From 37d87455894a997822f871f51db92e6e77098952 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Gronowski?= <pawel.gronowski@docker.com>
Date: Fri, 24 Jan 2025 17:23:22 +0100
Subject: [PATCH] image/list: Add opt-in to --tree by default
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add a new `image-tree` feature in `~/.docker/config.json` which will
make the `docker image list` use the new tree output by default.
The tree output is only used if no conflicting flag is passed (--format,
--quiet, --digests, --no-trunc).

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
---
 cli/command/image/list.go | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/cli/command/image/list.go b/cli/command/image/list.go
index cfe73c5adeb3..a79552dfec76 100644
--- a/cli/command/image/list.go
+++ b/cli/command/image/list.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strconv"
 
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
@@ -81,6 +82,8 @@ func runImages(ctx context.Context, dockerCLI command.Cli, options imagesOptions
 		filters.Add("reference", options.matchName)
 	}
 
+	options = applyListFeatures(dockerCLI, options)
+
 	if options.tree {
 		if options.quiet {
 			return errors.New("--quiet is not yet supported with --tree")
@@ -167,3 +170,31 @@ func printAmbiguousHint(stdErr io.Writer, matchName string) {
 		_, _ = fmt.Fprintf(stdErr, "\nNo images found matching %q: did you mean \"docker image %[1]s\"?\n", matchName)
 	}
 }
+
+// applyListFeatures checks for feature flags in the config file
+// and adjusts the options accordingly.
+// Supported features:
+// image-tree => --tree option is implied when possible
+func applyListFeatures(dockerCLI command.Cli, options imagesOptions) imagesOptions {
+	cfg := dockerCLI.ConfigFile()
+	var treeOptIn bool
+	if v, ok := cfg.Features["image-tree"]; ok {
+		enabled, err := strconv.ParseBool(v)
+		if err != nil {
+			return options
+		}
+		if enabled {
+			treeOptIn = true
+		}
+	}
+
+	if !options.tree && treeOptIn {
+		treeOptIn = !options.quiet
+		treeOptIn = treeOptIn && !options.noTrunc
+		treeOptIn = treeOptIn && !options.showDigests
+		treeOptIn = treeOptIn && options.format == ""
+		options.tree = treeOptIn
+	}
+
+	return options
+}