Apply suggestions from code review

Co-authored-by: Andreas Neumann <aneumann@mesosphere.com>

pkg/kudoctl/cmd/diagnostics/print.go

@@ -130,12 +130,13 @@ func (p *PrintableRuntimeObject) print(fs afero.Fs) error {
 		dir += "/" + p.relToParentDir()
 		err := fs.MkdirAll(dir, 0700)
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to create directory %s: %v", dir, err)
 		}
 	}
-	file, err := fs.Create(dir + "/" + name)
+        fileWithPath := fmt.SPrintf("%s/%s", dir, name)
+	file, err := fs.Create(fileWithPath)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to create %s: %v", fileWithPath, err)
 	}
 	printer := printers.YAMLPrinter{}
 	return printer.PrintObj(p.o, file)
@@ -156,9 +157,10 @@ func (p *PrintableYaml) Collect() (Printable, error) {
 func (p *PrintableYaml) print(fs afero.Fs) error {
 	b, err := yaml.Marshal(p.v)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to marshal object to %s/%s.yaml: %v", p.dir(), p.name, err)
 	}
-	return printBytes(fs, b, p.dir()+"/"+p.name+".yaml")
+        fileNameWithPath := fmt.Sprintf("%s/%s.yaml", p.dir(), p.name)
+	return printBytes(fs, b, fileNameWithPath)
 }
 
 type PrintableError struct {
@@ -177,11 +179,11 @@ func (p *PrintableError) print(fs afero.Fs) error {
 func printBytes(fs afero.Fs, b []byte, fileName string) error {
 	file, err := fs.Create(fileName)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to create file %s: %v", fileName, err)
 	}
 	_, err = file.Write(b)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to write to file %s: %v, fileName, err)
 	}
 	return nil
 }

pkg/kudoctl/cmd/diagnostics/resource_funcs.go

@@ -31,15 +31,15 @@ func NewInstanceResources(opts *Options, s *env.Settings) (*ResourceFuncsConfig,
 
 	kc, err := kudo.NewClient(s.KubeConfig, s.RequestTimeout, s.Validate)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to create kudo client: %v", err)
 	}
 	c, err := kube.GetKubeClient(s.KubeConfig)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to create kube client: %v", err)
 	}
 	instance, err := kc.GetInstance(opts.Instance, s.Namespace)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to get instance %s/%s: %v", s.Namespace, opts.Instance, err)
 	}
 
 	return &ResourceFuncsConfig{
@@ -91,7 +91,7 @@ func OperatorVersion(r *ResourceFuncsConfig, ctx *processingContext) (runtime.Ob
 	ovName := ctx.operatorVersionName
 	obj, err := r.kc.GetOperatorVersion(ovName, r.ns)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to get operatorversion %s/%s: %v", r.ns, ovName, err)
 	}
 	if obj == nil {
 		return nil, fmt.Errorf("operator version not found")

pkg/kudoctl/util/kudo/kudo.go

@@ -188,7 +188,7 @@ func (c *Client) GetOperator(name, namespace string) (*v1beta1.Operator, error)
 		return nil, nil
 	}
 	if err != nil {
-		return o, err
+		return o, fmt.Errorf("failed to get operator %/%s: %v", namespace, name, err)
 	}
 	err = setGVKFromScheme(o)
 	return o, err