✨ Add bootCommands to cloud-init file generation

bootstrap/kubeadm/api/v1beta1/kubeadmconfig_types.go

@@ -75,6 +75,10 @@ type KubeadmConfigSpec struct {
 	// +optional
 	Mounts []MountPoints `json:"mounts,omitempty"`
 
+	// BootCommands specifies extra commands to run very early in the boot process
+	// +optional
+	BootCommands []BootCommand `json:"bootCommands,omitempty"`
+
 	// PreKubeadmCommands specifies extra commands to run before kubeadm runs
 	// +optional
 	PreKubeadmCommands []string `json:"preKubeadmCommands,omitempty"`
@@ -682,3 +686,6 @@ type Filesystem struct {
 
 // MountPoints defines input for generated mounts in cloud-init.
 type MountPoints []string
+
+// BootCommand defines input for each bootcmd command in cloud-init.
+type BootCommand []string

bootstrap/kubeadm/internal/cloudinit/boot_commands.go

@@ -0,0 +1,29 @@
+/*
+Copyright 2019 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 cloudinit
+
+const (
+	bootCommandsTemplate = `{{ define "boot_commands" -}}
+{{- if . }}
+bootcmd:{{ range . }}
+  - {{ range . }}- {{ . }}
+    {{ end -}}
+{{- end -}}
+{{- end -}}
+{{- end -}}
+`
+)

bootstrap/kubeadm/internal/cloudinit/cloudinit.go

@@ -45,6 +45,7 @@ const (
 // BaseUserData is shared across all the various types of files written to disk.
 type BaseUserData struct {
 	Header               string
+	BootCommands         []bootstrapv1.BootCommand
 	PreKubeadmCommands   []string
 	PostKubeadmCommands  []string
 	AdditionalFiles      []bootstrapv1.File
@@ -83,6 +84,10 @@ func generate(kind string, tpl string, data interface{}) ([]byte, error) {
 		return nil, errors.Wrap(err, "failed to parse files template")
 	}
 
+	if _, err := tm.Parse(bootCommandsTemplate); err != nil {
+		return nil, errors.Wrap(err, "failed to parse boot commands template")
+	}
+
 	if _, err := tm.Parse(commandsTemplate); err != nil {
 		return nil, errors.Wrap(err, "failed to parse commands template")
 	}

bootstrap/kubeadm/internal/cloudinit/cloudinit_test.go

@@ -34,6 +34,7 @@ func TestNewInitControlPlaneAdditionalFileEncodings(t *testing.T) {
 	cpinput := &ControlPlaneInput{
 		BaseUserData: BaseUserData{
 			Header:              "test",
+			BootCommands:        nil,
 			PreKubeadmCommands:  nil,
 			PostKubeadmCommands: nil,
 			AdditionalFiles: []bootstrapv1.File{
@@ -95,6 +96,7 @@ func TestNewInitControlPlaneCommands(t *testing.T) {
 	cpinput := &ControlPlaneInput{
 		BaseUserData: BaseUserData{
 			Header:              "test",
+			BootCommands:        nil,
 			PreKubeadmCommands:  []string{`"echo $(date) ': hello world!'"`},
 			PostKubeadmCommands: []string{"echo $(date) ': hello world!'"},
 			AdditionalFiles:     nil,
@@ -132,6 +134,7 @@ func TestNewInitControlPlaneDiskMounts(t *testing.T) {
 	cpinput := &ControlPlaneInput{
 		BaseUserData: BaseUserData{
 			Header:              "test",
+			BootCommands:        nil,
 			PreKubeadmCommands:  nil,
 			PostKubeadmCommands: nil,
 			WriteFiles:          nil,
@@ -195,6 +198,7 @@ func TestNewJoinControlPlaneAdditionalFileEncodings(t *testing.T) {
 	cpinput := &ControlPlaneJoinInput{
 		BaseUserData: BaseUserData{
 			Header:              "test",
+			BootCommands:        nil,
 			PreKubeadmCommands:  nil,
 			PostKubeadmCommands: nil,
 			AdditionalFiles: []bootstrapv1.File{
@@ -247,6 +251,7 @@ func TestNewJoinControlPlaneExperimentalRetry(t *testing.T) {
 	cpinput := &ControlPlaneJoinInput{
 		BaseUserData: BaseUserData{
 			Header:               "test",
+			BootCommands:         nil,
 			PreKubeadmCommands:   nil,
 			PostKubeadmCommands:  nil,
 			UseExperimentalRetry: true,

bootstrap/kubeadm/internal/cloudinit/controlplane_init.go

@@ -35,6 +35,7 @@ const (
     owner: root:root
     permissions: '0640'
     content: "This placeholder file is used to create the /run/cluster-api sub directory in a way that is compatible with both Linux and Windows (mkdir -p /run/cluster-api does not work with Windows)"
+{{- template "boot_commands" .BootCommands }}
 runcmd:
 {{- template "commands" .PreKubeadmCommands }}
   - 'kubeadm init --config /run/kubeadm/kubeadm.yaml {{.KubeadmVerbosity}} && {{ .SentinelFileCommand }}'

