Split plugin commands into individual files

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

cmd/flux/plugin_update.go

@@ -0,0 +1,102 @@
+/*
+Copyright 2026 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/spf13/cobra"
+
+	"github.com/fluxcd/flux2/v2/internal/plugin"
+)
+
+var pluginUpdateCmd = &cobra.Command{
+	Use:     "update [name]",
+	Aliases: []string{"upgrade"},
+	Short:   "Update installed plugins",
+	Long: `The plugin update command updates installed plugins to their latest versions.
+
+Examples:
+  # Update a single plugin
+  flux plugin update operator
+
+  # Update all installed plugins
+  flux plugin update`,
+	Args: cobra.MaximumNArgs(1),
+	RunE: pluginUpdateCmdRun,
+}
+
+func init() {
+	pluginCmd.AddCommand(pluginUpdateCmd)
+}
+
+func pluginUpdateCmdRun(cmd *cobra.Command, args []string) error {
+	catalogClient := newCatalogClient()
+
+	plugins := pluginHandler.Discover(builtinCommandNames())
+	if len(plugins) == 0 {
+		cmd.Println("No plugins found")
+		return nil
+	}
+
+	// If a specific plugin is requested, filter to just that one.
+	if len(args) == 1 {
+		name := args[0]
+		var found bool
+		for _, p := range plugins {
+			if p.Name == name {
+				plugins = []plugin.Plugin{p}
+				found = true
+				break
+			}
+		}
+		if !found {
+			return fmt.Errorf("plugin %q is not installed", name)
+		}
+	}
+
+	pluginDir := pluginHandler.EnsurePluginDir()
+	installer := plugin.NewInstaller()
+	for _, p := range plugins {
+		result := plugin.CheckUpdate(pluginDir, p.Name, catalogClient, runtime.GOOS, runtime.GOARCH)
+		if result.Err != nil {
+			logger.Failuref("error checking %s: %v", p.Name, result.Err)
+			continue
+		}
+		if result.Skipped {
+			if result.SkipReason == plugin.SkipReasonManual {
+				logger.Warningf("skipping %s (%s)", p.Name, result.SkipReason)
+			} else {
+				logger.Successf("%s already up to date (v%s)", p.Name, result.FromVersion)
+			}
+			continue
+		}
+
+		sp := newPluginSpinner(fmt.Sprintf("updating %s v%s → v%s", p.Name, result.FromVersion, result.ToVersion))
+		sp.Start()
+		if err := installer.Install(pluginDir, result.Manifest, result.Version, result.Platform); err != nil {
+			sp.Stop()
+			logger.Failuref("error updating %s: %v", p.Name, err)
+			continue
+		}
+		sp.Stop()
+		logger.Successf("updated %s v%s → v%s", p.Name, result.FromVersion, result.ToVersion)
+	}
+
+	return nil
+}