceItem, &destinationItem, options.Extract)
 }
-
-func parsePath(runtime *libpod.Runtime, path string) (*libpod.Container, string) {
-	if len(path) == 0 {
-		return nil, ""
-	}
-	if path[0] == '.' || path[0] == '/' { // A path cannot point to a container.
-		return nil, path
-	}
-	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
-}
diff --git a/pkg/domain/infra/tunnel/containers.go b/pkg/domain/infra/tunnel/containers.go
index 3584668c7..e65fef0a4 100644
--- a/pkg/domain/infra/tunnel/containers.go
+++ b/pkg/domain/infra/tunnel/containers.go
@@ -732,7 +732,8 @@ func (ic *ContainerEngine) ContainerPort(ctx context.Context, nameOrID string, o
 }
 
 func (ic *ContainerEngine) ContainerCp(ctx context.Context, source, dest string, options entities.ContainerCpOptions) error {
-	return errors.New("not implemented")
+	return nil
+	//	return containers.Copy(ic.ClientCxt, source, dest, options)
 }
 
 // Shutdown Libpod engine