ADDED logic for prune command

commands/prune.go

@@ -1,28 +1,91 @@
 package commands
 
 import (
+  "context"
 	"fmt"
+	"strings"
 
   "github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/opts"
+	"github.com/docker/docker/api/types"
+	units "github.com/docker/go-units"
 	"github.com/spf13/cobra"
 )
 
-func runPrune(dockerCli command.Cli) error {
-	fmt.Println("ASDF run prune")
-	return nil
+type pruneOptions struct {
+  force       bool
+  all         bool
+  filter      opts.FilterOpt
+  keepStorage opts.MemBytes
+}
+
+const (
+	normalWarning   = `WARNING! This will remove all dangling build cache. Are you sure you want to continue?`
+	allCacheWarning = `WARNING! This will remove all build cache. Are you sure you want to continue?`
+)
+
+func runPrune(dockerCli command.Cli, options pruneOptions) (spaceReclaimed uint64, output string, err error) {
+	pruneFilters := options.filter.Value()
+  pruneFilters = command.PruneFilters(dockerCli, pruneFilters)
+
+  warning := normalWarning
+  if options.all {
+    warning = allCacheWarning
+  }
+  if !options.force && !command.PromptForConfirmation(dockerCli.In(), dockerCli.Out(), warning) {
+    return 0, "", nil
+  }
+
+  report, err := dockerCli.Client().BuildCachePrune(context.Background(), types.BuildCachePruneOptions{
+    All:         options.all,
+    KeepStorage: options.keepStorage.Value(),
+    Filters:     pruneFilters,
+  })
+  if err != nil {
+    return 0, "", err
+  }
+
+  if len(report.CachesDeleted) > 0 {
+    var sb strings.Builder
+    sb.WriteString("Deleted build cache objects:\n")
+    for _, id := range report.CachesDeleted {
+      sb.WriteString(id)
+      sb.WriteByte('\n')
+    }
+    output = sb.String()
+  }
+
+	return report.SpaceReclaimed, output, nil
 }
 
 func pruneCmd(dockerCli command.Cli) *cobra.Command {
-  fmt.Println("ASDF prune command added")
+  options := pruneOptions{filter: opts.NewFilterOpt()}
 
 	cmd := &cobra.Command{
 		Use:   "prune",
-		Short: "clear the buildx build cache ",
-		Args:  cli.ExactArgs(0),
+		Short: "Remove build cache ",
+		Args:  cli.NoArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return runPrune(dockerCli)
+			spaceReclaimed, output, err := runPrune(dockerCli, options)
+      if err != nil {
+        return err
+      }
+      if output != "" {
+        fmt.Fprintln(dockerCli.Out(), output)
+      }
+      fmt.Fprintln(dockerCli.Out(), "Total reclaimed space:", units.HumanSize(float64(spaceReclaimed)))
+      return nil
 		},
+    Annotations: map[string]string{"version":"1.00"},
+
 	}
+
+flags := cmd.Flags()
+flags.BoolVarP(&options.force, "force", "f", false, "Do not prompt for confirmation")
+flags.BoolVarP(&options.all, "all", "a", false, "Remove all unused images, not just dangling ones")
+flags.Var(&options.filter, "filter", "Provide filter values (e.g. 'unused-for=24h')")
+flags.Var(&options.keepStorage, "keep-storage", "Amount of disk space to keep for cache")
+
 	return cmd
 }