podman image prune -- implement all flag

we now, by default, only prune dangling images.  if --all is passed, we
prune dangling images AND images that do not have an associated containers.

also went ahead and enabled the podman-remote image prune side of things.

Fixes: #2192

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

MH: Removed dependence on remote-client adapter work to limit scale of changes

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

8 files changed, 76 insertions, 40 deletions

diff --git a/API.md b/API.md
index 0cbdffea4..e4576850b 100755
--- a/API.md
+++ b/API.md
@@ -57,7 +57,7 @@ in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in
 
 [func ImageExists(name: string) int](#ImageExists)
 
-[func ImagesPrune() []string](#ImagesPrune)
+[func ImagesPrune(all: bool) []string](#ImagesPrune)
 
 [func ImportImage(source: string, reference: string, message: string, changes: []string) string](#ImportImage)
 
@@ -548,7 +548,7 @@ $ varlink call -m unix:/run/podman/io.podman/io.podman.ImageExists '{"name": "im
 ### <a name="ImagesPrune"></a>func ImagesPrune
 <div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
 
-method ImagesPrune() [[]string](#[]string)</div>
+method ImagesPrune(all: [bool](https://godoc.org/builtin#bool)) [[]string](#[]string)</div>
 ImagesPrune removes all unused images from the local store.  Upon successful pruning,
 the IDs of the removed images are returned.
 ### <a name="ImportImage"></a>func ImportImage
diff --git a/cmd/podman/images_prune.go b/cmd/podman/images_prune.go
index 06879e02d..7310137e7 100644
--- a/cmd/podman/images_prune.go
+++ b/cmd/podman/images_prune.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+
 	"github.com/containers/libpod/cmd/podman/libpodruntime"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
@@ -13,13 +14,19 @@ var (
 
 	Removes all unnamed images from local storage
 `
-
+	pruneImageFlags = []cli.Flag{
+		cli.BoolFlag{
+			Name:  "all, a",
+			Usage: "remove all unused images, not just dangling ones",
+		},
+	}
 	pruneImagesCommand = cli.Command{
 		Name:         "prune",
 		Usage:        "Remove unused images",
 		Description:  pruneImagesDescription,
 		Action:       pruneImagesCmd,
 		OnUsageError: usageErrorHandler,
+		Flags:        pruneImageFlags,
 	}
 )
 
@@ -30,16 +37,13 @@ func pruneImagesCmd(c *cli.Context) error {
 	}
 	defer runtime.Shutdown(false)
 
-	pruneImages, err := runtime.ImageRuntime().GetPruneImages()
-	if err != nil {
-		return err
-	}
-
-	for _, i := range pruneImages {
-		if err := i.Remove(true); err != nil {
-			return errors.Wrapf(err, "failed to remove %s", i.ID())
+	// Call prune; if any cids are returned, print them and then
+	// return err in case an error also came up
+	pruneCids, err := runtime.ImageRuntime().PruneImages(c.Bool("all"))
+	if len(pruneCids) > 0 {
+		for _, cid := range pruneCids {
+			fmt.Println(cid)
 		}
-		fmt.Println(i.ID())
 	}
-	return nil
+	return err
 }
diff --git a/cmd/podman/varlink/io.podman.varlink b/cmd/podman/varlink/io.podman.varlink
index 7cd6c16b2..6f3bf34a2 100644
--- a/cmd/podman/varlink/io.podman.varlink
+++ b/cmd/podman/varlink/io.podman.varlink
@@ -1017,7 +1017,7 @@ method  UnmountContainer(name: string, force: bool) -> ()
 
 # ImagesPrune removes all unused images from the local store.  Upon successful pruning,
 # the IDs of the removed images are returned.
-method ImagesPrune() -> (pruned: []string)
+method ImagesPrune(all: bool) -> (pruned: []string)
 
 # This function is not implemented yet.
 method ListContainerPorts(name: string) -> (notimplemented: NotImplemented)
diff --git a/completions/bash/podman b/completions/bash/podman
index 6333dfdf2..410180638 100644
--- a/completions/bash/podman
+++ b/completions/bash/podman
@@ -2453,6 +2453,8 @@ _podman_images_prune() {
     "
 
     local boolean_options="
+    -a
+    --all
      -h
 	 --help
   "
diff --git a/docs/podman-image-prune.1.md b/docs/podman-image-prune.1.md
index db76b26e0..df912c380 100644
--- a/docs/podman-image-prune.1.md
+++ b/docs/podman-image-prune.1.md
@@ -6,23 +6,38 @@ podman-image-prune - Remove all unused images
 
 # SYNOPSIS
 **podman image prune**
+[**-a**|**--all**]
 [**-h**|**--help**]
 
 # DESCRIPTION
-**podman image prune** removes all unused images from local storage. An unused image
-is defined as an image that does not have any containers based on it.
+**podman image prune** removes all dangling images from local storage. With the `all` option,
+you can delete all unused images.  Unused images are dangling images as well as any image that
+does not have any containers based on it.
+
+## OPTIONS
+**--all, -a**
+
+Remove dangling images and images that have no associated containers.
 
