cli/cmd: make initialize return a struct

Which will make it easier to return error if some part of initialization
fails.

Signed-off-by: Mateusz Gozdek <mateusz@kinvolk.io>

cli/cmd/cluster-apply.go

@@ -64,12 +64,12 @@ func runClusterApply(cmd *cobra.Command, args []string) {
 
 //nolint:funlen
 func clusterApply(contextLogger *log.Entry) error {
-	ex, p, lokoConfig, assetDir := initialize(contextLogger)
+	c := initialize(contextLogger)
 
-	exists := clusterExists(contextLogger, ex)
+	exists := clusterExists(contextLogger, &c.terraformExecutor)
 	if exists && !confirm {
 		// TODO: We could plan to a file and use it when installing.
-		if err := ex.Plan(); err != nil {
+		if err := c.terraformExecutor.Plan(); err != nil {
 			return fmt.Errorf("reconciling cluster state: %v", err)
 		}
 
@@ -80,18 +80,18 @@ func clusterApply(contextLogger *log.Entry) error {
 		}
 	}
 
-	if err := p.Apply(ex); err != nil {
+	if err := c.platform.Apply(&c.terraformExecutor); err != nil {
 		return fmt.Errorf("applying platform: %v", err)
 	}
 
-	fmt.Printf("\nYour configurations are stored in %s\n", assetDir)
+	fmt.Printf("\nYour configurations are stored in %s\n", c.assetDir)
 
-	kubeconfig, err := getKubeconfig(contextLogger, lokoConfig, true)
+	kubeconfig, err := getKubeconfig(contextLogger, c.lokomotiveConfig, true)
 	if err != nil {
 		return fmt.Errorf("getting kubeconfig: %v", err)
 	}
 
-	if err := verifyCluster(kubeconfig, p.Meta().ExpectedNodes); err != nil {
+	if err := verifyCluster(kubeconfig, c.platform.Meta().ExpectedNodes); err != nil {
 		return fmt.Errorf("verifying cluster: %v", err)
 	}
 
@@ -102,14 +102,14 @@ func clusterApply(contextLogger *log.Entry) error {
 	}
 
 	// Do controlplane upgrades only if cluster already exists and it is not a managed platform.
-	if exists && !p.Meta().Managed {
+	if exists && !c.platform.Meta().Managed {
 		fmt.Printf("\nEnsuring that cluster controlplane is up to date.\n")
 
 		cu := controlplaneUpdater{
 			kubeconfig:    kubeconfig,
-			assetDir:      assetDir,
+			assetDir:      c.assetDir,
 			contextLogger: *contextLogger,
-			ex:            *ex,
+			ex:            c.terraformExecutor,
 		}
 
 		charts := platform.CommonControlPlaneCharts()
@@ -126,7 +126,7 @@ func clusterApply(contextLogger *log.Entry) error {
 		}
 	}
 
-	if ph, ok := p.(platform.PlatformWithPostApplyHook); ok {
+	if ph, ok := c.platform.(platform.PlatformWithPostApplyHook); ok {
 		if err := ph.PostApplyHook(kubeconfig); err != nil {
 			return fmt.Errorf("running platform post install hook: %v", err)
 		}
@@ -137,14 +137,14 @@ func clusterApply(contextLogger *log.Entry) error {
 	}
 
 	componentsToApply := []string{}
-	for _, component := range lokoConfig.RootConfig.Components {
+	for _, component := range c.lokomotiveConfig.RootConfig.Components {
 		componentsToApply = append(componentsToApply, component.Name)
 	}
 
 	contextLogger.Println("Applying component configuration")
 
 	if len(componentsToApply) > 0 {
-		if err := applyComponents(lokoConfig, kubeconfig, componentsToApply...); err != nil {
+		if err := applyComponents(c.lokomotiveConfig, kubeconfig, componentsToApply...); err != nil {
 			return fmt.Errorf("applying component configuration: %v", err)
 		}
 	}

cli/cmd/cluster-destroy.go

@@ -48,9 +48,9 @@ func runClusterDestroy(cmd *cobra.Command, args []string) {
 }
 
 func clusterDestroy(contextLogger *log.Entry) error {
-	ex, p, _, _ := initialize(contextLogger)
+	c := initialize(contextLogger)
 
-	if !clusterExists(contextLogger, ex) {
+	if !clusterExists(contextLogger, &c.terraformExecutor) {
 		contextLogger.Println("Cluster already destroyed, nothing to do")
 
 		return nil
@@ -65,7 +65,7 @@ func clusterDestroy(contextLogger *log.Entry) error {
 		}
 	}
 
-	if err := p.Destroy(ex); err != nil {
+	if err := c.platform.Destroy(&c.terraformExecutor); err != nil {
 		return fmt.Errorf("destroying cluster: %v", err)
 	}
 

cli/cmd/cluster.go

@@ -41,9 +41,18 @@ func init() {
 	RootCmd.AddCommand(clusterCmd)
 }
 
+// cluster is a temporary helper struct to aggregate objects which are used
+// for managing the cluster and components.
+type cluster struct {
+	terraformExecutor terraform.Executor
+	platform          platform.Platform
+	lokomotiveConfig  *config.Config
+	assetDir          string
+}
+
 // initialize does common initialization actions between cluster operations
 // and returns created objects to the caller for further use.
-func initialize(contextLogger *log.Entry) (*terraform.Executor, platform.Platform, *config.Config, string) {
+func initialize(contextLogger *log.Entry) *cluster {
 	lokoConfig, diags := getLokoConfig()
 	if diags.HasErrors() {
 		contextLogger.Fatal(diags)
@@ -85,7 +94,12 @@ func initialize(contextLogger *log.Entry) (*terraform.Executor, platform.Platfor
 
 	ex := initializeTerraform(contextLogger, p, b)
 
-	return ex, p, lokoConfig, assetDir
+	return &cluster{
+		terraformExecutor: *ex,
+		platform:          p,
+		lokomotiveConfig:  lokoConfig,
+		assetDir:          assetDir,
+	}
 }
 
 // initializeTerraform initialized Terraform directory using given backend and platform

cli/cmd/utils.go

@@ -187,11 +187,11 @@ func readKubeconfigFromTerraformState(contextLogger *log.Entry) ([]byte, error)
 	contextLogger.Warn("Kubeconfig file not found in assets directory, pulling kubeconfig from " +
 		"Terraform state, this might be slow. Run 'lokoctl cluster apply' to fix it.")
 
-	ex, _, _, _ := initialize(contextLogger) //nolint:dogsled
+	c := initialize(contextLogger)
 
 	kubeconfig := ""
 
-	if err := ex.Output(kubeconfigTerraformOutputKey, &kubeconfig); err != nil {
+	if err := c.terraformExecutor.Output(kubeconfigTerraformOutputKey, &kubeconfig); err != nil {
 		return nil, fmt.Errorf("reading kubeconfig file content from Terraform state: %w", err)
 	}