Add shell completion with cobra

Allow automatic generation for shell completion scripts
with the internal cobra functions (requires v1.0.0+).

This should replace the handwritten completion scripts
and even adds support for fish. With this approach it is
less likley that completions and code are out of sync.

We can now create the scripts with
- podman completion bash
- podman completion zsh
- podman completion fish

To test the completion run:
source <(podman completion bash)

The same works for podman-remote and podman --remote and
it will complete your remote containers/images with
the correct endpoints values from --url/--connection.

The completion logic is written in go and provided by the
cobra library. The completion functions lives in
`cmd/podman/completion/completion.go`.

The unit test at cmd/podman/shell_completion_test.go checks
if each command and flag has an autocompletion function set.
This prevents that commands and flags have no shell completion set.

This commit does not replace the current autocompletion scripts.

Closes #6440

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

6 files changed, 126 insertions, 43 deletions

diff --git a/cmd/podman/manifest/add.go b/cmd/podman/manifest/add.go
index 4b85f4c2a..91bd423b8 100644
--- a/cmd/podman/manifest/add.go
+++ b/cmd/podman/manifest/add.go
@@ -5,7 +5,9 @@ import (
 	"fmt"
 
 	"github.com/containers/common/pkg/auth"
+	"github.com/containers/common/pkg/completion"
 	"github.com/containers/image/v5/types"
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/util"
@@ -25,10 +27,11 @@ type manifestAddOptsWrapper struct {
 var (
 	manifestAddOpts = manifestAddOptsWrapper{}
 	addCmd          = &cobra.Command{
-		Use:   "add [options] LIST LIST",
-		Short: "Add images to a manifest list or image index",
-		Long:  "Adds an image to a manifest list or image index.",
-		RunE:  add,
+		Use:               "add [options] LIST LIST",
+		Short:             "Add images to a manifest list or image index",
+		Long:              "Adds an image to a manifest list or image index.",
+		RunE:              add,
+		ValidArgsFunction: common.AutocompleteImages,
 		Example: `podman manifest add mylist:v1.11 image:v1.11-amd64
 		podman manifest add mylist:v1.11 transport:imageName`,
 		Args: cobra.ExactArgs(2),
@@ -43,17 +46,44 @@ func init() {
 	})
 	flags := addCmd.Flags()
 	flags.BoolVar(&manifestAddOpts.All, "all", false, "add all of the list's images if the image is a list")
-	flags.StringSliceVar(&manifestAddOpts.Annotation, "annotation", nil, "set an `annotation` for the specified image")
-	flags.StringVar(&manifestAddOpts.Arch, "arch", "", "override the `architecture` of the specified image")
-	flags.StringVar(&manifestAddOpts.Authfile, "authfile", auth.GetDefaultAuthFile(), "path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
-	flags.StringVar(&manifestAddOpts.CertDir, "cert-dir", "", "use certificates at the specified path to access the registry")
-	flags.StringVar(&manifestAddOpts.CredentialsCLI, "creds", "", "use `[username[:password]]` for accessing the registry")
-
-	flags.StringSliceVar(&manifestAddOpts.Features, "features", nil, "override the `features` of the specified image")
-	flags.StringVar(&manifestAddOpts.OS, "os", "", "override the `OS` of the specified image")
-	flags.StringVar(&manifestAddOpts.OSVersion, "os-version", "", "override the OS `version` of the specified image")
+
+	annotationFlagName := "annotation"
+	flags.StringSliceVar(&manifestAddOpts.Annotation, annotationFlagName, nil, "set an `annotation` for the specified image")
+	_ = addCmd.RegisterFlagCompletionFunc(annotationFlagName, completion.AutocompleteNone)
+
+	archFlagName := "arch"
+	flags.StringVar(&manifestAddOpts.Arch, archFlagName, "", "override the `architecture` of the specified image")
+	_ = addCmd.RegisterFlagCompletionFunc(archFlagName, completion.AutocompleteNone)
+
+	authfileFlagName := "authfile"
+	flags.StringVar(&manifestAddOpts.Authfile, authfileFlagName, auth.GetDefaultAuthFile(), "path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
+	_ = addCmd.RegisterFlagCompletionFunc(authfileFlagName, completion.AutocompleteDefault)
+
+	certDirFlagName := "cert-dir"
+	flags.StringVar(&manifestAddOpts.CertDir, certDirFlagName, "", "use certificates at the specified path to access the registry")
+	_ = addCmd.RegisterFlagCompletionFunc(certDirFlagName, completion.AutocompleteDefault)
+
+	credsFlagName := "creds"
+	flags.StringVar(&manifestAddOpts.CredentialsCLI, credsFlagName, "", "use `[username[:password]]` for accessing the registry")
+	_ = addCmd.RegisterFlagCompletionFunc(credsFlagName, completion.AutocompleteNone)
+
+	featuresFlagName := "features"
+	flags.StringSliceVar(&manifestAddOpts.Features, featuresFlagName, nil, "override the `features` of the specified image")
+	_ = addCmd.RegisterFlagCompletionFunc(featuresFlagName, completion.AutocompleteNone)
+
+	osFlagName := "os"
+	flags.StringVar(&manifestAddOpts.OS, osFlagName, "", "override the `OS` of the specified image")
+	_ = addCmd.RegisterFlagCompletionFunc(osFlagName, completion.AutocompleteNone)
+
+	osVersionFlagName := "os-version"
+	flags.StringVar(&manifestAddOpts.OSVersion, osVersionFlagName, "", "override the OS `version` of the specified image")
+	_ = addCmd.RegisterFlagCompletionFunc(osVersionFlagName, completion.AutocompleteNone)
+
 	flags.BoolVar(&manifestAddOpts.TLSVerifyCLI, "tls-verify", true, "require HTTPS and verify certificates when accessing the registry")
-	flags.StringVar(&manifestAddOpts.Variant, "variant", "", "override the `Variant` of the specified image")
+
+	variantFlagName := "variant"
+	flags.StringVar(&manifestAddOpts.Variant, variantFlagName, "", "override the `Variant` of the specified image")
+	_ = addCmd.RegisterFlagCompletionFunc(variantFlagName, completion.AutocompleteNone)
 
