From 89f64183cb90491bd62b9d887dbe21a6991f2b2b Mon Sep 17 00:00:00 2001
From: Withnale <withnale@gmx.com>
Date: Sat, 9 Dec 2017 17:54:41 +0000
Subject: [PATCH] Added support for export-values in requirements

---
 cmd/helm/template.go                          |  4 ++
 pkg/chartutil/requirements.go                 | 67 +++++++++++++++++++
 pkg/chartutil/requirements_test.go            |  8 +++
 .../testdata/subpop/requirements.yaml         |  3 +
 4 files changed, 82 insertions(+)

diff --git a/cmd/helm/template.go b/cmd/helm/template.go
index 3ca364cfb..f09d28a4c 100644
--- a/cmd/helm/template.go
+++ b/cmd/helm/template.go
@@ -186,6 +186,10 @@ func (t *templateCmd) run(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
+	err = chartutil.ProcessRequirementsExportValues(c)
+	if err != nil {
+		return err
+	}
 
 	// Set up engine.
 	renderer := engine.New()
diff --git a/pkg/chartutil/requirements.go b/pkg/chartutil/requirements.go
index ce761a6fc..dcd13de0e 100644
--- a/pkg/chartutil/requirements.go
+++ b/pkg/chartutil/requirements.go
@@ -66,6 +66,9 @@ type Dependency struct {
 	// ImportValues holds the mapping of source values to parent key to be imported. Each item can be a
 	// string or pair of child/parent sublist items.
 	ImportValues []interface{} `json:"import-values,omitempty"`
+	// ExportValues holds the mapping of source values to parent key to be exported. Each item can be a
+	// string or pair of child/parent sublist items.
+	ExportValues []interface{} `json:"export-values,omitempty"`
 	// Alias usable alias to be used for the chart
 	Alias string `json:"alias,omitempty"`
 }
@@ -445,6 +448,60 @@ func processImportValues(c *chart.Chart) error {
 	return nil
 }
 
+// processImportValues merges values from child to parent based on the chart's dependencies' ImportValues field.
+func processExportValues(c *chart.Chart) error {
+	reqs, err := LoadRequirements(c)
+	if err != nil {
+		return err
+	}
+	// combine chart values and empty config to get Values
+	cvals, err := CoalesceValues(c, &chart.Config{})
+	if err != nil {
+		return err
+	}
+	b := make(map[string]interface{}, 0)
+	// import values from each dependency if specified in import-values
+	for _, r := range reqs.Dependencies {
+		if len(r.ExportValues) > 0 {
+			var outiv []interface{}
+			for _, riv := range r.ExportValues {
+				iv := riv.(map[string]interface{})
+				nm := map[string]string{
+					"child":  iv["child"].(string),
+					"parent": iv["parent"].(string),
+				}
+				outiv = append(outiv, nm)
+				s := nm["parent"]
+				// get child table
+				vv, err := cvals.Table(s)
+				if err != nil {
+					log.Printf("Warning: ExportValues missing table: %v", err)
+					continue
+				}
+				name := r.Name
+				if r.Alias != "" {
+					name = r.Alias
+				}
+				// create value map from child to be merged into parent
+				vm := pathToMap(name+"."+nm["child"], vv.AsMap())
+				b = coalesceTables(cvals, vm)
+			}
+			// set our formatted import values
+			r.ExportValues = outiv
+		}
+	}
+	b = coalesceTables(b, cvals)
+	y, err := yaml.Marshal(b)
+	if err != nil {
+		return err
+	}
+
+	// set the new values
+	c.Values = &chart.Config{Raw: string(y)}
+
+	return nil
+}
+
 // ProcessRequirementsImportValues imports specified chart values from child to parent.
 func ProcessRequirementsImportValues(c *chart.Chart) error {
 	pc := getParents(c, nil)
@@ -454,3 +511,13 @@ func ProcessRequirementsImportValues(c *chart.Chart) error {
 
 	return nil
 }
+
+// ProcessRequirementsExportValues exports specified chart values from parent to child.
+func ProcessRequirementsExportValues(c *chart.Chart) error {
+	pc := getParents(c, nil)
+	for i := len(pc) - 1; i >= 0; i-- {
+		processExportValues(pc[i])
+	}
+
+	return nil
+}
diff --git a/pkg/chartutil/requirements_test.go b/pkg/chartutil/requirements_test.go
index 24388f86c..c1378d8d2 100644
--- a/pkg/chartutil/requirements_test.go
+++ b/pkg/chartutil/requirements_test.go
@@ -279,6 +279,10 @@ func TestProcessRequirementsImportValues(t *testing.T) {
 	e["SCBexported2A"] = "blaster"
 	e["global.SC1exported2.all.SC1exported3"] = "SC1expstr"
 
+	// `imports`
+	e["subchart1.mytags.back-end"] = "false"
+	e["subchart1.mytags.front-end"] = "true"
+
 	verifyRequirementsImportValues(t, c, v, e)
 }
 func verifyRequirementsImportValues(t *testing.T, c *chart.Chart, v *chart.Config, e map[string]string) {
@@ -287,6 +291,10 @@ func verifyRequirementsImportValues(t *testing.T, c *chart.Chart, v *chart.Confi
 	if err != nil {
 		t.Errorf("Error processing import values requirements %v", err)
 	}
+	err = ProcessRequirementsExportValues(c)
+	if err != nil {
+		t.Errorf("Error processing import values requirements %v", err)
+	}
 	cv := c.GetValues()
 	cc, err := ReadValues([]byte(cv.Raw))
 	if err != nil {
diff --git a/pkg/chartutil/testdata/subpop/requirements.yaml b/pkg/chartutil/testdata/subpop/requirements.yaml
index a8eb0aace..7104c7316 100644
--- a/pkg/chartutil/testdata/subpop/requirements.yaml
+++ b/pkg/chartutil/testdata/subpop/requirements.yaml
@@ -21,6 +21,9 @@ dependencies:
             parent: .
           - SCBexported2
           - SC1exported1
+        export-values:
+          - child: mytags
+            parent: tags
 
       - name: subchart2
         repository: http://localhost:10191