Segment labels: Docker

provider/label/segment.go

@@ -0,0 +1,167 @@
+package label
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/containous/traefik/log"
+)
+
+var (
+	// SegmentPropertiesRegexp used to extract the name of the segment and the name of the property for this segment
+	// All properties are under the format traefik.<segment_name>.frontend.*= except the port/portIndex/weight/protocol/backend directly after traefik.<segment_name>.
+	SegmentPropertiesRegexp = regexp.MustCompile(`^traefik\.(?P<segment_name>.+?)\.(?P<property_name>port|portIndex|weight|protocol|backend|frontend\.(.+))$`)
+
+	// PortRegexp used to extract the port label of the segment
+	PortRegexp = regexp.MustCompile(`^traefik\.(?P<segment_name>.+?)\.port$`)
+)
+
+// SegmentPropertyValues is a map of segment properties
+// an example value is: weight=42
+type SegmentPropertyValues map[string]string
+
+// SegmentProperties is a map of segment properties per segment,
+// which we can get with label[segmentName][propertyName].
+// It yields a property value.
+type SegmentProperties map[string]SegmentPropertyValues
+
+// FindSegmentSubmatch split segment labels
+func FindSegmentSubmatch(name string) []string {
+	matches := SegmentPropertiesRegexp.FindStringSubmatch(name)
+	if matches == nil ||
+		strings.HasPrefix(name, TraefikFrontend+".") ||
+		strings.HasPrefix(name, TraefikBackend+".") {
+		return nil
+	}
+	return matches
+}
+
+// ExtractServicePropertiesP Extract services labels
+// Deprecated
+func ExtractServicePropertiesP(labels *map[string]string) SegmentProperties {
+	if labels == nil {
+		return make(SegmentProperties)
+	}
+	return ExtractServiceProperties(*labels)
+}
+
+// ExtractServiceProperties Extract services labels
+// Deprecated
+func ExtractServiceProperties(labels map[string]string) SegmentProperties {
+	v := make(SegmentProperties)
+
+	for name, value := range labels {
+		matches := FindSegmentSubmatch(name)
+		if matches == nil {
+			continue
+		}
+
+		var segmentName string
+		var propertyName string
+		for i, name := range SegmentPropertiesRegexp.SubexpNames() {
+			// the group 0 is anonymous because it's always the root expression
+			if i != 0 {
+				if name == "segment_name" {
+					segmentName = matches[i]
+				} else if name == "property_name" {
+					propertyName = matches[i]
+				}
+			}
+		}
+
+		if _, ok := v[segmentName]; !ok {
+			v[segmentName] = make(SegmentPropertyValues)
+		}
+		v[segmentName][propertyName] = value
+	}
+
+	return v
+}
+
+// GetServiceLabel converts a key value of Label*, given a serviceName,
+// into a pattern <LabelPrefix>.<serviceName>.<property>
+// i.e. For LabelFrontendRule and serviceName=app it will return "traefik.app.frontend.rule"
+// Deprecated
+func GetServiceLabel(labelName, serviceName string) string {
+	if len(serviceName) > 0 {
+		property := strings.TrimPrefix(labelName, Prefix)
+		return Prefix + serviceName + "." + property
+	}
+	return labelName
+}
+
+// ExtractTraefikLabels transform labels to segment labels
+func ExtractTraefikLabels(originLabels map[string]string) SegmentProperties {
+	allLabels := make(SegmentProperties)
+
+	if _, ok := allLabels[""]; !ok {
+		allLabels[""] = make(SegmentPropertyValues)
+	}
+
+	for name, value := range originLabels {
+		if !strings.HasPrefix(name, Prefix) {
+			continue
+		}
+
+		matches := FindSegmentSubmatch(name)
+		if matches == nil {
+			// Classic labels
+			allLabels[""][name] = value
+		} else {
+			// segments labels
+			var segmentName string
+			var propertyName string
+			for i, name := range SegmentPropertiesRegexp.SubexpNames() {
+				// the group 0 is anonymous because it's always the root expression
+				if i != 0 {
+					if name == "segment_name" {
+						segmentName = matches[i]
+					} else if name == "property_name" {
+						propertyName = matches[i]
+					}
+				}
+			}
+
+			if _, ok := allLabels[segmentName]; !ok {
+				allLabels[segmentName] = make(SegmentPropertyValues)
+			}
+			allLabels[segmentName][Prefix+propertyName] = value
+		}
+	}
+	log.Debug(originLabels, allLabels)
+
+	allLabels.mergeDefault()
+
+	return allLabels
+}
+
+func (s SegmentProperties) mergeDefault() {
+	// if SegmentProperties contains the default segment, merge each segments with the default segment
+	if defaultLabels, okDefault := s[""]; okDefault {
+
+		segmentsNames := s.GetSegmentNames()
+		if len(defaultLabels) > 0 {
+			for _, name := range segmentsNames {
+				segmentLabels := s[name]
+				for key, value := range defaultLabels {
+					if _, ok := segmentLabels[key]; !ok {
+						segmentLabels[key] = value
+					}
+				}
+			}
+		}
+
+		if len(segmentsNames) > 1 {
+			delete(s, "")
+		}
+	}
+}
+
+// GetSegmentNames get all segment names
+func (s SegmentProperties) GetSegmentNames() []string {
+	var names []string
+	for name := range s {
+		names = append(names, name)
+	}
+	return names
+}