 	if registry.IsRemote() {
 		_ = flags.MarkHidden("cert-dir")
diff --git a/cmd/podman/manifest/annotate.go b/cmd/podman/manifest/annotate.go
index 861e94034..dab8c4da6 100644
--- a/cmd/podman/manifest/annotate.go
+++ b/cmd/podman/manifest/annotate.go
@@ -4,6 +4,8 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/containers/common/pkg/completion"
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/pkg/errors"
@@ -13,12 +15,13 @@ import (
 var (
 	manifestAnnotateOpts = entities.ManifestAnnotateOptions{}
 	annotateCmd          = &cobra.Command{
-		Use:     "annotate [options] LIST IMAGE",
-		Short:   "Add or update information about an entry in a manifest list or image index",
-		Long:    "Adds or updates information about an entry in a manifest list or image index.",
-		RunE:    annotate,
-		Example: `podman manifest annotate --annotation left=right mylist:v1.11 image:v1.11-amd64`,
-		Args:    cobra.ExactArgs(2),
+		Use:               "annotate [options] LIST IMAGE",
+		Short:             "Add or update information about an entry in a manifest list or image index",
+		Long:              "Adds or updates information about an entry in a manifest list or image index.",
+		RunE:              annotate,
+		Example:           `podman manifest annotate --annotation left=right mylist:v1.11 image:v1.11-amd64`,
+		Args:              cobra.ExactArgs(2),
+		ValidArgsFunction: common.AutocompleteImages,
 	}
 )
 
