package provider import ( "errors" "net/http" "strconv" "strings" "text/template" "time" "golang.org/x/net/context" "github.com/BurntSushi/ty/fun" log "github.com/Sirupsen/logrus" "github.com/cenkalti/backoff" "github.com/containous/traefik/safe" "github.com/containous/traefik/types" "github.com/containous/traefik/version" "github.com/docker/engine-api/client" dockertypes "github.com/docker/engine-api/types" eventtypes "github.com/docker/engine-api/types/events" "github.com/docker/engine-api/types/filters" "github.com/docker/go-connections/sockets" "github.com/vdemeester/docker-events" ) // DockerAPIVersion is a constant holding the version of the Docker API traefik will use const DockerAPIVersion string = "1.21" // Docker holds configurations of the Docker provider. type Docker struct { BaseProvider `mapstructure:",squash"` Endpoint string `description:"Docker server endpoint. Can be a tcp or a unix socket endpoint"` Domain string `description:"Default domain used"` TLS *ClientTLS `description:"Enable Docker TLS support"` ExposedByDefault bool `description:"Expose containers by default"` } func (provider *Docker) createClient() (client.APIClient, error) { var httpClient *http.Client httpHeaders := map[string]string{ "User-Agent": "Traefik " + version.Version, } if provider.TLS != nil { config, err := provider.TLS.CreateTLSConfig() if err != nil { return nil, err } tr := &http.Transport{ TLSClientConfig: config, } proto, addr, _, err := client.ParseHost(provider.Endpoint) if err != nil { return nil, err } sockets.ConfigureTransport(tr, proto, addr) httpClient = &http.Client{ Transport: tr, } } return client.NewClient(provider.Endpoint, DockerAPIVersion, httpClient, httpHeaders) } // Provide allows the provider to provide configurations to traefik // using the given configuration channel. func (provider *Docker) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints []types.Constraint) error { provider.Constraints = append(provider.Constraints, constraints...) // TODO register this routine in pool, and watch for stop channel safe.Go(func() { operation := func() error { var err error dockerClient, err := provider.createClient() if err != nil { log.Errorf("Failed to create a client for docker, error: %s", err) return err } ctx := context.Background() version, err := dockerClient.ServerVersion(ctx) log.Debugf("Docker connection established with docker %s (API %s)", version.Version, version.APIVersion) containers, err := listContainers(ctx, dockerClient) if err != nil { log.Errorf("Failed to list containers for docker, error %s", err) return err } configuration := provider.loadDockerConfig(containers) configurationChan <- types.ConfigMessage{ ProviderName: "docker", Configuration: configuration, } if provider.Watch { ctx, cancel := context.WithCancel(ctx) pool.Go(func(stop chan bool) { for { select { case <-stop: cancel() return } } }) f := filters.NewArgs() f.Add("type", "container") options := dockertypes.EventsOptions{ Filters: f, } eventHandler := events.NewHandler(events.ByAction) startStopHandle := func(m eventtypes.Message) { log.Debugf("Docker event received %+v", m) containers, err := listContainers(ctx, dockerClient) if err != nil { log.Errorf("Failed to list containers for docker, error %s", err) // Call cancel to get out of the monitor cancel() return } configuration := provider.loadDockerConfig(containers) if configuration != nil { configurationChan <- types.ConfigMessage{ ProviderName: "docker", Configuration: configuration, } } } eventHandler.Handle("start", startStopHandle) eventHandler.Handle("die", startStopHandle) errChan := events.MonitorWithHandler(ctx, dockerClient, options, eventHandler) if err := <-errChan; err != nil { return err } } return nil } notify := func(err error, time time.Duration) { log.Errorf("Docker connection error %+v, retrying in %s", err, time) } err := backoff.RetryNotify(operation, backoff.NewExponentialBackOff(), notify) if err != nil { log.Fatalf("Cannot connect to docker server %+v", err) } }) return nil } func (provider *Docker) loadDockerConfig(containersInspected []dockertypes.ContainerJSON) *types.Configuration { var DockerFuncMap = template.FuncMap{ "getBackend": provider.getBackend, "getIPAddress": provider.getIPAddress, "getPort": provider.getPort, "getWeight": provider.getWeight, "getDomain": provider.getDomain, "getProtocol": provider.getProtocol, "getPassHostHeader": provider.getPassHostHeader, "getPriority": provider.getPriority, "getEntryPoints": provider.getEntryPoints, "getFrontendRule": provider.getFrontendRule, "replace": replace, } // filter containers filteredContainers := fun.Filter(func(container dockertypes.ContainerJSON) bool { return provider.containerFilter(container, provider.ExposedByDefault) }, containersInspected).