1. update clientset, deepcopy using code-generator

2. add a dummy file tools.go to force "go mod vendor" to see
code-generator as dependencies
3. add a script to update CRD
4. add a README to document CRD updating steps
run go mod tidy
update README

vendor/k8s.io/code-generator/cmd/conversion-gen/args/args.go

@@ -0,0 +1,83 @@
+/*
+Copyright 2017 The Kubernetes 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 args
+
+import (
+	"fmt"
+
+	"github.com/spf13/pflag"
+	"k8s.io/gengo/args"
+)
+
+// DefaultBasePeerDirs are the peer-dirs nearly everybody will use, i.e. those coming from
+// apimachinery.
+var DefaultBasePeerDirs = []string{
+	"k8s.io/apimachinery/pkg/apis/meta/v1",
+	"k8s.io/apimachinery/pkg/conversion",
+	"k8s.io/apimachinery/pkg/runtime",
+}
+
+// CustomArgs is used by the gengo framework to pass args specific to this generator.
+type CustomArgs struct {
+	// Base peer dirs which nearly everybody will use, i.e. outside of Kubernetes core. Peer dirs
+	// are declared to make the generator pick up manually written conversion funcs from external
+	// packages.
+	BasePeerDirs []string
+
+	// Custom peer dirs which are application specific. Peer dirs are declared to make the
+	// generator pick up manually written conversion funcs from external packages.
+	ExtraPeerDirs []string
+
+	// SkipUnsafe indicates whether to generate unsafe conversions to improve the efficiency
+	// of these operations. The unsafe operation is a direct pointer assignment via unsafe
+	// (within the allowed uses of unsafe) and is equivalent to a proposed Golang change to
+	// allow structs that are identical to be assigned to each other.
+	SkipUnsafe bool
+}
+
+// NewDefaults returns default arguments for the generator.
+func NewDefaults() (*args.GeneratorArgs, *CustomArgs) {
+	genericArgs := args.Default().WithoutDefaultFlagParsing()
+	customArgs := &CustomArgs{
+		BasePeerDirs: DefaultBasePeerDirs,
+		SkipUnsafe:   false,
+	}
+	genericArgs.CustomArgs = customArgs
+	genericArgs.OutputFileBaseName = "conversion_generated"
+	return genericArgs, customArgs
+}
+
+// AddFlags add the generator flags to the flag set.
+func (ca *CustomArgs) AddFlags(fs *pflag.FlagSet) {
+	pflag.CommandLine.StringSliceVar(&ca.BasePeerDirs, "base-peer-dirs", ca.BasePeerDirs,
+		"Comma-separated list of apimachinery import paths which are considered, after tag-specified peers, for conversions. Only change these if you have very good reasons.")
+	pflag.CommandLine.StringSliceVar(&ca.ExtraPeerDirs, "extra-peer-dirs", ca.ExtraPeerDirs,
+		"Application specific comma-separated list of import paths which are considered, after tag-specified peers and base-peer-dirs, for conversions.")
+	pflag.CommandLine.BoolVar(&ca.SkipUnsafe, "skip-unsafe", ca.SkipUnsafe,
+		"If true, will not generate code using unsafe pointer conversions; resulting code may be slower.")
+}
+
+// Validate checks the given arguments.
+func Validate(genericArgs *args.GeneratorArgs) error {
+	_ = genericArgs.CustomArgs.(*CustomArgs)
+
+	if len(genericArgs.OutputFileBaseName) == 0 {
+		return fmt.Errorf("output file base name cannot be empty")
+	}
+
+	return nil
+}

