Add support for temporal and permanent redirects

core/pkg/ingress/annotations/redirect/redirect.go

@@ -0,0 +1,131 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package redirect
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+
+	extensions "k8s.io/api/extensions/v1beta1"
+
+	"k8s.io/ingress/core/pkg/ingress/annotations/parser"
+	"k8s.io/ingress/core/pkg/ingress/errors"
+)
+
+const (
+	permanent = "ingress.kubernetes.io/permanent-redirect"
+	temporal  = "ingress.kubernetes.io/temporal-redirect"
+	www       = "ingress.kubernetes.io/from-to-www-redirect"
+)
+
+// Redirect returns the redirect configuration for an Ingress rule
+type Redirect struct {
+	URL       string `json:"url"`
+	Code      int    `json:"code"`
+	FromToWWW bool   `json:"fromToWWW"`
+}
+
+type redirect struct{}
+
+// NewParser creates a new redirect annotation parser
+func NewParser() parser.IngressAnnotation {
+	return redirect{}
+}
+
+// Parse parses the annotations contained in the ingress
+// rule used to create a redirect in the paths defined in the rule.
+// If the Ingress containes both annotations the execution order is
+// temporal and then permanent
+func (a redirect) Parse(ing *extensions.Ingress) (interface{}, error) {
+	r3w, _ := parser.GetBoolAnnotation(www, ing)
+
+	tr, err := parser.GetStringAnnotation(temporal, ing)
+	if err != nil && !errors.IsMissingAnnotations(err) {
+		return nil, err
+	}
+
+	if tr != "" {
+		if err := isValidURL(tr); err != nil {
+			return nil, err
+		}
+
+		return &Redirect{
+			URL:       tr,
+			Code:      http.StatusFound,
+			FromToWWW: r3w,
+		}, nil
+	}
+
+	pr, err := parser.GetStringAnnotation(permanent, ing)
+	if err != nil && !errors.IsMissingAnnotations(err) {
+		return nil, err
+	}
+
+	if pr != "" {
+		if err := isValidURL(pr); err != nil {
+			return nil, err
+		}
+
+		return &Redirect{
+			URL:       pr,
+			Code:      http.StatusMovedPermanently,
+			FromToWWW: r3w,
+		}, nil
+	}
+
+	if r3w {
+		return &Redirect{
+			FromToWWW: r3w,
+		}, nil
+	}
+
+	return nil, errors.ErrMissingAnnotations
+}
+
+// Equal tests for equality between two Redirect types
+func (r1 *Redirect) Equal(r2 *Redirect) bool {
+	if r1 == r2 {
+		return true
+	}
+	if r1 == nil || r2 == nil {
+		return false
+	}
+	if r1.URL != r2.URL {
+		return false
+	}
+	if r1.Code != r2.Code {
+		return false
+	}
+	if r1.FromToWWW != r2.FromToWWW {
+		return false
+	}
+	return true
+}
+
+func isValidURL(s string) error {
+	u, err := url.Parse(s)
+	if err != nil {
+		return err
+	}
+
+	if !strings.HasPrefix(u.Scheme, "http") {
+		return errors.Errorf("only http and https are valid protocols (%v)", u.Scheme)
+	}
+
+	return nil
+}