configuration_render: add function to parser inner template blocks to a var

internal/pkg/rpaas/nginx/configuration_render.go

@@ -21,6 +21,8 @@ import (
 )
 
 var trimTrailingSpacesRegex = regexp.MustCompile(`[ \t]+?\n`)
+var nginxTemplate = &template.Template{}
+var errRenderInnerTemplate = fmt.Errorf("template contains renderInnerTemplate")
 
 type ConfigurationRenderer interface {
 	Render(ConfigurationData) (string, error)
@@ -58,39 +60,50 @@ func (r *rpaasConfigurationRenderer) Render(c ConfigurationData) (string, error)
 }
 
 func NewConfigurationRenderer(cb ConfigurationBlocks) (ConfigurationRenderer, error) {
-	tpl, err := defaultMainTemplate.Clone()
+	var err error
+	nginxTemplate, err = defaultMainTemplate.Clone()
 	if err != nil {
 		return nil, err
 	}
 
 	if cb.MainBlock != "" {
-		tpl, err = template.New("main").Funcs(templateFuncs).Parse(cb.MainBlock)
+		nginxTemplate, err = template.New("main").Funcs(templateFuncs).Parse(cb.MainBlock)
 		if err != nil {
 			return nil, err
 		}
 	}
 
-	if _, err = tpl.New("root").Parse(cb.RootBlock); err != nil {
+	if _, err = nginxTemplate.New("root").Parse(cb.RootBlock); err != nil {
 		return nil, err
 	}
 
-	if _, err = tpl.New("http").Parse(cb.HttpBlock); err != nil {
+	if _, err = nginxTemplate.New("http").Parse(cb.HttpBlock); err != nil {
 		return nil, err
 	}
 
-	if _, err = tpl.New("server").Parse(cb.ServerBlock); err != nil {
+	if _, err = nginxTemplate.New("server").Parse(cb.ServerBlock); err != nil {
 		return nil, err
 	}
 
-	if _, err = tpl.New("lua-server").Parse(cb.LuaServerBlock); err != nil {
+	if _, err = nginxTemplate.New("lua-server").Parse(cb.LuaServerBlock); err != nil {
 		return nil, err
 	}
 
-	if _, err = tpl.New("lua-worker").Parse(cb.LuaWorkerBlock); err != nil {
+	if _, err = nginxTemplate.New("lua-worker").Parse(cb.LuaWorkerBlock); err != nil {
 		return nil, err
 	}
 
-	return &rpaasConfigurationRenderer{t: tpl}, nil
+	return &rpaasConfigurationRenderer{t: nginxTemplate}, nil
+}
+
+func renderInnerTemplate(name string, nginx ConfigurationData) (string, error) {
+	tpl := nginxTemplate.Lookup(name)
+	parsedTemplate := tpl.Tree.Root.String()
+	if strings.Contains(parsedTemplate, "renderInnerTemplate") {
+		return "", errRenderInnerTemplate
+	}
+	r := &rpaasConfigurationRenderer{t: tpl}
+	return r.Render(nginx)
 }
 
 func buildLocationKey(prefix, path string) string {
@@ -232,6 +245,7 @@ func defaultCertificate(instance *v1alpha1.RpaasInstance) *nginxv1alpha1.NginxTL
 }
 
 var internalTemplateFuncs = template.FuncMap(map[string]interface{}{
+	"renderInnerTemplate":     renderInnerTemplate,
 	"boolValue":               v1alpha1.BoolValue,
 	"buildLocationKey":        buildLocationKey,
 	"hasRootPath":             hasRootPath,
@@ -282,6 +296,7 @@ var rawNginxConfiguration = `
 {{- $all := . -}}
 {{- $config := .Config -}}
 {{- $instance := .Instance -}}
+{{- $httpBlock := renderInnerTemplate "http" . -}}
 
 # This file was generated by RPaaS (https://github.com/tsuru/rpaas-operator.git)
 # Do not modify this file, any change will be lost.
@@ -437,7 +452,7 @@ http {
         {{ template "lua-worker" . }}
     }
 
-    {{ template "http" . }}
+    {{ $httpBlock }}
 
     server {
         listen {{ managePort $instance }};

internal/pkg/rpaas/nginx/configuration_render_test.go

@@ -21,10 +21,11 @@ func TestRpaasConfigurationRenderer_Render(t *testing.T) {
 	size300MB := resource.MustParse("300Mi")
 
 	tests := []struct {
-		name      string
-		blocks    ConfigurationBlocks
-		data      ConfigurationData
-		assertion func(*testing.T, string)
+		name          string
+		blocks        ConfigurationBlocks
+		data          ConfigurationData
+		assertion     func(*testing.T, string)
+		expectedError string
 	}{
 		{
 			name: "with false values",
@@ -271,6 +272,21 @@ func TestRpaasConfigurationRenderer_Render(t *testing.T) {
 				assert.Regexp(t, `\s# some custom conf at init_worker_by_lua_block context`, result)
 			},
 		},
+		{
+			name: "with invalid recursive renderInnnerTemplate inside config blocks",
+			blocks: ConfigurationBlocks{
+				RootBlock:      `# some custom conf at {{ "root" }} context`,
+				HttpBlock:      "# some custom conf at {{ $var := renderInnerTemplate \"http\" .}} context",
+				ServerBlock:    "# some custom conf at server context",
+				LuaServerBlock: "# some custom conf at init_by_lua_block context",
+				LuaWorkerBlock: "# some custom conf at init_worker_by_lua_block context",
+			},
+			data: ConfigurationData{
+				Config:   &v1alpha1.NginxConfig{},
+				Instance: &v1alpha1.RpaasInstance{},
+			},
+			expectedError: errRenderInnerTemplate.Error(),
+		},
 		{
 			name: "with app bound",
 			data: ConfigurationData{
@@ -602,6 +618,10 @@ func TestRpaasConfigurationRenderer_Render(t *testing.T) {
 			cr, err := NewConfigurationRenderer(tt.blocks)
 			require.NoError(t, err)
 			result, err := cr.Render(tt.data)
+			if tt.expectedError != "" {
+				assert.ErrorContains(t, err, tt.expectedError)
+				return
+			}
 			require.NoError(t, err)
 			tt.assertion(t, result)
 		})