traefik/provider/docker/labels.go
Ludovic Fernandez 4bdeb33ac1 Docker labels
2017-11-28 11:16:03 +01:00

198 lines
5.9 KiB
Go

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
}