Improve early-detection of empty template

Previous empty template detection pattern matched only against templates
resolved to empty-or-whitespace-only files. This change makes it handle
other case of empty yaml correctly, namely, yaml containing comments
only.

Issue-ID: MULTICLOUD-1252
Signed-off-by: Konrad Bańka <k.banka@samsung.com>
Change-Id: I9132e167ec607c8a4a4ca5584141ed043c6ddd4f

1 files changed, 22 insertions, 12 deletions

diff --git a/src/k8splugin/internal/helm/helm.go b/src/k8splugin/internal/helm/helm.go
index 2150758b..d3715fce 100644
--- a/src/k8splugin/internal/helm/helm.go
+++ b/src/k8splugin/internal/helm/helm.go
@@ -23,6 +23,7 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"sort"
 	"strings"
 
 	utils "github.com/onap/multicloud-k8s/src/k8splugin/internal"
@@ -55,16 +56,17 @@ type Template interface {
 // TemplateClient implements the Template interface
 // It will also be used to maintain any localized state
 type TemplateClient struct {
-	whitespaceRegex *regexp.Regexp
-	kubeVersion     string
-	kubeNameSpace   string
-	releaseName     string
+	emptyRegex    *regexp.Regexp
+	kubeVersion   string
+	kubeNameSpace string
+	releaseName   string
 }
 
 // NewTemplateClient returns a new instance of TemplateClient
 func NewTemplateClient(k8sversion, namespace, releasename string) *TemplateClient {
 	return &TemplateClient{
-		whitespaceRegex: regexp.MustCompile(`^\s*$`),
+		// emptyRegex defines template content that could be considered empty yaml-wise
+		emptyRegex: regexp.MustCompile(`(?m)\A(^(\s*#.*|\s*)$\n?)*\z`),
 		// defaultKubeVersion is the default value of --kube-version flag
 		kubeVersion:   k8sversion,
 		kubeNameSpace: namespace,
@@ -209,11 +211,19 @@ func (h *TemplateClient) GenerateKubernetesArtifacts(inputPath string, valueFile
 			continue
 		}
 		rmap := releaseutil.SplitManifests(v)
-		count := 0
-		for _, v1 := range rmap {
-			key := fmt.Sprintf("%s-%d", k, count)
-			newRenderedTemplates[key] = v1
-			count = count + 1
+
+		// Iterating over map can yield different order at times
+		// so first we'll sort keys
+		sortedKeys := make([]string, len(rmap))
+		for k1, _ := range rmap {
+			sortedKeys = append(sortedKeys, k1)
+		}
+		// This makes empty files have the lowest indices
+		sort.Strings(sortedKeys)
+
+		for k1, v1 := range sortedKeys {
+			key := fmt.Sprintf("%s-%d", k, k1)
+			newRenderedTemplates[key] = rmap[v1]
 		}
 	}
 
@@ -232,7 +242,7 @@ func (h *TemplateClient) GenerateKubernetesArtifacts(inputPath string, valueFile
 		}
 
 		// blank template after execution
-		if h.whitespaceRegex.MatchString(data) {
+		if h.emptyRegex.MatchString(data) {
 			continue
 		}
 
@@ -260,7 +270,7 @@ func (h *TemplateClient) GenerateKubernetesArtifacts(inputPath string, valueFile
 func getGroupVersionKind(data string) (schema.GroupVersionKind, error) {
 	out, err := k8syaml.ToJSON([]byte(data))
 	if err != nil {
-		return schema.GroupVersionKind{}, pkgerrors.Wrap(err, "Converting yaml to json")
+		return schema.GroupVersionKind{}, pkgerrors.Wrap(err, "Converting yaml to json:\n"+data)
 	}
 
 	simpleMeta := json.SimpleMetaFactory{}