 ## Examples ##
 
-Remove all unused images from local storage
+Remove all dangling images from local storage
 ```
 $ sudo podman image prune
 f3e20dc537fb04cb51672a5cb6fdf2292e61d411315549391a0d1f64e4e3097e
 324a7a3b2e0135f4226ffdd473e4099fd9e477a74230cdc35de69e84c0f9d907
+```
+
+Remove all unused images from local storage
+```
+$ sudo podman image prune -a
+f3e20dc537fb04cb51672a5cb6fdf2292e61d411315549391a0d1f64e4e3097e
+324a7a3b2e0135f4226ffdd473e4099fd9e477a74230cdc35de69e84c0f9d907
 6125002719feb1ddf3030acab1df6156da7ce0e78e571e9b6e9c250424d6220c
 91e732da5657264c6f4641b8d0c4001c218ae6c1adb9dcef33ad00cafd37d8b6
 e4e5109420323221f170627c138817770fb64832da7d8fe2babd863148287fca
 77a57fa8285e9656dbb7b23d9efa837a106957409ddd702f995605af27a45ebe
+
 ```
 
 ## SEE ALSO
diff --git a/libpod/image/prune.go b/libpod/image/prune.go
index 6a1f160d5..8602c222c 100644
--- a/libpod/image/prune.go
+++ b/libpod/image/prune.go
@@ -1,9 +1,11 @@
 package image
 
+import "github.com/pkg/errors"
+
 // GetPruneImages returns a slice of images that have no names/unused
-func (ir *Runtime) GetPruneImages() ([]*Image, error) {
+func (ir *Runtime) GetPruneImages(all bool) ([]*Image, error) {
 	var (
-		unamedImages []*Image
+		pruneImages []*Image
 	)
 	allImages, err := ir.GetImages()
 	if err != nil {
@@ -11,16 +13,35 @@ func (ir *Runtime) GetPruneImages() ([]*Image, error) {
 	}
 	for _, i := range allImages {
 		if len(i.Names()) == 0 {
-			unamedImages = append(unamedImages, i)
+			pruneImages = append(pruneImages, i)
 			continue
 		}
-		containers, err := i.Containers()
-		if err != nil {
-			return nil, err
+		if all {
+			containers, err := i.Containers()
+			if err != nil {
+				return nil, err
+			}
+			if len(containers) < 1 {
+				pruneImages = append(pruneImages, i)
+			}
 		}
-		if len(containers) < 1 {
-			unamedImages = append(unamedImages, i)
+	}
+	return pruneImages, nil
+}
+
+// PruneImages prunes dangling and optionally all unused images from the local
+// image store
+func (ir *Runtime) PruneImages(all bool) ([]string, error) {
+	var prunedCids []string
+	pruneImages, err := ir.GetPruneImages(all)
+	if err != nil {
+		return nil, errors.Wrap(err, "unable to get images to prune")
+	}
+	for _, p := range pruneImages {
+		if err := p.Remove(true); err != nil {
+			return nil, errors.Wrap(err, "failed to prune image")
 		}
+		prunedCids = append(prunedCids, p.ID())
 	}
-	return unamedImages, nil
+	return prunedCids, nil
 }
diff --git a/pkg/varlinkapi/images.go b/pkg/varlinkapi/images.go
index 4a4f20031..cfcdde6ef 100644
--- a/pkg/varlinkapi/images.go
+++ b/pkg/varlinkapi/images.go
@@ -622,19 +622,10 @@ func (i *LibpodAPI) ContainerRunlabel(call iopodman.VarlinkCall, input iopodman.
 }
 
 // ImagesPrune ....
-func (i *LibpodAPI) ImagesPrune(call iopodman.VarlinkCall) error {
-	var (
-		pruned []string
-	)
-	pruneImages, err := i.Runtime.ImageRuntime().GetPruneImages()
+func (i *LibpodAPI) ImagesPrune(call iopodman.VarlinkCall, all bool) error {
+	prunedImages, err := i.Runtime.ImageRuntime().PruneImages(all)
 	if err != nil {
-		return err
-	}
-	for _, i := range pruneImages {
-		if err := i.Remove(true); err != nil {
-			return call.ReplyErrorOccurred(err.Error())
-		}
-		pruned = append(pruned, i.ID())
+		return call.ReplyErrorOccurred(err.Error())
 	}
-	return call.ReplyImagesPrune(pruned)
+	return call.ReplyImagesPrune(prunedImages)
 }
diff --git a/test/e2e/prune_test.go b/test/e2e/prune_test.go
index 6679a676c..81fb82b20 100644
--- a/test/e2e/prune_test.go
+++ b/test/e2e/prune_test.go
@@ -39,6 +39,7 @@ var _ = Describe("Podman rm", func() {
 	})
 
 	It("podman container prune containers", func() {
+		SkipIfRemote()
 		top := podmanTest.RunTopContainer("")
 		top.WaitWithDefaultTimeout()
 		Expect(top.ExitCode()).To(Equal(0))
@@ -55,6 +56,7 @@ var _ = Describe("Podman rm", func() {
 	})
 
 	It("podman image prune none images", func() {
+		SkipIfRemote()
 		podmanTest.BuildImage(pruneImage, "alpine_bash:latest", "true")
 
 		none := podmanTest.Podman([]string{"images", "-a"})
@@ -72,10 +74,11 @@ var _ = Describe("Podman rm", func() {
 		Expect(none.ExitCode()).To(Equal(0))
 		hasNoneAfter, _ := after.GrepString("<none>")
 		Expect(hasNoneAfter).To(BeFalse())
+		Expect(len(after.OutputToStringArray()) > 1).To(BeTrue())
 	})
 
 	It("podman image prune unused images", func() {
-		prune := podmanTest.Podman([]string{"image", "prune"})
+		prune := podmanTest.Podman([]string{"image", "prune", "-a"})
 		prune.WaitWithDefaultTimeout()
 		Expect(prune.ExitCode()).To(Equal(0))