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

2 files changed, 50 insertions, 13 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{}
diff --git a/src/k8splugin/internal/helm/helm_test.go b/src/k8splugin/internal/helm/helm_test.go
index 1e676c52..817bbaa3 100644
--- a/src/k8splugin/internal/helm/helm_test.go
+++ b/src/k8splugin/internal/helm/helm_test.go
@@ -155,6 +155,33 @@ func TestGenerateKubernetesArtifacts(t *testing.T) {
 			},
 			expectedError: "",
 		},
+		{
+			label:      "Generate artifacts from multi-template and empty files v1",
+			chartPath:  "../../mock_files/mock_charts/testchart3",
+			valueFiles: []string{},
+			values: []string{
+				"goingEmpty=false",
+			},
+			expectedHashMap: map[string]string{
+				"testchart3/templates/multi.yaml-2": "e24cbbefac2c2f700880b8fd041838f2dd48bbc1e099e7c1d2485ae7feb3da0d",
+				"testchart3/templates/multi.yaml-3": "592a8e5b2c35b8469aa45703a835bc00657bfe36b51eb08427a46e7d22fb1525",
+			},
+			expectedError: "",
+		},
+		{
+			label:      "Generate artifacts from multi-template and empty files v2",
+			chartPath:  "../../mock_files/mock_charts/testchart3",
+			valueFiles: []string{},
+			values: []string{
+				"goingEmpty=true",
+			},
+			expectedHashMap: map[string]string{
+				"testchart3/templates/multi.yaml-3": "e24cbbefac2c2f700880b8fd041838f2dd48bbc1e099e7c1d2485ae7feb3da0d",
+				"testchart3/templates/multi.yaml-4": "0bea01e65148584609ede5000c024241ba1c35b440b32ec0a4f7013015715bfe",
+				"testchart3/templates/multi.yaml-5": "6a5af22538c273b9d4a3156e3b6bb538c655041eae31e93db21a9e178f73ecf0",
+			},
+			expectedError: "",
+		},
 	}
 
 	h := sha256.New()
@@ -192,7 +219,7 @@ func TestGenerateKubernetesArtifacts(t *testing.T) {
 						}
 					}
 					if gotHash != expectedHash {
-						t.Fatalf("Got unexpected hash for %s", f)
+						t.Fatalf("Got unexpected hash for %s: '%s'; expected: '%s'", f, gotHash, expectedHash)
 					}
 				}
 			}