Add `untag` sub-command

Podman now supports untagging images via the `untag` sub-command for the
root and `image` commands. Testing and documentation has been added as
well.

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

5 files changed, 79 insertions, 0 deletions

diff --git a/cmd/podman/cliconfig/config.go b/cmd/podman/cliconfig/config.go
index 282d90d0b..0e4315411 100644
--- a/cmd/podman/cliconfig/config.go
+++ b/cmd/podman/cliconfig/config.go
@@ -681,3 +681,7 @@ type SystemDfValues struct {
 	Verbose bool
 	Format  string
 }
+
+type UntagValues struct {
+	PodmanCommand
+}
diff --git a/cmd/podman/image.go b/cmd/podman/image.go
index 66c141686..ce576ff4b 100644
--- a/cmd/podman/image.go
+++ b/cmd/podman/image.go
@@ -74,6 +74,7 @@ var imageSubCommands = []*cobra.Command{
 	_saveCommand,
 	_tagCommand,
 	_treeCommand,
+	_untagCommand,
 }
 
 func init() {
diff --git a/cmd/podman/main.go b/cmd/podman/main.go
index 344170ddd..c727eea85 100644
--- a/cmd/podman/main.go
+++ b/cmd/podman/main.go
@@ -68,6 +68,7 @@ var mainCommands = []*cobra.Command{
 	imageCommand.Command,
 	_startCommand,
 	systemCommand.Command,
+	_untagCommand,
 }
 
 var rootCmd = &cobra.Command{
diff --git a/cmd/podman/untag.go b/cmd/podman/untag.go
new file mode 100644
index 000000000..9ff62b808
--- /dev/null
+++ b/cmd/podman/untag.go
@@ -0,0 +1,67 @@
+package main
+
+import (
+	"github.com/containers/libpod/cmd/podman/cliconfig"
+	"github.com/containers/libpod/pkg/adapter"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+var (
+	untagCommand cliconfig.UntagValues
+
+	_untagCommand = &cobra.Command{
+		Use:   "untag [flags] IMAGE [NAME...]",
+		Short: "Remove a name from a local image",
+		Long:  "Removes one or more names from a locally-stored image.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			untagCommand.InputArgs = args
+			untagCommand.GlobalFlags = MainGlobalOpts
+			untagCommand.Remote = remoteclient
+			return untag(&untagCommand)
+		},
+		Example: `podman untag 0e3bbc2
+  podman untag imageID:latest otherImageName:latest
+  podman untag httpd myregistryhost:5000/fedora/httpd:v2`,
+	}
+)
+
+func init() {
+	untagCommand.Command = _untagCommand
+	untagCommand.SetHelpTemplate(HelpTemplate())
+	untagCommand.SetUsageTemplate(UsageTemplate())
+}
+
+func untag(c *cliconfig.UntagValues) error {
+	args := c.InputArgs
+
+	if len(args) == 0 {
+		return errors.Errorf("at least one image name needs to be specified")
+	}
+
+	runtime, err := adapter.GetRuntime(getContext(), &c.PodmanCommand)
+	if err != nil {
+		return errors.Wrapf(err, "could not create runtime")
+	}
+	defer runtime.DeferredShutdown(false)
+
+	newImage, err := runtime.NewImageFromLocal(args[0])
+	if err != nil {
+		return err
+	}
+
+	tags := args[1:]
+	if len(args) == 1 {
+		// Remove all tags if not explicitly specified
+		tags = newImage.Names()
+	}
+	logrus.Debugf("Tags to be removed: %v", tags)
+
+	for _, tag := range tags {
+		if err := newImage.UntagImage(tag); err != nil {
+			return errors.Wrapf(err, "removing %q from %q", tag, newImage.InputName)
+		}
+	}
+	return nil
+}
diff --git a/cmd/podman/varlink/io.podman.varlink b/cmd/podman/varlink/io.podman.varlink
index 1bacd2de6..e1f28d847 100644
--- a/cmd/podman/varlink/io.podman.varlink
+++ b/cmd/podman/varlink/io.podman.varlink
@@ -860,6 +860,12 @@ method PushImage(name: string, tag: string, compress: bool, format: string, remo
 # be found, an [ImageNotFound](#ImageNotFound) error will be returned; otherwise, the ID of the image is returned on success.
 method TagImage(name: string, tagged: string) -> (image: string)
 
+# UntagImage takes the name or ID of an image in local storage as well as the
+# tag name to be removed.  If the image cannot be found, an
+# [ImageNotFound](#ImageNotFound) error will be returned; otherwise, the ID of
+# the image is returned on success.
+method UntagImage(name: string, tag: string) -> (image: string)
+
 # RemoveImage takes the name or ID of an image as well as a boolean that determines if containers using that image
 # should be deleted.  If the image cannot be found, an [ImageNotFound](#ImageNotFound) error will be returned.  The
 # ID of the removed image is returned when complete.  See also [DeleteUnusedImages](DeleteUnusedImages).