@@ -29,13 +32,34 @@ func init() {
 		Parent:  manifestCmd,
 	})
 	flags := annotateCmd.Flags()
-	flags.StringSliceVar(&manifestAnnotateOpts.Annotation, "annotation", nil, "set an `annotation` for the specified image")
-	flags.StringVar(&manifestAnnotateOpts.Arch, "arch", "", "override the `architecture` of the specified image")
-	flags.StringSliceVar(&manifestAnnotateOpts.Features, "features", nil, "override the `features` of the specified image")
-	flags.StringVar(&manifestAnnotateOpts.OS, "os", "", "override the `OS` of the specified image")
-	flags.StringSliceVar(&manifestAnnotateOpts.OSFeatures, "os-features", nil, "override the OS `features` of the specified image")
-	flags.StringVar(&manifestAnnotateOpts.OSVersion, "os-version", "", "override the OS `version` of the specified image")
-	flags.StringVar(&manifestAnnotateOpts.Variant, "variant", "", "override the `variant` of the specified image")
+
+	annotationFlagName := "annotation"
+	flags.StringSliceVar(&manifestAnnotateOpts.Annotation, annotationFlagName, nil, "set an `annotation` for the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(annotationFlagName, completion.AutocompleteNone)
+
+	archFlagName := "arch"
+	flags.StringVar(&manifestAnnotateOpts.Arch, archFlagName, "", "override the `architecture` of the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(archFlagName, completion.AutocompleteNone)
+
+	featuresFlagName := "features"
+	flags.StringSliceVar(&manifestAnnotateOpts.Features, featuresFlagName, nil, "override the `features` of the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(featuresFlagName, completion.AutocompleteNone)
+
+	osFlagName := "os"
+	flags.StringVar(&manifestAnnotateOpts.OS, osFlagName, "", "override the `OS` of the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(osFlagName, completion.AutocompleteNone)
+
+	osFeaturesFlagName := "os-features"
+	flags.StringSliceVar(&manifestAnnotateOpts.OSFeatures, osFeaturesFlagName, nil, "override the OS `features` of the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(osFeaturesFlagName, completion.AutocompleteNone)
+
+	osVersionFlagName := "os-version"
+	flags.StringVar(&manifestAnnotateOpts.OSVersion, osVersionFlagName, "", "override the OS `version` of the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(osVersionFlagName, completion.AutocompleteNone)
+
+	variantFlagName := "variant"
+	flags.StringVar(&manifestAnnotateOpts.Variant, variantFlagName, "", "override the `Variant` of the specified image")
+	_ = annotateCmd.RegisterFlagCompletionFunc(variantFlagName, completion.AutocompleteNone)
 }
 
 func annotate(cmd *cobra.Command, args []string) error {
diff --git a/cmd/podman/manifest/create.go b/cmd/podman/manifest/create.go
index 956946f9d..c903c6fa8 100644
--- a/cmd/podman/manifest/create.go
+++ b/cmd/podman/manifest/create.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/pkg/errors"
@@ -13,10 +14,11 @@ import (
 var (
 	manifestCreateOpts = entities.ManifestCreateOptions{}
 	createCmd          = &cobra.Command{
-		Use:   "create [options] LIST [IMAGE]",
-		Short: "Create manifest list or image index",
-		Long:  "Creates manifest lists or image indexes.",
-		RunE:  create,
+		Use:               "create [options] LIST [IMAGE]",
+		Short:             "Create manifest list or image index",
+		Long:              "Creates manifest lists or image indexes.",
+		RunE:              create,
+		ValidArgsFunction: common.AutocompleteImages,
 		Example: `podman manifest create mylist:v1.11
   podman manifest create mylist:v1.11 arch-specific-image-to-add
   podman manifest create --all mylist:v1.11 transport:tagged-image-to-add`,
diff --git a/cmd/podman/manifest/inspect.go b/cmd/podman/manifest/inspect.go
index 19396ceb3..17c94aaba 100644
--- a/cmd/podman/manifest/inspect.go
+++ b/cmd/podman/manifest/inspect.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/pkg/errors"
@@ -16,6 +17,7 @@ var (
 		Short:                 "Display the contents of a manifest list or image index",
 		Long:                  "Display the contents of a manifest list or image index.",
 		RunE:                  inspect,
+		ValidArgsFunction:     common.AutocompleteImages,
 		Example:               "podman manifest inspect localhost/list",
 		Args:                  cobra.ExactArgs(1),
 		DisableFlagsInUseLine: true,
diff --git a/cmd/podman/manifest/push.go b/cmd/podman/manifest/push.go
index 91881c1b3..9d0977834 100644
--- a/cmd/podman/manifest/push.go
+++ b/cmd/podman/manifest/push.go
@@ -2,7 +2,9 @@ package manifest
 
 import (
 	"github.com/containers/common/pkg/auth"
+	"github.com/containers/common/pkg/completion"
 	"github.com/containers/image/v5/types"
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/util"
@@ -22,12 +24,13 @@ type manifestPushOptsWrapper struct {
 var (
 	manifestPushOpts = manifestPushOptsWrapper{}
 	pushCmd          = &cobra.Command{
-		Use:     "push [options] SOURCE DESTINATION",
-		Short:   "Push a manifest list or image index to a registry",
-		Long:    "Pushes manifest lists and image indexes to registries.",
-		RunE:    push,
-		Example: `podman manifest push mylist:v1.11 quay.io/myimagelist`,
-		Args:    cobra.ExactArgs(2),
+		Use:               "push [options] SOURCE DESTINATION",
+		Short:             "Push a manifest list or image index to a registry",
+		Long:              "Pushes manifest lists and image indexes to registries.",
+		RunE:              push,
+		Example:           `podman manifest push mylist:v1.11 quay.io/myimagelist`,
+		Args:              cobra.ExactArgs(2),
+		ValidArgsFunction: common.AutocompleteImages,
 	}
 )
 
