Add system test for shell completion

There exists a unit test to ensure that shell completion functions are
defined. However there was no check about the quality of the provided
shell completions. Lets change that.

The idea is to create a general test that makes sure we are suggesting
containers,pods,images... for the correct commands. This works by
reading the command use line and checking for each arg if we provide
the correct suggestions for this arg.

It includes the following tests:
- flag suggestions if [options] is set
- container, pod, image, network, volume, registry completion
- path completion for the appropriate arg KEYWORDS (`PATH`,`CONTEXT`,etc.)
- no completion if there are no args
- completion for more than one arg if it ends with `...]`

The test does not cover completion values for flags and not every arg KEYWORD
is supported. This is still a huge improvement and covers most use cases.

This test spotted several inconsistencies between the completion and the
command use line. All of them have been adjusted to make the test pass.

The biggest advantage is that the completions always match the latest
command changes. So if someone changes the arguments for a command this
ensures that the completions must be adjusted.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

5 files changed, 8 insertions, 6 deletions

diff --git a/cmd/podman/images/build.go b/cmd/podman/images/build.go
index 739e1c265..48b355ecd 100644
--- a/cmd/podman/images/build.go
+++ b/cmd/podman/images/build.go
@@ -11,6 +11,7 @@ import (
 	"github.com/containers/buildah/pkg/parse"
 	"github.com/containers/common/pkg/completion"
 	"github.com/containers/common/pkg/config"
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/cmd/podman/utils"
 	"github.com/containers/podman/v2/pkg/domain/entities"
@@ -44,7 +45,7 @@ var (
 		Long:              buildDescription,
 		Args:              cobra.MaximumNArgs(1),
 		RunE:              build,
-		ValidArgsFunction: completion.AutocompleteDefault,
+		ValidArgsFunction: common.AutocompleteDefaultOneArg,
 		Example: `podman build .
   podman build --creds=username:password -t imageName -f Containerfile.simple .
   podman build --layers --force-rm --tag imageName .`,
diff --git a/cmd/podman/images/import.go b/cmd/podman/images/import.go
index f38ab3b19..ac59935ad 100644
--- a/cmd/podman/images/import.go
+++ b/cmd/podman/images/import.go
@@ -25,18 +25,19 @@ var (
 		Short:             "Import a tarball to create a filesystem image",
 		Long:              importDescription,
 		RunE:              importCon,
-		ValidArgsFunction: completion.AutocompleteDefault,
+		Args:              cobra.RangeArgs(1, 2),
+		ValidArgsFunction: common.AutocompleteDefaultOneArg,
 		Example: `podman import http://example.com/ctr.tar url-image
   cat ctr.tar | podman -q import --message "importing the ctr.tar tarball" - image-imported
   cat ctr.tar | podman import -`,
 	}
 
 	imageImportCommand = &cobra.Command{
-		Args:              cobra.MinimumNArgs(1),
 		Use:               importCommand.Use,
 		Short:             importCommand.Short,
 		Long:              importCommand.Long,
 		RunE:              importCommand.RunE,
+		Args:              importCommand.Args,
 		ValidArgsFunction: importCommand.ValidArgsFunction,
 		Example: `podman image import http://example.com/ctr.tar url-image
   cat ctr.tar | podman -q image import --message "importing the ctr.tar tarball" - image-imported
diff --git a/cmd/podman/images/push.go b/cmd/podman/images/push.go
index 447b02fbe..d82083cd8 100644
--- a/cmd/podman/images/push.go
+++ b/cmd/podman/images/push.go
@@ -29,7 +29,7 @@ var (
 
 	// Command: podman push
 	pushCmd = &cobra.Command{
-		Use:               "push [options] SOURCE [DESTINATION]",
+		Use:               "push [options] IMAGE [DESTINATION]",
 		Short:             "Push an image to a specified destination",
 		Long:              pushDescription,
 		RunE:              imagePush,
diff --git a/cmd/podman/images/save.go b/cmd/podman/images/save.go
index 9ef2d0c91..3a35c4fad 100644
--- a/cmd/podman/images/save.go
+++ b/cmd/podman/images/save.go
@@ -43,7 +43,7 @@ var (
 			}
 			return nil
 		},
-		ValidArgsFunction: completion.AutocompleteNone,
+		ValidArgsFunction: common.AutocompleteImages,
 		Example: `podman save --quiet -o myimage.tar imageID
   podman save --format docker-dir -o ubuntu-dir ubuntu
   podman save > alpine-all.tar alpine:latest`,
diff --git a/cmd/podman/images/untag.go b/cmd/podman/images/untag.go
index 17dc21203..3cf62713b 100644
--- a/cmd/podman/images/untag.go
+++ b/cmd/podman/images/untag.go
@@ -9,7 +9,7 @@ import (
 
 var (
 	untagCommand = &cobra.Command{
-		Use:                   "untag IMAGE [NAME...]",
+		Use:                   "untag IMAGE [IMAGE...]",
 		Short:                 "Remove a name from a local image",
 		Long:                  "Removes one or more names from a locally-stored image.",
 		RunE:                  untag,