Dynamic Configuration Refactoring

responsemodifiers/response_modifier.go

@@ -0,0 +1,51 @@
+package responsemodifiers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/containous/traefik/config"
+)
+
+// NewBuilder creates a builder.
+func NewBuilder(configs map[string]*config.Middleware) *Builder {
+	return &Builder{configs: configs}
+}
+
+// Builder holds builder configuration.
+type Builder struct {
+	configs map[string]*config.Middleware
+}
+
+// Build Builds the response modifier.
+func (f *Builder) Build(ctx context.Context, names []string) func(*http.Response) error {
+	var modifiers []func(*http.Response) error
+
+	for _, middleName := range names {
+		if conf, ok := f.configs[middleName]; ok {
+			if conf.Headers != nil {
+				getLogger(ctx, middleName, "Headers").Debug("Creating Middleware (ResponseModifier)")
+
+				modifiers = append(modifiers, buildHeaders(conf.Headers))
+			} else if conf.Chain != nil {
+				getLogger(ctx, middleName, "Chain").Debug("Creating Middleware (ResponseModifier)")
+
+				modifiers = append(modifiers, f.Build(ctx, conf.Chain.Middlewares))
+			}
+		}
+	}
+
+	if len(modifiers) > 0 {
+		return func(resp *http.Response) error {
+			for i := len(modifiers); i > 0; i-- {
+				err := modifiers[i-1](resp)
+				if err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+	}
+
+	return func(response *http.Response) error { return nil }
+}