bake: add completion to list targets

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

bake/bake.go

@@ -85,6 +85,21 @@ func ReadLocalFiles(names []string) ([]File, error) {
 	return out, nil
 }
 
+func ListTargets(files []File) ([]string, error) {
+	c, err := ParseFiles(files, nil)
+	if err != nil {
+		return nil, err
+	}
+	var targets []string
+	for _, g := range c.Groups {
+		targets = append(targets, g.Name)
+	}
+	for _, t := range c.Targets {
+		targets = append(targets, t.Name)
+	}
+	return dedupSlice(targets), nil
+}
+
 func ReadTargets(ctx context.Context, files []File, targets, overrides []string, defaults map[string]string) (map[string]*Target, map[string]*Group, error) {
 	c, err := ParseFiles(files, defaults)
 	if err != nil {

commands/bake.go

@@ -11,6 +11,7 @@ import (
 	"github.com/docker/buildx/build"
 	"github.com/docker/buildx/builder"
 	"github.com/docker/buildx/util/buildflags"
+	"github.com/docker/buildx/util/cobrautil/completion"
 	"github.com/docker/buildx/util/confutil"
 	"github.com/docker/buildx/util/dockerutil"
 	"github.com/docker/buildx/util/progress"
@@ -230,6 +231,7 @@ func bakeCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 			// Other common flags (noCache, pull and progress) are processed in runBake function.
 			return runBake(dockerCli, args, options, cFlags)
 		},
+		ValidArgsFunction: completion.BakeTargets(options.files),
 	}
 
 	flags := cmd.Flags()

util/cobrautil/completion/completion.go

@@ -1,6 +1,9 @@
 package completion
 
 import (
+	"strings"
+
+	"github.com/docker/buildx/bake"
 	"github.com/spf13/cobra"
 )
 
@@ -10,3 +13,26 @@ type ValidArgsFn func(cmd *cobra.Command, args []string, toComplete string) ([]s
 func Disable(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 	return nil, cobra.ShellCompDirectiveNoSpace
 }
+
+func BakeTargets(files []string) ValidArgsFn {
+	return func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		f, err := bake.ReadLocalFiles(files)
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+		tgts, err := bake.ListTargets(f)
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+		var filtered []string
+		if toComplete == "" {
+			return tgts, cobra.ShellCompDirectiveNoFileComp
+		}
+		for _, tgt := range tgts {
+			if strings.HasPrefix(tgt, toComplete) {
+				filtered = append(filtered, tgt)
+			}
+		}
+		return filtered, cobra.ShellCompDirectiveNoFileComp
+	}
+}