feat(helm): add --with-subcharts option for "helm inspect values"

Running helm inspect values [CHART] outputs the contents of a chart's values.yaml verbatim. This is often used to determine which configuration options a chart exposes. However, it does not provide the contents of values.yaml files of potential subcharts bundled in the charts subdirectory. The new command-line option --with-subcharts causes Helm to merge the values.yaml files of a chart and all its subcharts and output the result.

Closes #3926

cmd/helm/inspect.go

@@ -26,6 +26,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"k8s.io/helm/pkg/chartutil"
+	"k8s.io/helm/pkg/proto/hapi/chart"
 	"k8s.io/kubernetes/pkg/util/slice"
 )
 
@@ -52,15 +53,16 @@ of the README file
 `
 
 type inspectCmd struct {
-	chartpath string
+	chartpath     string
-	output    string
+	output        string
-	verify    bool
+	verify        bool
-	keyring   string
+	withSubcharts bool
-	out       io.Writer
+	keyring       string
-	version   string
+	out           io.Writer
-	repoURL   string
+	version       string
-	username  string
+	repoURL       string
-	password  string
+	username      string
+	password      string
 
 	certFile string
 	keyFile  string
@@ -164,6 +166,10 @@ func newInspectCmd(out io.Writer) *cobra.Command {
 		subCmd.Flags().BoolVar(&insp.verify, vflag, false, vdesc)
 	}
 
+	withSubcharts := "with-subcharts"
+	withSubchartsDescr := "recursively merges values.yaml files of this chart and all of its subcharts"
+	valuesSubCmd.Flags().BoolVar(&insp.withSubcharts, withSubcharts, false, withSubchartsDescr)
+
 	kflag := "keyring"
 	kdesc := "path to the keyring containing public verification keys"
 	kdefault := defaultKeyring()
@@ -238,7 +244,17 @@ func (i *inspectCmd) run() error {
 		if i.output == all {
 			fmt.Fprintln(i.out, "---")
 		}
-		fmt.Fprintln(i.out, chrt.Values.Raw)
+		if i.withSubcharts {
+			mergedOutput, err := coalesceValues(chrt)
+
+			if err != nil {
+				return err
+			}
+
+			fmt.Fprintln(i.out, mergedOutput)
+		} else {
+			fmt.Fprintln(i.out, chrt.Values.Raw)
+		}
 	}
 
 	if i.output == readmeOnly || i.output == all {
@@ -254,6 +270,58 @@ func (i *inspectCmd) run() error {
 	return nil
 }
 
+func coalesceValues(chrt *chart.Chart) (string, error) {
+	mainVal, err := chartutil.CoalesceValues(chrt, chrt.Values)
+	if err != nil {
+		return "", err
+	}
+
+	mainValMap := mainVal.AsMap()
+	coalescedGlobals := map[string]interface{}{}
+	coalesceGlobals(&mainVal, &coalescedGlobals)
+
+	if len(coalescedGlobals) > 0 {
+		mainValMap[chartutil.GlobalKey] = &coalescedGlobals
+	}
+
+	s, err := chartutil.Values(mainValMap).YAML()
+	return s, err
+}
+
+func coalesceGlobals(src *chartutil.Values, destGlob *map[string]interface{}) {
+	for key, val := range *src {
+		if key == chartutil.GlobalKey || val == nil {
+			continue
+		}
+
+		if subVal, ok := val.(map[string]interface{}); ok {
+			coalesceGlobalsRecursive(&subVal, destGlob)
+		}
+	}
+}
+
+func coalesceGlobalsRecursive(src *map[string]interface{}, destGlob *map[string]interface{}) {
+	for key, val := range *src {
+		if key == chartutil.GlobalKey && val != nil {
+			valMap := val.(map[string]interface{})
+			for globKey, globVal := range valMap {
+				if _, exists := (*destGlob)[globKey]; !exists {
+					(*destGlob)[globKey] = globVal
+				}
+			}
+
+			delete(*src, chartutil.GlobalKey)
+			continue
+		}
+
+		if valMap, ok := val.(map[string]interface{}); ok {
+			if _, globExists := valMap[chartutil.GlobalKey]; globExists {
+				coalesceGlobalsRecursive(&valMap, destGlob)
+			}
+		}
+	}
+}
+
 func findReadme(files []*any.Any) (file *any.Any) {
 	for _, file := range files {
 		if slice.ContainsString(readmeFileNames, strings.ToLower(file.TypeUrl), nil) {

