add a new example

_examples/configuration/multi-environments/api/configuration.go

@@ -0,0 +1,27 @@
+package api
+
+import (
+	"os"
+
+	"github.com/kataras/iris/v12"
+	"gopkg.in/yaml.v3"
+)
+
+type Configuration struct {
+	Host              string `yaml:"Host"`
+	Port              int    `yaml:"Port"`
+	EnableCompression bool   `yaml:"EnableCompression"`
+	AllowOrigin       string `yaml:"AllowOrigin"`
+	// Iris specific configuration.
+	Iris iris.Configuration `yaml:"Iris"`
+}
+
+// BindFile binds the yaml file's contents to this Configuration.
+func (c *Configuration) BindFile(filename string) error {
+	contents, err := os.ReadFile(filename)
+	if err != nil {
+		return err
+	}
+
+	return yaml.Unmarshal(contents, c)
+}