Merge pull request #54616 from fabriziopandini/kubeadm-doc

Automatic merge from submit-queue (batch tested with PRs 51409, 54616). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Generate kubeadm referencedoc and man pages

**What this PR does / why we need it**:
Improve kubeadm reference doc and start generating kubeadm man pages.
With this PR, also kubeadm will start following the same approach used by other tools

**Which issue this PR fixes** 
initial work for [#265](https://github.com/kubernetes/kubeadm/issues/265)

**Special notes for your reviewer**:
This [document](https://docs.google.com/document/d/1w22y-C1YD1mmqqETxrQrCLnJpzwttscanddgvfYceYY/edit?usp=sharing)  contains the design proposal for how to implement this goal, that will be implemented partially in https://github.com/kubernetes/kubernetes (this PR) and partially in https://github.com/kubernetes/website

In order to keep the PR as small and clean possible I didn't generated new placeholders files under `/docs/man` and `/docs/admin` at this stage. If this is necessary, I will do this later in this PR or eventually in another PR; however, if this is not strictly necessary, IMO we should avoid to pollute this repo with placeholders to file that are maintained in another repo.

cc @kubernetes/sig-docs-maintainers @Bradamant3 @heckj

cmd/genkubedocs/BUILD

@@ -22,6 +22,7 @@ go_library(
         "//cmd/kube-apiserver/app:go_default_library",
         "//cmd/kube-controller-manager/app:go_default_library",
         "//cmd/kube-proxy/app:go_default_library",
+        "//cmd/kubeadm/app/cmd:go_default_library",
         "//cmd/kubelet/app:go_default_library",
         "//plugin/cmd/kube-scheduler/app:go_default_library",
         "//vendor/github.com/spf13/cobra/doc:go_default_library",

cmd/genkubedocs/gen_kube_docs.go

@@ -26,6 +26,7 @@ import (
 	apiservapp "k8s.io/kubernetes/cmd/kube-apiserver/app"
 	cmapp "k8s.io/kubernetes/cmd/kube-controller-manager/app"
 	proxyapp "k8s.io/kubernetes/cmd/kube-proxy/app"
+	kubeadmapp "k8s.io/kubernetes/cmd/kubeadm/app/cmd"
 	kubeletapp "k8s.io/kubernetes/cmd/kubelet/app"
 	schapp "k8s.io/kubernetes/plugin/cmd/kube-scheduler/app"
 )
@@ -73,6 +74,10 @@ func main() {
 		// generate docs for kubelet
 		kubelet := kubeletapp.NewKubeletCommand()
 		doc.GenMarkdownTree(kubelet, outDir)
+	case "kubeadm":
+		// generate docs for kubeadm
+		kubeadm := kubeadmapp.NewKubeadmCommand(os.Stdin, os.Stdout, os.Stderr)
+		doc.GenMarkdownTree(kubeadm, outDir)
 	default:
 		fmt.Fprintf(os.Stderr, "Module %s is not supported", module)
 		os.Exit(1)

cmd/genman/BUILD

@@ -22,6 +22,7 @@ go_library(
         "//cmd/kube-apiserver/app:go_default_library",
         "//cmd/kube-controller-manager/app:go_default_library",
         "//cmd/kube-proxy/app:go_default_library",
+        "//cmd/kubeadm/app/cmd:go_default_library",
         "//cmd/kubelet/app:go_default_library",
         "//pkg/kubectl/cmd:go_default_library",
         "//pkg/kubectl/cmd/util:go_default_library",

cmd/genman/gen_kube_man.go

@@ -31,6 +31,7 @@ import (
 	apiservapp "k8s.io/kubernetes/cmd/kube-apiserver/app"
 	cmapp "k8s.io/kubernetes/cmd/kube-controller-manager/app"
 	proxyapp "k8s.io/kubernetes/cmd/kube-proxy/app"
+	kubeadmapp "k8s.io/kubernetes/cmd/kubeadm/app/cmd"
 	kubeletapp "k8s.io/kubernetes/cmd/kubelet/app"
 	kubectlcmd "k8s.io/kubernetes/pkg/kubectl/cmd"
 	kubectlcmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
@@ -110,6 +111,13 @@ func main() {
 		for _, c := range kubectl.Commands() {
 			genMarkdown(c, "kubectl", outDir)
 		}
+	case "kubeadm":
+		// generate manpage for kubelet
+		kubeadm := kubeadmapp.NewKubeadmCommand(os.Stdin, os.Stdout, os.Stderr)
+		genMarkdown(kubeadm, "", outDir)
+		for _, c := range kubeadm.Commands() {
+			genMarkdown(c, "kubeadm", outDir)
+		}
 	default:
 		fmt.Fprintf(os.Stderr, "Module %s is not supported", module)
 		os.Exit(1)