cli/cmd: make initializeTerraform() return error

To remove a dependency on log.Entry to make moving this code around
easier and to avoid hiding function complexity from logger.

Also, it no longer requires logger, so argument has been removed.

Part of #630

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

cli/cmd/cluster.go

@@ -92,7 +92,10 @@ func initialize(contextLogger *log.Entry) (*cluster, error) {
 		return nil, fmt.Errorf("validating backend configuration: %v", err)
 	}
 
-	ex := initializeTerraform(contextLogger, p, b)
+	ex, err := initializeTerraform(p, b)
+	if err != nil {
+		return nil, fmt.Errorf("initializing Terraform: %w", err)
+	}
 
 	return &cluster{
 		terraformExecutor: *ex,
@@ -104,21 +107,21 @@ func initialize(contextLogger *log.Entry) (*cluster, error) {
 
 // initializeTerraform initialized Terraform directory using given backend and platform
 // and returns configured executor.
-func initializeTerraform(contextLogger *log.Entry, p platform.Platform, b backend.Backend) *terraform.Executor {
+func initializeTerraform(p platform.Platform, b backend.Backend) (*terraform.Executor, error) {
 	assetDir, err := homedir.Expand(p.Meta().AssetDir)
 	if err != nil {
-		contextLogger.Fatalf("Error expanding path: %v", err)
+		return nil, fmt.Errorf("expanding path %q: %w", p.Meta().AssetDir, err)
 	}
 
 	// Render backend configuration.
 	renderedBackend, err := b.Render()
 	if err != nil {
-		contextLogger.Fatalf("Failed to render backend configuration file: %v", err)
+		return nil, fmt.Errorf("rendering backend configuration: %w", err)
 	}
 
 	// Configure Terraform directory, module and backend.
 	if err := terraform.Configure(assetDir, renderedBackend); err != nil {
-		contextLogger.Fatalf("Failed to configure Terraform : %v", err)
+		return nil, fmt.Errorf("configuring Terraform: %w", err)
 	}
 
 	conf := terraform.Config{
@@ -128,18 +131,18 @@ func initializeTerraform(contextLogger *log.Entry, p platform.Platform, b backen
 
 	ex, err := terraform.NewExecutor(conf)
 	if err != nil {
-		contextLogger.Fatalf("Failed to create Terraform executor: %v", err)
+		return nil, fmt.Errorf("creating Terraform executor: %w", err)
 	}
 
 	if err := p.Initialize(ex); err != nil {
-		contextLogger.Fatalf("Failed to initialize Platform: %v", err)
+		return nil, fmt.Errorf("initializing Platform: %w", err)
 	}
 
 	if err := ex.Init(); err != nil {
-		contextLogger.Fatalf("Failed to initialize Terraform: %v", err)
+		return nil, fmt.Errorf("running 'terraform init': %w", err)
 	}
 
-	return ex
+	return ex, nil
 }
 
 // clusterExists determines if cluster has already been created by getting all