Support template as raw string.

provider/provider.go

@@ -52,10 +52,6 @@ func (p *BaseProvider) MatchConstraints(tags []string) (bool, *types.Constraint)
 
 // GetConfiguration return the provider configuration using templating
 func (p *BaseProvider) GetConfiguration(defaultTemplateFile string, funcMap template.FuncMap, templateObjects interface{}) (*types.Configuration, error) {
-	var (
-		buf []byte
-		err error
-	)
 	configuration := new(types.Configuration)
 
 	var defaultFuncMap = sprig.TxtFuncMap()
@@ -68,18 +64,13 @@ func (p *BaseProvider) GetConfiguration(defaultTemplateFile string, funcMap temp
 	}
 
 	tmpl := template.New(p.Filename).Funcs(defaultFuncMap)
-	if len(p.Filename) > 0 {
+
-		buf, err = ioutil.ReadFile(p.Filename)
+	tmplContent, err := p.getTemplateContent(defaultTemplateFile)
-		if err != nil {
+	if err != nil {
-			return nil, err
+		return nil, err
-		}
-	} else {
-		buf, err = autogen.Asset(defaultTemplateFile)
-		if err != nil {
-			return nil, err
-		}
 	}
-	_, err = tmpl.Parse(string(buf))
+
+	_, err = tmpl.Parse(tmplContent)
 	if err != nil {
 		return nil, err
 	}
@@ -100,6 +91,26 @@ func (p *BaseProvider) GetConfiguration(defaultTemplateFile string, funcMap temp
 	return configuration, nil
 }
 
+func (p *BaseProvider) getTemplateContent(defaultTemplateFile string) (string, error) {
+	if len(p.Filename) > 0 {
+		buf, err := ioutil.ReadFile(p.Filename)
+		if err != nil {
+			return "", err
+		}
+		return string(buf), nil
+	}
+
+	if strings.HasSuffix(defaultTemplateFile, ".tmpl") {
+		buf, err := autogen.Asset(defaultTemplateFile)
+		if err != nil {
+			return "", err
+		}
+		return string(buf), nil
+	}
+
+	return defaultTemplateFile, nil
+}
+
 func split(sep, s string) []string {
 	return strings.Split(s, sep)
 }

provider/provider_test.go

@@ -8,6 +8,8 @@ import (
 	"text/template"
 
 	"github.com/containous/traefik/types"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 type myProvider struct {
@@ -431,3 +433,42 @@ func TestSprigFunctions(t *testing.T) {
 		t.Fatal("Frontend frontend-1 should exists, but it not")
 	}
 }
+
+func TestBaseProvider_GetConfiguration(t *testing.T) {
+	baseProvider := BaseProvider{}
+
+	testCases := []struct {
+		name                string
+		defaultTemplateFile string
+		expectedContent     string
+	}{
+		{
+			defaultTemplateFile: "templates/docker.tmpl",
+			expectedContent:     readTemplateFile(t, "./../templates/docker.tmpl"),
+		},
+		{
+			defaultTemplateFile: `template content`,
+			expectedContent:     `template content`,
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+
+			content, err := baseProvider.getTemplateContent(test.defaultTemplateFile)
+			require.NoError(t, err)
+
+			assert.Equal(t, test.expectedContent, content)
+		})
+	}
+}
+
+func readTemplateFile(t *testing.T, path string) string {
+	t.Helper()
+	expectedContent, err := ioutil.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(expectedContent)
+}