vendor/k8s.io/code-generator/cmd/conversion-gen/main.go

@@ -0,0 +1,125 @@
+/*
+Copyright 2016 The Kubernetes 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.
+*/
+
+// conversion-gen is a tool for auto-generating functions that convert
+// between internal and external types.  A general conversion code
+// generation task involves three sets of packages: (1) a set of
+// packages containing internal types, (2) a single package containing
+// the external types, and (3) a single destination package (i.e.,
+// where the generated conversion functions go, and where the
+// developer-authored conversion functions are).  The packages
+// containing the internal types play the role known as "peer
+// packages" in the general code-generation framework of Kubernetes.
+//
+// For each conversion task, `conversion-gen` will generate functions
+// that efficiently convert between same-name types in the two
+// (internal, external) packages.  The generated functions include
+// ones named
+//     autoConvert_<pkg1>_<type>_To_<pkg2>_<type>
+// for each such pair of types --- both with (pkg1,pkg2) =
+// (internal,external) and (pkg1,pkg2) = (external,internal).
+// Additionally: if the destination package does not contain one in a
+// non-generated file then a function named
+//     Convert_<pkg1>_<type>_To_<pkg2>_<type>
+// is also generated and it simply calls the `autoConvert...`
+// function.  The generated conversion functions use standard value
+// assignment wherever possible.  For compound types, the generated
+// conversion functions call the `Convert...` functions for the
+// subsidiary types.  Thus developers can override the behavior for
+// selected types.  For a top-level object type (i.e., the type of an
+// object that will be input to an apiserver), for such an override to
+// be used by the apiserver the developer-maintained conversion
+// functions must also be registered by invoking the
+// `AddConversionFunc`/`AddGeneratedConversionFunc` method of the
+// relevant `Scheme` object from k8s.io/apimachinery/pkg/runtime.
+//
+// `conversion-gen` will scan its `--input-dirs`, looking at the
+// package defined in each of those directories for comment tags that
+// define a conversion code generation task.  A package requests
+// conversion code generation by including one or more comment in the
+// package's `doc.go` file (currently anywhere in that file is
+// acceptable, but the recommended location is above the `package`
+// statement), of the form:
+//   // +k8s:conversion-gen=<import-path-of-internal-package>
+// This introduces a conversion task, for which the destination
+// package is the one containing the file with the tag and the tag
+// identifies a package containing internal types.  If there is also a
+// tag of the form
+//   // +k8s:conversion-gen-external-types=<import-path-of-external-package>
+// then it identifies the package containing the external types;
+// otherwise they are in the destination package.
+//
+// For each conversion code generation task, the full set of internal
+// packages (AKA peer packages) consists of the ones specified in the
+// `k8s:conversion-gen` tags PLUS any specified in the
+// `--base-peer-dirs` and `--extra-peer-dirs` flags on the command
+// line.
+//
+// When generating for a package, individual types or fields of structs may opt
+// out of Conversion generation by specifying a comment on the of the form:
+//   // +k8s:conversion-gen=false
+package main
+
+import (
+	"flag"
+	"path/filepath"
+
+	"github.com/spf13/pflag"
+	"k8s.io/gengo/args"
+	"k8s.io/klog"
+
+	generatorargs "k8s.io/code-generator/cmd/conversion-gen/args"
+	"k8s.io/code-generator/cmd/conversion-gen/generators"
+	"k8s.io/code-generator/pkg/util"
+)
+
+func main() {
+	klog.InitFlags(nil)
+	genericArgs, customArgs := generatorargs.NewDefaults()
+
+	// Override defaults.
+	// TODO: move this out of conversion-gen
+	genericArgs.GoHeaderFilePath = filepath.Join(args.DefaultSourceTree(), util.BoilerplatePath())
+
+	genericArgs.AddFlags(pflag.CommandLine)
+	customArgs.AddFlags(pflag.CommandLine)
+	flag.Set("logtostderr", "true")
+	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+	pflag.Parse()
+
+	// k8s.io/apimachinery/pkg/runtime contains a number of manual conversions,
+	// that we need to generate conversions.
+	// Packages being dependencies of explicitly requested packages are only
+	// partially scanned - only types explicitly used are being traversed.
+	// Not used functions or types are omitted.
+	// Adding this explicitly to InputDirs ensures that the package is fully
+	// scanned and all functions are parsed and processed.
+	genericArgs.InputDirs = append(genericArgs.InputDirs, "k8s.io/apimachinery/pkg/runtime")
+
+	if err := generatorargs.Validate(genericArgs); err != nil {
+		klog.Fatalf("Error: %v", err)
+	}
+
+	// Run it.
+	if err := genericArgs.Execute(
+		generators.NameSystems(),
+		generators.DefaultNameSystem(),
+		generators.Packages,
+	); err != nil {
+		klog.Fatalf("Error: %v", err)
+	}
+	klog.V(2).Info("Completed successfully.")
+}