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>

1 files changed, 39 insertions, 12 deletions

diff --git a/cmd/podman/play/kube.go b/cmd/podman/play/kube.go
index 4f34b2b76..a9e91bd68 100644
--- a/cmd/podman/play/kube.go
+++ b/cmd/podman/play/kube.go
@@ -5,7 +5,9 @@ import (
 	"os"
 
 	"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/cmd/podman/utils"
 	"github.com/containers/podman/v2/pkg/domain/entities"
@@ -31,11 +33,12 @@ var (
   It creates the pod and containers described in the YAML.  The containers within the pod are then started and the ID of the new Pod is output.`
 
 	kubeCmd = &cobra.Command{
-		Use:   "kube [options] KUBEFILE",
-		Short: "Play a pod based on Kubernetes YAML.",
-		Long:  kubeDescription,
-		RunE:  kube,
-		Args:  cobra.ExactArgs(1),
+		Use:               "kube [options] KUBEFILE",
+		Short:             "Play a pod based on Kubernetes YAML.",
+		Long:              kubeDescription,
+		RunE:              kube,
+		Args:              cobra.ExactArgs(1),
+		ValidArgsFunction: completion.AutocompleteDefault,
 		Example: `podman play kube nginx.yml
   podman play kube --creds user:password --seccomp-profile-root /custom/path apache.yml`,
 	}
@@ -50,17 +53,41 @@ func init() {
 
 	flags := kubeCmd.Flags()
 	flags.SetNormalizeFunc(utils.AliasFlags)
-	flags.StringVar(&kubeOptions.CredentialsCLI, "creds", "", "`Credentials` (USERNAME:PASSWORD) to use for authenticating to a registry")
-	flags.StringVar(&kubeOptions.Network, "network", "", "Connect pod to CNI network(s)")
-	flags.StringVar(&kubeOptions.LogDriver, "log-driver", "", "Logging driver for the container")
+
+	credsFlagName := "creds"
+	flags.StringVar(&kubeOptions.CredentialsCLI, credsFlagName, "", "`Credentials` (USERNAME:PASSWORD) to use for authenticating to a registry")
+	_ = kubeCmd.RegisterFlagCompletionFunc(credsFlagName, completion.AutocompleteNone)
+
+	networkFlagName := "network"
+	flags.StringVar(&kubeOptions.Network, networkFlagName, "", "Connect pod to CNI network(s)")
+	_ = kubeCmd.RegisterFlagCompletionFunc(networkFlagName, common.AutocompleteNetworks)
+
+	logDriverFlagName := "log-driver"
+	flags.StringVar(&kubeOptions.LogDriver, logDriverFlagName, "", "Logging driver for the container")
+	_ = kubeCmd.RegisterFlagCompletionFunc(logDriverFlagName, common.AutocompleteLogDriver)
+
 	flags.BoolVarP(&kubeOptions.Quiet, "quiet", "q", false, "Suppress output information when pulling images")
 	flags.BoolVar(&kubeOptions.TLSVerifyCLI, "tls-verify", true, "Require HTTPS and verify certificates when contacting registries")
-	flags.StringVar(&kubeOptions.Authfile, "authfile", auth.GetDefaultAuthFile(), "Path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
+
+	authfileFlagName := "authfile"
+	flags.StringVar(&kubeOptions.Authfile, authfileFlagName, auth.GetDefaultAuthFile(), "Path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
+	_ = kubeCmd.RegisterFlagCompletionFunc(authfileFlagName, completion.AutocompleteDefault)
+
 	if !registry.IsRemote() {
-		flags.StringVar(&kubeOptions.CertDir, "cert-dir", "", "`Pathname` of a directory containing TLS certificates and keys")
+
+		certDirFlagName := "cert-dir"
+		flags.StringVar(&kubeOptions.CertDir, certDirFlagName, "", "`Pathname` of a directory containing TLS certificates and keys")
+		_ = kubeCmd.RegisterFlagCompletionFunc(certDirFlagName, completion.AutocompleteDefault)
+
 		flags.StringVar(&kubeOptions.SignaturePolicy, "signature-policy", "", "`Pathname` of signature policy file (not usually used)")
-		flags.StringVar(&kubeOptions.SeccompProfileRoot, "seccomp-profile-root", defaultSeccompRoot, "Directory path for seccomp profiles")
-		flags.StringSliceVar(&kubeOptions.ConfigMaps, "configmap", []string{}, "`Pathname` of a YAML file containing a kubernetes configmap")
+
+		seccompProfileRootFlagName := "seccomp-profile-root"
+		flags.StringVar(&kubeOptions.SeccompProfileRoot, seccompProfileRootFlagName, defaultSeccompRoot, "Directory path for seccomp profiles")
+		_ = kubeCmd.RegisterFlagCompletionFunc(seccompProfileRootFlagName, completion.AutocompleteDefault)
+
+		configmapFlagName := "configmap"
+		flags.StringSliceVar(&kubeOptions.ConfigMaps, configmapFlagName, []string{}, "`Pathname` of a YAML file containing a kubernetes configmap")
+		_ = kubeCmd.RegisterFlagCompletionFunc(configmapFlagName, completion.AutocompleteDefault)
 	}
 	_ = flags.MarkHidden("signature-policy")
 }