Move code to pkg

pkg/server/cookie/cookie.go

@@ -0,0 +1,57 @@
+package cookie
+
+import (
+	"crypto/sha1"
+	"fmt"
+	"strings"
+
+	"github.com/containous/traefik/pkg/log"
+)
+
+const cookieNameLength = 6
+
+// GetName of a cookie
+func GetName(cookieName string, backendName string) string {
+	if len(cookieName) != 0 {
+		return sanitizeName(cookieName)
+	}
+
+	return GenerateName(backendName)
+}
+
+// GenerateName Generate a hashed name
+func GenerateName(backendName string) string {
+	data := []byte("_TRAEFIK_BACKEND_" + backendName)
+
+	hash := sha1.New()
+	_, err := hash.Write(data)
+	if err != nil {
+		// Impossible case
+		log.Errorf("Fail to create cookie name: %v", err)
+	}
+
+	return fmt.Sprintf("_%x", hash.Sum(nil))[:cookieNameLength]
+}
+
+// sanitizeName According to [RFC 2616](https://www.ietf.org/rfc/rfc2616.txt) section 2.2
+func sanitizeName(backend string) string {
+	sanitizer := func(r rune) rune {
+		switch r {
+		case '!', '#', '$', '%', '&', '\'', '*', '+', '-', '.', '^', '`', '|', '~':
+			return r
+		}
+
+		switch {
+		case 'a' <= r && r <= 'z':
+			fallthrough
+		case 'A' <= r && r <= 'Z':
+			fallthrough
+		case '0' <= r && r <= '9':
+			return r
+		default:
+			return '_'
+		}
+	}
+
+	return strings.Map(sanitizer, backend)
+}

pkg/server/cookie/cookie_test.go

@@ -0,0 +1,83 @@
+package cookie
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetName(t *testing.T) {
+	testCases := []struct {
+		desc               string
+		cookieName         string
+		backendName        string
+		expectedCookieName string
+	}{
+		{
+			desc:               "with backend name, without cookie name",
+			cookieName:         "",
+			backendName:        "/my/BACKEND-v1.0~rc1",
+			expectedCookieName: "_5f7bc",
+		},
+		{
+			desc:               "without backend name, with cookie name",
+			cookieName:         "/my/BACKEND-v1.0~rc1",
+			backendName:        "",
+			expectedCookieName: "_my_BACKEND-v1.0~rc1",
+		},
+		{
+			desc:               "with backend name, with cookie name",
+			cookieName:         "containous",
+			backendName:        "treafik",
+			expectedCookieName: "containous",
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			cookieName := GetName(test.cookieName, test.backendName)
+
+			assert.Equal(t, test.expectedCookieName, cookieName)
+		})
+	}
+}
+
+func Test_sanitizeName(t *testing.T) {
+	testCases := []struct {
+		desc         string
+		srcName      string
+		expectedName string
+	}{
+		{
+			desc:         "with /",
+			srcName:      "/my/BACKEND-v1.0~rc1",
+			expectedName: "_my_BACKEND-v1.0~rc1",
+		},
+		{
+			desc:         "some chars",
+			srcName:      "!#$%&'()*+-./:<=>?@[]^_`{|}~",
+			expectedName: "!#$%&'__*+-._________^_`_|_~",
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			cookieName := sanitizeName(test.srcName)
+
+			assert.Equal(t, test.expectedName, cookieName, "Cookie name")
+		})
+	}
+}
+
+func TestGenerateName(t *testing.T) {
+	cookieName := GenerateName("containous")
+
+	assert.Len(t, "_8a7bc", 6)
+	assert.Equal(t, "_8a7bc", cookieName)
+}