Fix plugin inlining that uses client-pkg dependency (knative#1816)

* Fix plugin inlining that uses client-pkg dependency

* Move list merge into plugin manager

* Fix imports formatting

go.mod

@@ -144,8 +144,11 @@ require (
 )
 
 require (
-	knative.dev/client-pkg v0.0.0-20230425201444-4f052f9ef2f2 // indirect
-	knative.dev/eventing-kafka v0.37.0 // indirect
+	github.com/hashicorp/errwrap v1.1.0
+	github.com/hashicorp/go-cleanhttp v0.5.2
+	knative.dev/client-pkg v0.0.0-20230425201444-4f052f9ef2f2
 )
 
+require knative.dev/eventing-kafka v0.37.0 // indirect
+
 replace knative.dev/kn-plugin-event => github.com/openshift-knative/kn-plugin-event v0.33.1-0.20230821121340-be32652cdd6c

go.sum

@@ -322,6 +322,10 @@ github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t
 github.com/grpc-ecosystem/grpc-gateway v1.14.6/go.mod h1:zdiPV4Yse/1gnckTHtghG4GkDEdKCRJduHpTxT3/jcw=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0 h1:gmcG1KaJ57LophUzW0Hy8NmPhnMZb4M0+kPpLofRdBo=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
+github.com/hashicorp/errwrap v1.1.0 h1:OxrOeh75EUXMY8TBjag2fzXGZ40LB6IKw45YeGUDY2I=
+github.com/hashicorp/errwrap v1.1.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-cleanhttp v0.5.2 h1:035FKYIWjmULyFRBKPs8TBQoi0x6d9G4xc9neXJWAZQ=
+github.com/hashicorp/go-cleanhttp v0.5.2/go.mod h1:kO/YDlP8L1346E6Sodw+PrpBSV4/SoxCXGY6BqNFT48=
 github.com/hashicorp/go-uuid v1.0.2/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=

pkg/kn/plugin/manager.go

@@ -25,13 +25,17 @@ import (
 	"strings"
 	"text/template"
 
+	pkgplugin "knative.dev/client-pkg/pkg/kn/plugin"
+
 	homedir "github.com/mitchellh/go-homedir"
 	"github.com/spf13/cobra"
 )
 
 // Allow plugins to register to this slice for inlining
 var InternalPlugins PluginList
 
+var synced bool
+
 // Interface describing a plugin
 type Plugin interface {
 	// Get the name of the plugin (the file name without extensions)
@@ -104,10 +108,21 @@ func (p PluginList) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
 
 // NewManager creates a new manager for looking up plugins on the file system
 func NewManager(pluginDir string, lookupInPath bool) *Manager {
-	return &Manager{
+	m := &Manager{
 		pluginsDir:   pluginDir,
 		lookupInPath: lookupInPath,
 	}
+	if !synced {
+		for _, p := range pkgplugin.InternalPlugins {
+			m.AppendPlugin(p)
+		}
+		synced = true
+	}
+	return m
+}
+
+func (manager *Manager) AppendPlugin(plugin Plugin) {
+	InternalPlugins = append(InternalPlugins, plugin)
 }
 
 // FindPlugin checks if a plugin for the given parts exist and return it.

pkg/kn/plugin/manager_test.go

@@ -153,6 +153,24 @@ func TestPluginExecute(t *testing.T) {
 	assert.Equal(t, out, "OK arg1 arg2\n")
 }
 
+func TestPluginAppend(t *testing.T) {
+	ctx := setup(t)
+	defer cleanup(t, ctx)
+
+	// Initialize registered plugins
+	defer (prepareInternalPlugins(
+		testPlugin{[]string{"a"}}))()
+
+	pl, err := ctx.pluginManager.ListPlugins()
+	assert.NilError(t, err)
+	assert.Assert(t, len(pl) == 1)
+
+	ctx.pluginManager.AppendPlugin(testPlugin{[]string{"another"}})
+	pl, err = ctx.pluginManager.ListPlugins()
+	assert.NilError(t, err)
+	assert.Assert(t, len(pl) == 2)
+}
+
 func TestPluginMixed(t *testing.T) {
 	ctx := setup(t)
 	defer cleanup(t, ctx)