cmd/helm/inspect_test.go

@@ -78,3 +78,20 @@ func TestInspect(t *testing.T) {
 		t.Errorf("expected empty values buffer, got %q", b.String())
 	}
 }
+
+func TestInspectWithSubCharts(t *testing.T) {
+	expected, _ := ioutil.ReadFile("testdata/testcharts/chart-globals-inspect-values-with-subcharts/expected.yml")
+	b := bytes.NewBuffer(nil)
+
+	insp := &inspectCmd{
+		chartpath:     "testdata/testcharts/chart-globals-inspect-values-with-subcharts",
+		output:        all,
+		out:           b,
+		withSubcharts: true,
+	}
+	insp.run()
+
+	if b.String() != string(expected) {
+		t.Fatalf("Expected:\n%s \nbut got:\n%s", expected, b.String())
+	}
+}

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/Chart.yaml

@@ -0,0 +1,3 @@
+description: A Helm chart for Kubernetes
+name: chart-globals-inspect-values-with-subcharts
+version: 0.1.0

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/charts/subchart1/Chart.yaml

@@ -0,0 +1,3 @@
+description: A Helm chart for Kubernetes
+name: chart-globals-inspect-values-with-subcharts-subchart1
+version: 0.1.0

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/charts/subchart1/charts/subsubchart/Chart.yaml

@@ -0,0 +1,3 @@
+description: A Helm chart for Kubernetes
+name: chart-globals-inspect-values-with-subcharts-subchart1-subsubchart
+version: 0.1.0

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/charts/subchart1/charts/subsubchart/values.yaml

@@ -0,0 +1,5 @@
+global:
+    key1: from subsubchart
+    key5: from subsubchart
+        
+subsubchartKey: 'subsubchart'

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/charts/subchart1/values.yaml

@@ -0,0 +1,7 @@
+global:
+    key3: from subchart 1
+    key4:
+      key41: from subchart 1
+        
+subchart1Key: 'subchart1'
+mainchartKey: from subchart 1

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/charts/subchart2/Chart.yaml

@@ -0,0 +1,3 @@
+description: A Helm chart for Kubernetes
+name: chart-globals-inspect-values-with-subcharts-subchart2
+version: 0.1.0

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/charts/subchart2/values.yaml

@@ -0,0 +1,6 @@
+global:
+    key1: from subchart 2
+    key6:
+      key61: from subchart 2
+        
+subchart2Key: 'subchart2'

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/expected.yml

@@ -0,0 +1,25 @@
+description: A Helm chart for Kubernetes
+name: chart-globals-inspect-values-with-subcharts
+version: 0.1.0
+
+---
+chart-globals-inspect-values-with-subcharts-subchart1:
+  chart-globals-inspect-values-with-subcharts-subchart1-subsubchart:
+    subsubchartKey: subsubchart
+  mainchartKey: from subchart 1
+  subchart1Key: subchart1
+chart-globals-inspect-values-with-subcharts-subchart2:
+  subchart2Key: subchart2
+global:
+  key1: from mainchart
+  key2:
+    key21: from mainchart
+  key3: from subchart 1
+  key4:
+    key41: from subchart 1
+  key5: from subsubchart
+  key6:
+    key61: from subchart 2
+mainchartKey: foo
+
+---

cmd/helm/testdata/testcharts/chart-globals-inspect-values-with-subcharts/values.yaml

@@ -0,0 +1,6 @@
+global:
+    key1: from mainchart
+    key2:
+      key21: from mainchart
+
+mainchartKey: 'foo'

docs/helm/helm_inspect_values.md

@@ -26,6 +26,7 @@ helm inspect values [CHART]
       --username string    chart repository username where to locate the requested chart
       --verify             verify the provenance data for this chart
       --version string     version of the chart. By default, the newest chart is shown
+      --with-subcharts     recursively merges values.yaml files of this chart and all of its subcharts
 ```
 
 ### Options inherited from parent commands
@@ -42,4 +43,4 @@ helm inspect values [CHART]
 ### SEE ALSO
 * [helm inspect](helm_inspect.md)	 - inspect a chart
 
-###### Auto generated by spf13/cobra on 8-Mar-2018
+###### Auto generated by spf13/cobra on 24-Apr-2018