better map merge

cmd/dkl-dir2config/render-context.go

@@ -41,11 +41,11 @@ func newRenderContext(host *clustersconfig.Host, cfg *clustersconfig.Config) (ct
 		group.Vars,
 		host.Vars,
 	} {
-		for k, v := range oVars {
-			vars[k] = v
-		}
+		mapMerge(vars, oVars)
 	}
 
+	log.Print("vars: ", vars)
+
 	return &renderContext{
 		Host:               host,
 		Group:              group,
@@ -58,6 +58,19 @@ func newRenderContext(host *clustersconfig.Host, cfg *clustersconfig.Config) (ct
 	}, nil
 }
 
+func mapMerge(target, source map[string]interface{}) {
+	for k, v := range source {
+		if tMap, targetIsMap := target[k].(map[string]interface{}); targetIsMap {
+			if sMap, sourceIsMap := v.(map[string]interface{}); sourceIsMap {
+				mapMerge(tMap, sMap)
+				continue
+			}
+		}
+
+		target[k] = v
+	}
+}
+
 func (ctx *renderContext) Config() string {
 	if ctx.ConfigTemplate == nil {
 		log.Fatalf("no such config: %q", ctx.Group.Config)