@@ -40,13 +43,33 @@ func init() {
 	flags := pushCmd.Flags()
 	flags.BoolVar(&manifestPushOpts.Purge, "purge", false, "remove the manifest list if push succeeds")
 	flags.BoolVar(&manifestPushOpts.All, "all", false, "also push the images in the list")
-	flags.StringVar(&manifestPushOpts.Authfile, "authfile", auth.GetDefaultAuthFile(), "path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
-	flags.StringVar(&manifestPushOpts.CertDir, "cert-dir", "", "use certificates at the specified path to access the registry")
-	flags.StringVar(&manifestPushOpts.CredentialsCLI, "creds", "", "use `[username[:password]]` for accessing the registry")
-	flags.StringVar(&manifestPushOpts.DigestFile, "digestfile", "", "after copying the image, write the digest of the resulting digest to the file")
-	flags.StringVarP(&manifestPushOpts.Format, "format", "f", "", "manifest type (oci or v2s2) to attempt to use when pushing the manifest list (default is manifest type of source)")
+
+	authfileFlagName := "authfile"
+	flags.StringVar(&manifestPushOpts.Authfile, authfileFlagName, auth.GetDefaultAuthFile(), "path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
+	_ = pushCmd.RegisterFlagCompletionFunc(authfileFlagName, completion.AutocompleteDefault)
+
+	certDirFlagName := "cert-dir"
+	flags.StringVar(&manifestPushOpts.CertDir, certDirFlagName, "", "use certificates at the specified path to access the registry")
+	_ = pushCmd.RegisterFlagCompletionFunc(certDirFlagName, completion.AutocompleteDefault)
+
+	credsFlagName := "creds"
+	flags.StringVar(&manifestPushOpts.CredentialsCLI, credsFlagName, "", "use `[username[:password]]` for accessing the registry")
+	_ = pushCmd.RegisterFlagCompletionFunc(credsFlagName, completion.AutocompleteNone)
+
+	digestfileFlagName := "digestfile"
+	flags.StringVar(&manifestPushOpts.DigestFile, digestfileFlagName, "", "after copying the image, write the digest of the resulting digest to the file")
+	_ = pushCmd.RegisterFlagCompletionFunc(digestfileFlagName, completion.AutocompleteDefault)
+
+	formatFlagName := "format"
+	flags.StringVarP(&manifestPushOpts.Format, formatFlagName, "f", "", "manifest type (oci or v2s2) to attempt to use when pushing the manifest list (default is manifest type of source)")
+	_ = pushCmd.RegisterFlagCompletionFunc(formatFlagName, common.AutocompleteManifestFormat)
+
 	flags.BoolVarP(&manifestPushOpts.RemoveSignatures, "remove-signatures", "", false, "don't copy signatures when pushing images")
-	flags.StringVar(&manifestPushOpts.SignBy, "sign-by", "", "sign the image using a GPG key with the specified `FINGERPRINT`")
+
+	signByFlagName := "sign-by"
+	flags.StringVar(&manifestPushOpts.SignBy, signByFlagName, "", "sign the image using a GPG key with the specified `FINGERPRINT`")
+	_ = pushCmd.RegisterFlagCompletionFunc(signByFlagName, completion.AutocompleteNone)
+
 	flags.BoolVar(&manifestPushOpts.TLSVerifyCLI, "tls-verify", true, "require HTTPS and verify certificates when accessing the registry")
 	flags.BoolVarP(&manifestPushOpts.Quiet, "quiet", "q", false, "don't output progress information when pushing lists")
 
diff --git a/cmd/podman/manifest/remove.go b/cmd/podman/manifest/remove.go
index 677d45484..170e68d3f 100644
--- a/cmd/podman/manifest/remove.go
+++ b/cmd/podman/manifest/remove.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/containers/podman/v2/cmd/podman/common"
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/pkg/errors"
@@ -16,6 +17,7 @@ var (
 		Short:                 "Remove an entry from a manifest list or image index",
 		Long:                  "Removes an image from a manifest list or image index.",
 		RunE:                  remove,
+		ValidArgsFunction:     common.AutocompleteImages,
 		Example:               `podman manifest remove mylist:v1.11 sha256:15352d97781ffdf357bf3459c037be3efac4133dc9070c2dce7eca7c05c3e736`,
 		Args:                  cobra.ExactArgs(2),
 		DisableFlagsInUseLine: true,