([]dockertypes.ContainerJSON) frontends := map[string][]dockertypes.ContainerJSON{} for _, container := range filteredContainers { frontendName := provider.getFrontendName(container) frontends[frontendName] = append(frontends[frontendName], container) } templateObjects := struct { Containers []dockertypes.ContainerJSON Frontends map[string][]dockertypes.ContainerJSON Domain string }{ filteredContainers, frontends, provider.Domain, } configuration, err := provider.getConfiguration("templates/docker.tmpl", DockerFuncMap, templateObjects) if err != nil { log.Error(err) } return configuration } func (provider *Docker) containerFilter(container dockertypes.ContainerJSON, exposedByDefaultFlag bool) bool { _, err := strconv.Atoi(container.Config.Labels["traefik.port"]) if len(container.NetworkSettings.Ports) == 0 && err != nil { log.Debugf("Filtering container without port and no traefik.port label %s", container.Name) return false } if len(container.NetworkSettings.Ports) > 1 && err != nil { log.Debugf("Filtering container with more than 1 port and no traefik.port label %s", container.Name) return false } if !isContainerEnabled(container, exposedByDefaultFlag) { log.Debugf("Filtering disabled container %s", container.Name) return false } constraintTags := strings.Split(container.Config.Labels["traefik.tags"], ",") if ok, failingConstraint := provider.MatchConstraints(constraintTags); !ok { if failingConstraint != nil { log.Debugf("Container %v pruned by '%v' constraint", container.Name, failingConstraint.String()) } return false } return true } func (provider *Docker) getFrontendName(container dockertypes.ContainerJSON) string { // Replace '.' with '-' in quoted keys because of this issue https://github.com/BurntSushi/toml/issues/78 return normalize(provider.getFrontendRule(container)) } // GetFrontendRule returns the frontend rule for the specified container, using // it's label. It returns a default one (Host) if the label is not present. func (provider *Docker) getFrontendRule(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.frontend.rule"); err == nil { return label } return "Host:" + provider.getSubDomain(container.Name) + "." + provider.Domain } func (provider *Docker) getBackend(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.backend"); err == nil { return label } return normalize(container.Name) } func (provider *Docker) getIPAddress(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.docker.network"); err == nil && label != "" { networks := container.NetworkSettings.Networks if networks != nil { network := networks[label] if network != nil { return network.IPAddress } } } // If net==host, quick n' dirty, we return 127.0.0.1 // This will work locally, but will fail with swarm. if container.HostConfig != nil && "host" == container.HostConfig.NetworkMode { return "127.0.0.1" } for _, network := range container.NetworkSettings.Networks { return network.IPAddress } return "" } func (provider *Docker) getPort(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.port"); err == nil { return label } for key := range container.NetworkSettings.Ports { return key.Port() } return "" } func (provider *Docker) getWeight(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.weight"); err == nil { return label } return "1" } func (provider *Docker) getDomain(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.domain"); err == nil { return label } return provider.Domain } func (provider *Docker) getProtocol(container dockertypes.ContainerJSON) string { if label, err := getLabel(container, "traefik.protocol"); err == nil { return label } return "http" } func (provider *Docker) getPassHostHeader(container dockertypes.ContainerJSON) string { if passHostHeader, err := getLabel(container, "traefik.frontend.passHostHeader"); err == nil { return passHostHeader } return "true" } func (provider *Docker) getPriority(container dockertypes.ContainerJSON) string { if priority, err := getLabel(container, "traefik.frontend.priority"); err == nil { return priority } return "0" } func (provider *Docker) getEntryPoints(container dockertypes.ContainerJSON) []string { if entryPoints, err := getLabel(container, "traefik.frontend.entryPoints"); err == nil { return strings.Split(entryPoints, ",") } return []string{} } func isContainerEnabled(container dockertypes.ContainerJSON, exposedByDefault bool) bool { return exposedByDefault && container.Config.Labels["traefik.enable"] != "false" || container.Config.Labels["traefik.enable"] == "true" } func getLabel(container dockertypes.ContainerJSON, label string) (string, error) { for key, value := range container.Config.Labels { if key == label { return value, nil } } return "", errors.New("Label not found:" + label) } func getLabels(container dockertypes.ContainerJSON, 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 = errors.New("Label not found: " + label) continue } foundLabels[label] = foundLabel } return foundLabels, globalErr } func listContainers(ctx context.Context, dockerClient client.ContainerAPIClient) ([]dockertypes.ContainerJSON, error) { containerList, err := dockerClient.ContainerList(ctx, dockertypes.ContainerListOptions{}) if err != nil { return []dockertypes.ContainerJSON{}, err } containersInspected := []dockertypes.ContainerJSON{} // get inspect containers for _, container := range containerList { containerInspected, err := dockerClient.ContainerInspect(ctx, container.ID) if err != nil { log.Warnf("Failed to inspect container %s, error: %s", container.ID, err) } else { containersInspected = append(containersInspected, containerInspected) } } return containersInspected, nil } // Escape beginning slash "/", convert all others to dash "-" func (provider *Docker) getSubDomain(name string) string { return strings.Replace(strings.TrimPrefix(name, "/"), "/", "-", -1) }