From dbb23a26da59d947ac4e94499c0c366a3842edbf Mon Sep 17 00:00:00 2001
From: Nicklas Frahm <nicklas.frahm@gmail.com>
Date: Mon, 25 Apr 2022 00:18:04 +0200
Subject: [PATCH] fix(engine): merge and upload node config

---
 pkg/engine/config.go | 32 ++++++++++++++++++++++++++++++--
 pkg/engine/engine.go | 38 +++++++++++++++++++++++++++++---------
 pkg/ops/up.go        |  7 ++++---
 3 files changed, 63 insertions(+), 14 deletions(-)

diff --git a/pkg/engine/config.go b/pkg/engine/config.go
index 2cecdf4..874ac27 100644
--- a/pkg/engine/config.go
+++ b/pkg/engine/config.go
@@ -3,6 +3,7 @@ package engine
 import (
 	"errors"
 	"io/ioutil"
+	"reflect"
 
 	"github.com/nicklasfrahm/k3se/pkg/sshx"
 	"gopkg.in/yaml.v3"
@@ -25,6 +26,33 @@ type K3sConfig struct {
 	WriteKubeconfigMode string   `yaml:"write-kubeconfig-mode"`
 	TLSSAN              []string `yaml:"tls-san"`
 	NodeLabel           []string `yaml:"node-label"`
+	Disable             []string `yaml:"disable"`
+	// TODO: Add missing config options as specified here:
+	// https://rancher.com/docs/k3s/latest/en/installation/install-options/server-config/#k3s-server-cli-help
+}
+
+// Merge combines two configurations.
+func (c K3sConfig) Merge(config *K3sConfig) K3sConfig {
+	merged := c
+
+	dst := reflect.ValueOf(&merged).Elem()
+	src := reflect.ValueOf(config).Elem()
+
+	for i := 0; i < src.Type().NumField(); i++ {
+		field := src.Type().Field(i)
+
+		if field.Type.Kind() == reflect.Slice {
+			// Merge slices.
+			dst.Field(i).Set(reflect.AppendSlice(dst.Field(i), src.Field(i)))
+		} else {
+			// Overwrite field value if not empty.
+			if !src.Field(i).IsZero() {
+				dst.Field(i).Set(src.Field(i))
+			}
+		}
+	}
+
+	return merged
 }
 
 // Config describes the state of a k3s cluster. For general
@@ -35,9 +63,9 @@ type Config struct {
 	// channel as specified in the k3s installation options.
 	Version string `yaml:"version"`
 
-	// Config is the desired content of the k3s configuration file
+	// Cluster is the desired content of the k3s configuration file
 	// that is shared among all nodes.
-	Cluster K3sConfig `yaml:"config"`
+	Cluster K3sConfig `yaml:"cluster"`
 
 	// Nodes is a list of nodes to deploy the cluster on. It stores
 	// both, connection information and node-specific configuration.
diff --git a/pkg/engine/engine.go b/pkg/engine/engine.go
index 374978f..ebdea88 100644
--- a/pkg/engine/engine.go
+++ b/pkg/engine/engine.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/nicklasfrahm/k3se/pkg/sshx"
 	"github.com/rs/zerolog"
+	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -20,6 +21,8 @@ type Engine struct {
 
 	sync.Mutex
 	installer []byte
+
+	Spec *Config
 }
 
 // New creates a new Engine.
@@ -57,9 +60,23 @@ func (e *Engine) Installer() ([]byte, error) {
 	return e.installer, nil
 }
 
+// SetSpec configures the desired state of the cluster. Note
+// that the config will only be applied if the verification
+// succeeds.
+func (e *Engine) SetSpec(config *Config) error {
+	if err := config.Verify(); err != nil {
+		return err
+	}
+
+	e.Spec = config
+
+	return nil
+}
+
 // Configure uploads the installer and the configuration
 // prior to a node prior to running the installation.
 func (e *Engine) Configure(node *Node) error {
+	// Upload the installer.
 	installer, err := e.Installer()
 	if err != nil {
 		return err
@@ -69,9 +86,21 @@ func (e *Engine) Configure(node *Node) error {
 		return err
 	}
 
+	// Create the node configuration.
+	config := e.Spec.Cluster.Merge(&node.Config)
+
 	// TODO: Configure the "advertise address" based on the first SAN and modify the
 	// kubeconfig accordingly.
 
+	configBytes, err := yaml.Marshal(config)
+	if err != nil {
+		return err
+	}
+
+	if err := node.Upload("/tmp/k3se/config.yaml", bytes.NewReader(configBytes)); err != nil {
+		return err
+	}
+
 	// TODO: Upload configuration and move it to appropriate location using "sudo".
 
 	return nil
@@ -79,15 +108,6 @@ func (e *Engine) Configure(node *Node) error {
 
 // Cleanup removes all temporary files from the node.
 func (e *Engine) Cleanup(node *Node) error {
-	if err := node.Do(sshx.Cmd{
-		Cmd: "echo $MYVAR > ~/test.txt",
-		Env: map[string]string{
-			"MYVAR": "hello",
-		},
-	}); err != nil {
-		return err
-	}
-
 	return node.Do(sshx.Cmd{
 		Cmd: "rm -rf /tmp/k3se",
 	})
diff --git a/pkg/ops/up.go b/pkg/ops/up.go
index 0814fcc..b97b17f 100644
--- a/pkg/ops/up.go
+++ b/pkg/ops/up.go
@@ -17,15 +17,16 @@ func Up(options ...Option) error {
 	if err != nil {
 		return err
 	}
-	if err := config.Verify(); err != nil {
-		return err
-	}
 
 	eng, err := engine.New(engine.WithLogger(opts.Logger))
 	if err != nil {
 		return err
 	}
 
+	if err := eng.SetSpec(config); err != nil {
+		return err
+	}
+
 	// Establish connection to proxy if host is specified.
 	var sshProxy *sshx.Client
 	if config.SSHProxy.Host != "" {