One plugin per dir.

plugin/builtin/secretgenerator/SecretGenerator.go

@@ -0,0 +1,38 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:generate go run sigs.k8s.io/kustomize/plugin/pluginator
+package main
+
+import (
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/types"
+	"sigs.k8s.io/yaml"
+)
+
+type plugin struct {
+	ldr ifc.Loader
+	rf  *resmap.Factory
+	types.GeneratorOptions
+	types.SecretArgs
+}
+
+var KustomizePlugin plugin
+
+func (p *plugin) Config(
+	ldr ifc.Loader, rf *resmap.Factory, config []byte) (err error) {
+	p.GeneratorOptions = types.GeneratorOptions{}
+	p.SecretArgs = types.SecretArgs{}
+	err = yaml.Unmarshal(config, p)
+	p.ldr = ldr
+	p.rf = rf
+	return
+}
+
+func (p *plugin) Generate() (resmap.ResMap, error) {
+	argsList := make([]types.SecretArgs, 1)
+	argsList[0] = p.SecretArgs
+	return p.rf.NewResMapFromSecretArgs(
+		p.ldr, &p.GeneratorOptions, argsList)
+}