Docker labels

provider/docker/labels.go

@@ -0,0 +1,198 @@
+package docker
+
+import (
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/containous/traefik/log"
+	"github.com/containous/traefik/provider"
+	"github.com/containous/traefik/types"
+)
+
+const (
+	labelDockerNetwork            = "traefik.docker.network"
+	labelBackendLoadBalancerSwarm = "traefik.backend.loadbalancer.swarm"
+	labelDockerComposeProject     = "com.docker.compose.project"
+	labelDockerComposeService     = "com.docker.compose.service"
+)
+
+// Map of services properties
+// we can get it with label[serviceName][propertyName] and we got the propertyValue
+type labelServiceProperties map[string]map[string]string
+
+// Label functions
+
+func getFuncInt64Label(labelName string, defaultValue int64) func(container dockerData) int64 {
+	return func(container dockerData) int64 {
+		if label, err := getLabel(container, labelName); err == nil {
+			i, errConv := strconv.ParseInt(label, 10, 64)
+			if errConv != nil {
+				log.Errorf("Unable to parse traefik.backend.maxconn.amount %s", label)
+				return math.MaxInt64
+			}
+			return i
+		}
+		return defaultValue
+	}
+}
+
+func getFuncMapLabel(labelName string) func(container dockerData) map[string]string {
+	return func(container dockerData) map[string]string {
+		return parseMapLabel(container, labelName)
+	}
+}
+
+func parseMapLabel(container dockerData, labelName string) map[string]string {
+	customHeaders := make(map[string]string)
+	if label, err := getLabel(container, labelName); err == nil {
+		for _, headers := range strings.Split(label, ",") {
+			pair := strings.Split(headers, ":")
+			if len(pair) != 2 {
+				log.Warnf("Could not load header %q: %v, skipping...", labelName, pair)
+			} else {
+				customHeaders[pair[0]] = pair[1]
+			}
+		}
+	}
+	if len(customHeaders) == 0 {
+		log.Errorf("Could not load %q", labelName)
+	}
+	return customHeaders
+}
+
+func getFuncStringLabel(label string, defaultValue string) func(container dockerData) string {
+	return func(container dockerData) string {
+		return getStringLabel(container, label, defaultValue)
+	}
+}
+
+func getStringLabel(container dockerData, label string, defaultValue string) string {
+	if lbl, err := getLabel(container, label); err == nil {
+		return lbl
+	}
+	return defaultValue
+}
+
+func getFuncBoolLabel(label string) func(container dockerData) bool {
+	return func(container dockerData) bool {
+		return getBoolLabel(container, label)
+	}
+}
+
+func getBoolLabel(container dockerData, label string) bool {
+	lbl, err := getLabel(container, label)
+	return err == nil && len(lbl) > 0 && strings.EqualFold(strings.TrimSpace(lbl), "true")
+}
+
+func getFuncSliceStringLabel(label string) func(container dockerData) []string {
+	return func(container dockerData) []string {
+		return getSliceStringLabel(container, label)
+	}
+}
+
+func getSliceStringLabel(container dockerData, labelName string) []string {
+	var value []string
+
+	if label, err := getLabel(container, labelName); err == nil {
+		value = provider.SplitAndTrimString(label)
+	}
+
+	if len(value) == 0 {
+		log.Debugf("Could not load %v labels", labelName)
+	}
+	return value
+}
+
+// Service label functions
+
+func getFuncServiceSliceStringLabel(labelSuffix string) func(container dockerData, serviceName string) []string {
+	return func(container dockerData, serviceName string) []string {
+		return getServiceSliceStringLabel(container, serviceName, labelSuffix)
+	}
+}
+
+func getServiceSliceStringLabel(container dockerData, serviceName string, labelSuffix string) []string {
+	if value, ok := getContainerServiceLabel(container, serviceName, labelSuffix); ok {
+		return strings.Split(value, ",")
+	}
+	return getSliceStringLabel(container, types.LabelPrefix+labelSuffix)
+}
+
+func getFuncServiceStringLabel(labelSuffix string, defaultValue string) func(container dockerData, serviceName string) string {
+	return func(container dockerData, serviceName string) string {
+		return getServiceStringLabel(container, serviceName, labelSuffix, defaultValue)
+	}
+}
+
+func getServiceStringLabel(container dockerData, serviceName string, labelSuffix string, defaultValue string) string {
+	if value, ok := getContainerServiceLabel(container, serviceName, labelSuffix); ok {
+		return value
+	}
+	return getStringLabel(container, types.LabelPrefix+labelSuffix, defaultValue)
+}
+
+// Base functions
+
+// Gets the entry for a service label searching in all labels of the given container
+func getContainerServiceLabel(container dockerData, serviceName string, entry string) (string, bool) {
+	value, ok := extractServicesLabels(container.Labels)[serviceName][entry]
+	return value, ok
+}
+
+// Extract the service labels from container labels of dockerData struct
+func extractServicesLabels(labels map[string]string) labelServiceProperties {
+	v := make(labelServiceProperties)
+
+	for index, serviceProperty := range labels {
+		matches := servicesPropertiesRegexp.FindStringSubmatch(index)
+		if matches != nil {
+			result := make(map[string]string)
+			for i, name := range servicesPropertiesRegexp.SubexpNames() {
+				if i != 0 {
+					result[name] = matches[i]
+				}
+			}
+			serviceName := result["service_name"]
+			if _, ok := v[serviceName]; !ok {
+				v[serviceName] = make(map[string]string)
+			}
+			v[serviceName][result["property_name"]] = serviceProperty
+		}
+	}
+
+	return v
+}
+
+func hasLabel(label string) func(container dockerData) bool {
+	return func(container dockerData) bool {
+		lbl, err := getLabel(container, label)
+		return err == nil && len(lbl) > 0
+	}
+}
+
+func getLabel(container dockerData, label string) (string, error) {
+	for key, value := range container.Labels {
+		if key == label {
+			return value, nil
+		}
+	}
+	return "", fmt.Errorf("label not found: %s", label)
+}
+
+func getLabels(container dockerData, labels []string) (map[string]string, error) {
+	var globalErr error
+	foundLabels := map[string]string{}
+	for _, label := range labels {
+		foundLabel, err := getLabel(container, label)
+		// Error out only if one of them is defined.
+		if err != nil {
+			globalErr = fmt.Errorf("label not found: %s", label)
+			continue
+		}
+		foundLabels[label] = foundLabel
+
+	}
+	return foundLabels, globalErr
+}