feat(docker): add error pages labels.

provider/label/label.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/containous/traefik/log"
+	"github.com/containous/traefik/types"
 )
 
 const (
@@ -30,12 +31,20 @@ const (
 	DefaultBackendHealthCheckPort                  = 0
 )
 
-// ServicesPropertiesRegexp used to extract the name of the service and the name of the property for this service
-// All properties are under the format traefik.<servicename>.frontend.*= except the port/portIndex/weight/protocol/backend directly after traefik.<servicename>.
-var ServicesPropertiesRegexp = regexp.MustCompile(`^traefik\.(?P<service_name>.+?)\.(?P<property_name>port|portIndex|weight|protocol|backend|frontend\.(.+))$`)
+var (
+	// ServicesPropertiesRegexp used to extract the name of the service and the name of the property for this service
+	// All properties are under the format traefik.<servicename>.frontend.*= except the port/portIndex/weight/protocol/backend directly after traefik.<servicename>.
+	ServicesPropertiesRegexp = regexp.MustCompile(`^traefik\.(?P<service_name>.+?)\.(?P<property_name>port|portIndex|weight|protocol|backend|frontend\.(.+))$`)
 
-// PortRegexp used to extract the port label of the service
-var PortRegexp = regexp.MustCompile(`^traefik\.(?P<service_name>.+?)\.port$`)
+	// PortRegexp used to extract the port label of the service
+	PortRegexp = regexp.MustCompile(`^traefik\.(?P<service_name>.+?)\.port$`)
+
+	// RegexpBaseFrontendErrorPage used to extract error pages from service's label
+	RegexpBaseFrontendErrorPage = regexp.MustCompile(`^frontend\.errors\.(?P<name>[^ .]+)\.(?P<field>[^ .]+)$`)
+
+	// RegexpFrontendErrorPage used to extract error pages from label
+	RegexpFrontendErrorPage = regexp.MustCompile(`^traefik\.frontend\.errors\.(?P<name>[^ .]+)\.(?P<field>[^ .]+)$`)
+)
 
 // ServicePropertyValues is a map of services properties
 // an example value is: weight=42
@@ -200,13 +209,23 @@ func HasP(labels *map[string]string, labelName string) bool {
 	return Has(*labels, labelName)
 }
 
+// HasPrefix Check if a value is associated to a less one label with a prefix
+func HasPrefix(labels map[string]string, prefix string) bool {
+	for name, value := range labels {
+		if strings.HasPrefix(name, prefix) && len(value) > 0 {
+			return true
+		}
+	}
+	return false
+}
+
 // ExtractServiceProperties Extract services labels
 func ExtractServiceProperties(labels map[string]string) ServiceProperties {
 	v := make(ServiceProperties)
 
 	for name, value := range labels {
 		matches := ServicesPropertiesRegexp.FindStringSubmatch(name)
-		if matches == nil {
+		if matches == nil || strings.HasPrefix(name, TraefikFrontend) {
 			continue
 		}
 
@@ -239,6 +258,43 @@ func ExtractServicePropertiesP(labels *map[string]string) ServiceProperties {
 	return ExtractServiceProperties(*labels)
 }
 
+// ParseErrorPages parse error pages to create ErrorPage struct
+func ParseErrorPages(labels map[string]string, labelPrefix string, labelRegex *regexp.Regexp) map[string]*types.ErrorPage {
+	errorPages := make(map[string]*types.ErrorPage)
+
+	for lblName, value := range labels {
+		if strings.HasPrefix(lblName, labelPrefix) {
+			submatch := labelRegex.FindStringSubmatch(lblName)
+			if len(submatch) != 3 {
+				log.Errorf("Invalid page error label: %s, sub-match: %v", lblName, submatch)
+				continue
+			}
+
+			pageName := submatch[1]
+
+			ep, ok := errorPages[pageName]
+			if !ok {
+				ep = &types.ErrorPage{}
+				errorPages[pageName] = ep
+			}
+
+			switch submatch[2] {
+			case SuffixErrorPageStatus:
+				ep.Status = SplitAndTrimString(value, ",")
+			case SuffixErrorPageQuery:
+				ep.Query = value
+			case SuffixErrorPageBackend:
+				ep.Backend = value
+			default:
+				log.Errorf("Invalid page error label: %s", lblName)
+				continue
+			}
+		}
+	}
+
+	return errorPages
+}
+
 // IsEnabled Check if a container is enabled in Træfik
 func IsEnabled(labels map[string]string, exposedByDefault bool) bool {
 	return GetBoolValue(labels, TraefikEnable, exposedByDefault)