From e846cf71a1041ff86d085071860d20ad00f85f0a Mon Sep 17 00:00:00 2001
From: Kimmo Lehto <klehto@mirantis.com>
Date: Mon, 6 May 2024 14:44:46 +0300
Subject: [PATCH] Clean up version: null from "k0sctl init" output (#641)

Signed-off-by: Kimmo Lehto <klehto@mirantis.com>
---
 phase/default_k0s_version.go                  |  2 +-
 .../v1beta1/cluster/k0s.go                    | 30 +++++++++++++++----
 .../v1beta1/cluster/spec.go                   | 17 +++++++++--
 3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/phase/default_k0s_version.go b/phase/default_k0s_version.go
index 571cd1ad..1a88a1a6 100644
--- a/phase/default_k0s_version.go
+++ b/phase/default_k0s_version.go
@@ -21,7 +21,7 @@ func (p *DefaultK0sVersion) Title() string {
 }
 
 func (p *DefaultK0sVersion) Run() error {
-	isStable := p.Config.Spec.K0s.VersionChannel == "stable"
+	isStable := p.Config.Spec.K0s.VersionChannel == "" || p.Config.Spec.K0s.VersionChannel == "stable"
 
 	var msg string
 	if isStable {
diff --git a/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/k0s.go b/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/k0s.go
index 315125ec..453bd80b 100644
--- a/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/k0s.go
+++ b/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/k0s.go
@@ -31,10 +31,10 @@ var (
 
 // K0s holds configuration for bootstraping a k0s cluster
 type K0s struct {
-	Version        *version.Version `yaml:"version"`
-	VersionChannel string           `yaml:"versionChannel" default:"stable"`
-	DynamicConfig  bool             `yaml:"dynamicConfig"`
-	Config         dig.Mapping      `yaml:"config"`
+	Version        *version.Version `yaml:"version,omitempty"`
+	VersionChannel string           `yaml:"versionChannel,omitempty"`
+	DynamicConfig  bool             `yaml:"dynamicConfig,omitempty" default:"false"`
+	Config         dig.Mapping      `yaml:"config,omitempty"`
 	Metadata       K0sMetadata      `yaml:"-"`
 }
 
@@ -56,6 +56,26 @@ func (k *K0s) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return defaults.Set(k)
 }
 
+// MarshalYAML implements yaml.Marshaler interface
+func (k *K0s) MarshalYAML() (interface{}, error) {
+	if k == nil {
+		return nil, nil
+	}
+	type k0s K0s
+	yk := (*k0s)(k)
+
+	yml, err := yaml.Marshal(yk)
+	if err != nil {
+		return nil, fmt.Errorf("marshal k0s: %w", err)
+	}
+
+	if string(yml) == "{}\n" {
+		return nil, nil
+	}
+
+	return yk, nil
+}
+
 // SetDefaults sets default values
 func (k *K0s) SetDefaults() {
 	if k.Version == nil {
@@ -88,7 +108,7 @@ func (k *K0s) Validate() error {
 	return validation.ValidateStruct(k,
 		validation.Field(&k.Version, validation.By(validateVersion)),
 		validation.Field(&k.DynamicConfig, validation.By(k.validateMinDynamic())),
-		validation.Field(&k.VersionChannel, validation.In("stable", "latest")),
+		validation.Field(&k.VersionChannel, validation.In("stable", "latest"), validation.When(k.VersionChannel != "")),
 	)
 }
 
diff --git a/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/spec.go b/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/spec.go
index e25c7b8c..02a6dc49 100644
--- a/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/spec.go
+++ b/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/spec.go
@@ -9,8 +9,8 @@ import (
 
 // Spec defines cluster config spec section
 type Spec struct {
-	Hosts Hosts `yaml:"hosts"`
-	K0s   *K0s  `yaml:"k0s"`
+	Hosts Hosts `yaml:"hosts,omitempty"`
+	K0s   *K0s  `yaml:"k0s,omitempty"`
 
 	k0sLeader *Host
 }
@@ -28,6 +28,19 @@ func (s *Spec) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return defaults.Set(s)
 }
 
+// MarshalYAML implements yaml.Marshaler interface
+func (s *Spec) MarshalYAML() (interface{}, error) {
+	k0s, err := s.K0s.MarshalYAML()
+	if err != nil {
+		return nil, err
+	}
+	if k0s == nil {
+		return Spec{Hosts: s.Hosts}, nil
+	}
+
+	return s, nil
+}
+
 // SetDefaults sets defaults
 func (s *Spec) SetDefaults() {
 	if s.K0s == nil {