bootstrap/kubeadm/internal/cloudinit/controlplane_join.go

@@ -34,6 +34,7 @@ const (
     owner: root:root
     permissions: '0640'
     content: "This placeholder file is used to create the /run/cluster-api sub directory in a way that is compatible with both Linux and Windows (mkdir -p /run/cluster-api does not work with Windows)"
+{{- template "boot_commands" .BootCommands }}
 runcmd:
 {{- template "commands" .PreKubeadmCommands }}
   - {{ .KubeadmCommand }} && {{ .SentinelFileCommand }}

bootstrap/kubeadm/internal/cloudinit/node.go

@@ -29,6 +29,7 @@ const (
     owner: root:root
     permissions: '0640'
     content: "This placeholder file is used to create the /run/cluster-api sub directory in a way that is compatible with both Linux and Windows (mkdir -p /run/cluster-api does not work with Windows)"
+{{- template "boot_commands" .BootCommands }}
 runcmd:
 {{- template "commands" .PreKubeadmCommands }}
   - {{ .KubeadmCommand }} && {{ .SentinelFileCommand }}

bootstrap/kubeadm/internal/controllers/kubeadmconfig_controller.go

@@ -530,6 +530,7 @@ func (r *KubeadmConfigReconciler) handleClusterNotInitialized(ctx context.Contex
 		BaseUserData: cloudinit.BaseUserData{
 			AdditionalFiles:     files,
 			NTP:                 scope.Config.Spec.NTP,
+			BootCommands:        scope.Config.Spec.BootCommands,
 			PreKubeadmCommands:  scope.Config.Spec.PreKubeadmCommands,
 			PostKubeadmCommands: scope.Config.Spec.PostKubeadmCommands,
 			Users:               users,
@@ -651,6 +652,7 @@ func (r *KubeadmConfigReconciler) joinWorker(ctx context.Context, scope *Scope)
 		BaseUserData: cloudinit.BaseUserData{
 			AdditionalFiles:      files,
 			NTP:                  scope.Config.Spec.NTP,
+			BootCommands:         scope.Config.Spec.BootCommands,
 			PreKubeadmCommands:   scope.Config.Spec.PreKubeadmCommands,
 			PostKubeadmCommands:  scope.Config.Spec.PostKubeadmCommands,
 			Users:                users,
@@ -770,6 +772,7 @@ func (r *KubeadmConfigReconciler) joinControlplane(ctx context.Context, scope *S
 		BaseUserData: cloudinit.BaseUserData{
 			AdditionalFiles:      files,
 			NTP:                  scope.Config.Spec.NTP,
+			BootCommands:         scope.Config.Spec.BootCommands,
 			PreKubeadmCommands:   scope.Config.Spec.PreKubeadmCommands,
 			PostKubeadmCommands:  scope.Config.Spec.PostKubeadmCommands,
 			Users:                users,

bootstrap/kubeadm/internal/ignition/clc/clc_test.go

@@ -64,7 +64,6 @@ func TestRender(t *testing.T) {
 		// Test multi-line commands as well.
 		"cat <<EOF > /etc/modules-load.d/containerd.conf\noverlay\nbr_netfilter\nEOF\n",
 	}
-
 	tc := []struct {
 		desc         string
 		input        *cloudinit.BaseUserData
@@ -73,6 +72,11 @@ func TestRender(t *testing.T) {
 		{
 			desc: "renders valid Ignition JSON",
 			input: &cloudinit.BaseUserData{
+				BootCommands: []bootstrapv1.BootCommand{
+					{
+						"boot-command", "another-boot-command",
+					},
+				},
 				PreKubeadmCommands:  preKubeadmCommands,
 				PostKubeadmCommands: postKubeadmCommands,
 				KubeadmCommand:      "kubeadm join",
@@ -269,6 +273,11 @@ func TestRender(t *testing.T) {
 		{
 			desc: "multiple users with password auth",
 			input: &cloudinit.BaseUserData{
+				BootCommands: []bootstrapv1.BootCommand{
+					{
+						"boot-command", "another-boot-command",
+					},
+				},
 				PreKubeadmCommands:  preKubeadmCommands,
 				PostKubeadmCommands: postKubeadmCommands,
 				KubeadmCommand:      "kubeadm join",
@@ -351,6 +360,11 @@ func TestRender(t *testing.T) {
 		{
 			desc: "base64 encoded content",
 			input: &cloudinit.BaseUserData{
+				BootCommands: []bootstrapv1.BootCommand{
+					{
+						"boot-command", "another-boot-command",
+					},
+				},
 				PreKubeadmCommands:  preKubeadmCommands,
 				PostKubeadmCommands: postKubeadmCommands,
 				KubeadmCommand:      "kubeadm join",
@@ -434,6 +448,11 @@ func TestRender(t *testing.T) {
 		{
 			desc: "all file ownership combinations",
 			input: &cloudinit.BaseUserData{
+				BootCommands: []bootstrapv1.BootCommand{
+					{
+						"boot-command", "another-boot-command",
+					},
+				},
 				PreKubeadmCommands:  preKubeadmCommands,
 				PostKubeadmCommands: postKubeadmCommands,
 				KubeadmCommand:      "kubeadm join",