Adding upstream version 0.8.9.

Signed-off-by: Daniel Baumann <daniel@debian.org>

pkg/services/standard/standard_templater.go

@@ -0,0 +1,45 @@
+package standard
+
+import (
+	"fmt"
+	"os"
+	"text/template"
+)
+
+// Templater is the standard implementation of ApplyTemplate using the "text/template" library.
+type Templater struct {
+	templates map[string]*template.Template
+}
+
+// GetTemplate attempts to retrieve the template identified with id.
+func (templater *Templater) GetTemplate(id string) (*template.Template, bool) {
+	tpl, found := templater.templates[id]
+
+	return tpl, found
+}
+
+// SetTemplateString creates a new template from the body and assigns it the id.
+func (templater *Templater) SetTemplateString(templateID string, body string) error {
+	tpl, err := template.New("").Parse(body)
+	if err != nil {
+		return fmt.Errorf("parsing template string for ID %q: %w", templateID, err)
+	}
+
+	if templater.templates == nil {
+		templater.templates = make(map[string]*template.Template, 1)
+	}
+
+	templater.templates[templateID] = tpl
+
+	return nil
+}
+
+// SetTemplateFile creates a new template from the file and assigns it the id.
+func (templater *Templater) SetTemplateFile(templateID string, file string) error {
+	bytes, err := os.ReadFile(file)
+	if err != nil {
+		return fmt.Errorf("reading template file %q for ID %q: %w", file, templateID, err)
+	}
+
+	return templater.SetTemplateString(templateID, string(bytes))
+}