*: add auto-gen for codegen scripts

pkg/generator/codegen_tmpls.go

@@ -0,0 +1,31 @@
+package generator
+
+const boilerplateTmpl = `/*
+Copyright YEAR The {{.ProjectName}} Authors
+
+Commercial software license.
+*/
+`
+
+const updateGeneratedTmpl = `#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+DOCKER_REPO_ROOT="/go/src/{{.RepoPath}}"
+IMAGE=${IMAGE:-"gcr.io/coreos-k8s-scale-testing/codegen"}
+
+docker run --rm \
+  -v "$PWD":"$DOCKER_REPO_ROOT" \
+  -w "$DOCKER_REPO_ROOT" \
+  "$IMAGE" \
+  "/go/src/k8s.io/code-generator/generate-groups.sh"  \
+  "all" \
+  "{{.RepoPath}}/pkg/generated" \
+  "{{.RepoPath}}/pkg/apis" \
+  "{{.APIDirName}}:{{.Version}}" \
+  --go-header-file "./hack/codegen/boilerplate.go.txt" \
+  $@
+.
+`

pkg/generator/gen_codegen.go

@@ -0,0 +1,48 @@
+package generator
+
+import (
+	"io"
+	"text/template"
+)
+
+// Boilerplate contains all the customized data needed to generate codegen/boilerplate.go.txt
+// for a new operator when pairing with boilerplateTmpl template.
+type Boilerplate struct {
+	ProjectName string
+}
+
+// UpdateGenerated contains all the customized data needed to generate codegen/update-generated.sh
+// for a new operator when pairing with updateGeneratedTmpl template.
+type UpdateGenerated struct {
+	RepoPath   string
+	APIDirName string
+	Version    string
+}
+
+func renderBoilerplateFile(w io.Writer, projectName string) error {
+	t := template.New("codegen/boilerplate.go.txt")
+	t, err := t.Parse(boilerplateTmpl)
+	if err != nil {
+		return err
+	}
+
+	b := Boilerplate{
+		ProjectName: projectName,
+	}
+	return t.Execute(w, b)
+}
+
+func renderUpdateGeneratedFile(w io.Writer, repo, apiDirName, version string) error {
+	t := template.New("codegen/boilerplate.go.txt")
+	t, err := t.Parse(updateGeneratedTmpl)
+	if err != nil {
+		return err
+	}
+
+	b := UpdateGenerated{
+		RepoPath:   repo,
+		APIDirName: apiDirName,
+		Version:    version,
+	}
+	return t.Execute(w, b)
+}