main: Error out if an unrecognized subcommand is provided

Surprisingly, the spf13/cobra CLI parsing logic, when presented
with an unknown subcommand outputs usage to stdout
and *exits successfully*.

This is bad for both users and scripts.  Cargo cult some code
I found in podman to handle this.

Motivated by https://github.com/containers/containers-image-proxy-rs/pull/1

Signed-off-by: Colin Walters <walters@verbum.org>
This commit is contained in:
Colin Walters
2021-10-29 12:10:39 -04:00
committed by Lokesh Mandvekar
parent c2732cb15d
commit 4acc9f0d2c

View File

@@ -3,6 +3,7 @@ package main
import (
"context"
"fmt"
"strings"
"time"
commonFlag "github.com/containers/common/pkg/flag"
@@ -34,6 +35,21 @@ type globalOptions struct {
tmpDir string // Path to use for big temporary files
}
// requireSubcommand returns an error if no sub command is provided
// This was copied from podman: `github.com/containers/podman/cmd/podman/validate/args.go
// Some small style changes to match skopeo were applied, but try to apply any
// bugfixes there first.
func requireSubcommand(cmd *cobra.Command, args []string) error {
if len(args) > 0 {
suggestions := cmd.SuggestionsFor(args[0])
if len(suggestions) == 0 {
return fmt.Errorf("Unrecognized command `%[1]s %[2]s`\nTry '%[1]s --help' for more information", cmd.CommandPath(), args[0])
}
return fmt.Errorf("Unrecognized command `%[1]s %[2]s`\n\nDid you mean this?\n\t%[3]s\n\nTry '%[1]s --help' for more information", cmd.CommandPath(), args[0], strings.Join(suggestions, "\n\t"))
}
return fmt.Errorf("Missing command '%[1]s COMMAND'\nTry '%[1]s --help' for more information", cmd.CommandPath())
}
// createApp returns a cobra.Command, and the underlying globalOptions object, to be run or tested.
func createApp() (*cobra.Command, *globalOptions) {
opts := globalOptions{}
@@ -41,6 +57,7 @@ func createApp() (*cobra.Command, *globalOptions) {
rootCommand := &cobra.Command{
Use: "skopeo",
Long: "Various operations with container images and container image registries",
RunE: requireSubcommand,
PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
return opts.before(cmd)
},