package docker import ( "context" "errors" "fmt" "io" "net" "net/http" "strconv" "strings" "text/template" "time" "github.com/cenkalti/backoff/v4" "github.com/docker/cli/cli/connhelper" dockertypes "github.com/docker/docker/api/types" dockercontainertypes "github.com/docker/docker/api/types/container" eventtypes "github.com/docker/docker/api/types/events" "github.com/docker/docker/api/types/filters" networktypes "github.com/docker/docker/api/types/network" swarmtypes "github.com/docker/docker/api/types/swarm" "github.com/docker/docker/api/types/versions" "github.com/docker/docker/client" "github.com/docker/go-connections/nat" "github.com/docker/go-connections/sockets" ptypes "github.com/traefik/paerser/types" "github.com/traefik/traefik/v2/pkg/config/dynamic" "github.com/traefik/traefik/v2/pkg/job" "github.com/traefik/traefik/v2/pkg/log" "github.com/traefik/traefik/v2/pkg/provider" "github.com/traefik/traefik/v2/pkg/safe" "github.com/traefik/traefik/v2/pkg/types" "github.com/traefik/traefik/v2/pkg/version" ) const ( // DockerAPIVersion is a constant holding the version of the Provider API traefik will use. DockerAPIVersion = "1.24" // SwarmAPIVersion is a constant holding the version of the Provider API traefik will use. SwarmAPIVersion = "1.24" ) // DefaultTemplateRule The default template for the default rule. const DefaultTemplateRule = "Host(`{{ normalize .Name }}`)" var _ provider.Provider = (*Provider)(nil) // Provider holds configurations of the provider. type Provider struct { Constraints string `description:"Constraints is an expression that Traefik matches against the container's labels to determine whether to create any route for that container." json:"constraints,omitempty" toml:"constraints,omitempty" yaml:"constraints,omitempty" export:"true"` Watch bool `description:"Watch Docker events." json:"watch,omitempty" toml:"watch,omitempty" yaml:"watch,omitempty" export:"true"` Endpoint string `description:"Docker server endpoint. Can be a tcp or a unix socket endpoint." json:"endpoint,omitempty" toml:"endpoint,omitempty" yaml:"endpoint,omitempty"` DefaultRule string `description:"Default rule." json:"defaultRule,omitempty" toml:"defaultRule,omitempty" yaml:"defaultRule,omitempty"` TLS *types.ClientTLS `description:"Enable Docker TLS support." json:"tls,omitempty" toml:"tls,omitempty" yaml:"tls,omitempty" export:"true"` ExposedByDefault bool `description:"Expose containers by default." json:"exposedByDefault,omitempty" toml:"exposedByDefault,omitempty" yaml:"exposedByDefault,omitempty" export:"true"` UseBindPortIP bool `description:"Use the ip address from the bound port, rather than from the inner network." json:"useBindPortIP,omitempty" toml:"useBindPortIP,omitempty" yaml:"useBindPortIP,omitempty" export:"true"` SwarmMode bool `description:"Use Docker on Swarm Mode." json:"swarmMode,omitempty" toml:"swarmMode,omitempty" yaml:"swarmMode,omitempty" export:"true"` Network string `description:"Default Docker network used." json:"network,omitempty" toml:"network,omitempty" yaml:"network,omitempty" export:"true"` SwarmModeRefreshSeconds ptypes.Duration `description:"Polling interval for swarm mode." json:"swarmModeRefreshSeconds,omitempty" toml:"swarmModeRefreshSeconds,omitempty" yaml:"swarmModeRefreshSeconds,omitempty" export:"true"` HTTPClientTimeout ptypes.Duration `description:"Client timeout for HTTP connections." json:"httpClientTimeout,omitempty" toml:"httpClientTimeout,omitempty" yaml:"httpClientTimeout,omitempty" export:"true"` AllowEmptyServices bool `description:"Disregards the Docker containers health checks with respect to the creation or removal of the corresponding services." json:"allowEmptyServices,omitempty" toml:"allowEmptyServices,omitempty" yaml:"allowEmptyServices,omitempty" export:"true"` defaultRuleTpl *template.Template } // SetDefaults sets the default values. func (p *Provider) SetDefaults() { p.Watch = true p.ExposedByDefault = true p.Endpoint = "unix:///var/run/docker.sock" p.SwarmMode = false p.SwarmModeRefreshSeconds = ptypes.Duration(15 * time.Second) p.DefaultRule = DefaultTemplateRule } // Init the provider. func (p *Provider) Init() error { defaultRuleTpl, err := provider.MakeDefaultRuleTemplate(p.DefaultRule, nil) if err != nil { return fmt.Errorf("error while parsing default rule: %w", err) } p.defaultRuleTpl = defaultRuleTpl return nil } // dockerData holds the need data to the provider. type dockerData struct { ID string ServiceName string Name string Labels map[string]string // List of labels set to container or service NetworkSettings networkSettings Health string Node *dockertypes.ContainerNode ExtraConf configuration } // NetworkSettings holds the networks data to the provider. type networkSettings struct { NetworkMode dockercontainertypes.NetworkMode Ports nat.PortMap Networks map[string]*networkData } // Network holds the network data to the provider. type networkData struct { Name string Addr string Port int Protocol string ID string } func (p *Provider) createClient() (client.APIClient, error) { opts, err := p.getClientOpts() if err != nil { return nil, err } httpHeaders := map[string]string{ "User-Agent": "Traefik " + version.Version, } opts = append(opts, client.WithHTTPHeaders(httpHeaders)) apiVersion := DockerAPIVersion if p.SwarmMode { apiVersion = SwarmAPIVersion } opts = append(opts, client.WithVersion(apiVersion)) return client.NewClientWithOpts(opts...) } func (p *Provider) getClientOpts() ([]client.Opt, error) { helper, err := connhelper.GetConnectionHelper(p.Endpoint) if err != nil { return nil, err } // SSH if helper != nil { // https://github.com/docker/cli/blob/ebca1413117a3fcb81c89d6be226dcec74e5289f/cli/context/docker/load.go#L112-L123 httpClient := &http.Client{ Transport: &http.Transport{ DialContext: helper.Dialer, }, } return []client.Opt{ client.WithHTTPClient(httpClient), client.WithTimeout(time.Duration(p.HTTPClientTimeout)), client.WithHost(helper.Host), // To avoid 400 Bad Request: malformed Host header daemon error client.WithDialContext(helper.Dialer), }, nil } opts := []client.Opt{ client.WithHost(p.Endpoint), client.WithTimeout(time.Duration(p.HTTPClientTimeout)), } if p.TLS != nil { ctx := log.With(context.Background(), log.Str(log.ProviderName, "docker")) conf, err := p.TLS.CreateTLSConfig(ctx) if err != nil { return nil, fmt.Errorf("unable to create client TLS configuration: %w", err) } hostURL, err := client.ParseHostURL(p.Endpoint) if err != nil { return nil, err } tr := &http.Transport{ TLSClientConfig: conf, } if err := sockets.ConfigureTransport(tr, hostURL.Scheme, hostURL.Host); err != nil { return nil, err } opts = append(opts, client.WithHTTPClient(&http.Client{Transport: tr, Timeout: time.Duration(p.HTTPClientTimeout)})) } return opts, nil } // Provide allows the docker provider to provide configurations to traefik using the given configuration channel. func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.Pool) error { pool.GoCtx(func(routineCtx context.Context) { ctxLog := log.With(routineCtx, log.Str(log.ProviderName, "docker")) logger := log.FromContext(ctxLog) operation := func() error { var err error ctx, cancel := context.WithCancel(ctxLog) defer cancel() ctx = log.With(ctx, log.Str(log.ProviderName, "docker")) dockerClient, err := p.createClient() if err != nil { logger.Errorf("Failed to create a client for docker, error: %s", err) return err } defer dockerClient.Close() serverVersion, err := dockerClient.ServerVersion(ctx) if err != nil { logger.Errorf("Failed to retrieve information of the docker client and server host: %s", err) return err } logger.Debugf("Provider connection established with docker %s (API %s)", serverVersion.Version, serverVersion.APIVersion) var dockerDataList []dockerData if p.SwarmMode { dockerDataList, err = p.listServices(ctx, dockerClient) if err != nil { logger.Errorf("Failed to list services for docker swarm mode, error %s", err) return err } } else { dockerDataList, err = p.listContainers(ctx, dockerClient) if err != nil { logger.Errorf("Failed to list containers for docker, error %s", err) return err } } configuration := p.buildConfiguration(ctxLog, dockerDataList) configurationChan <- dynamic.Message{ ProviderName: "docker", Configuration: configuration, } if p.Watch { if p.SwarmMode { errChan := make(chan error) // TODO: This need to be change. Linked to Swarm events docker/docker#23827 ticker := time.NewTicker(time.Duration(p.SwarmModeRefreshSeconds)) pool.GoCtx(func(ctx context.Context) { ctx = log.With(ctx, log.Str(log.ProviderName, "docker")) logger := log.FromContext(ctx) defer close(errChan) for { select { case <-ticker.C: services, err := p.listServices(ctx, dockerClient) if err != nil { logger.Errorf("Failed to list services for docker swarm mode, error %s", err) errChan <- err return } configuration := p.buildConfiguration(ctx, services) if configuration != nil { configurationChan <- dynamic.Message{ ProviderName: "docker", Configuration: configuration, } } case <-ctx.Done(): ticker.Stop() return } } }) if err, ok := <-errChan; ok { return err } // channel closed } else { f := filters.NewArgs() f.Add("type", "container") options := eventtypes.ListOptions{ Filters: f, } startStopHandle := func(m eventtypes.Message) { logger.Debugf("Provider event received %+v", m) containers, err := p.listContainers(ctx, dockerClient) if err != nil { logger.Errorf("Failed to list containers for docker, error %s", err) // Call cancel to get out of the monitor return } configuration := p.buildConfiguration(ctx, containers) if configuration != nil { message := dynamic.Message{ ProviderName: "docker", Configuration: configuration, } select { case configurationChan <- message: case <-ctx.Done(): } } } eventsc, errc := dockerClient.Events(ctx, options) for { select { case event := <-eventsc: if event.Action == "start" || event.Action == "die" || strings.HasPrefix(string(event.Action), "health_status") { startStopHandle(event) } case err := <-errc: if errors.Is(err, io.EOF) { logger.Debug("Provider event stream closed") } return err case <-ctx.Done(): return nil } } } } return nil } notify := func(err error, time time.Duration) { logger.Errorf("Provider connection error %+v, retrying in %s", err, time) } err := backoff.RetryNotify(safe.OperationWithRecover(operation), backoff.WithContext(job.NewBackOff(backoff.NewExponentialBackOff()), ctxLog), notify) if err != nil { logger.Errorf("Cannot connect to docker server %+v", err) } }) return nil } func (p *Provider) listContainers(ctx context.Context, dockerClient client.ContainerAPIClient) ([]dockerData, error) { containerList, err := dockerClient.ContainerList(ctx, dockercontainertypes.ListOptions{}) if err != nil { return nil, err } var inspectedContainers []dockerData // get inspect containers for _, container := range containerList { dData := inspectContainers(ctx, dockerClient, container.ID) if len(dData.Name) == 0 { continue } extraConf, err := p.getConfiguration(dData) if err != nil { log.FromContext(ctx).Errorf("Skip container %s: %v", getServiceName(dData), err) continue } dData.ExtraConf = extraConf inspectedContainers = append(inspectedContainers, dData) } return inspectedContainers, nil } func inspectContainers(ctx context.Context, dockerClient client.ContainerAPIClient, containerID string) dockerData { containerInspected, err := dockerClient.ContainerInspect(ctx, containerID) if err != nil { log.FromContext(ctx).Warnf("Failed to inspect container %s, error: %s", containerID, err) return dockerData{} } // This condition is here to avoid to have empty IP https://github.com/traefik/traefik/issues/2459 // We register only container which are running if containerInspected.ContainerJSONBase != nil && containerInspected.ContainerJSONBase.State != nil && containerInspected.ContainerJSONBase.State.Running { return parseContainer(containerInspected) } return dockerData{} } func parseContainer(container dockertypes.ContainerJSON) dockerData { dData := dockerData{ NetworkSettings: networkSettings{}, } if container.ContainerJSONBase != nil { dData.ID = container.ContainerJSONBase.ID dData.Name = container.ContainerJSONBase.Name dData.ServiceName = dData.Name // Default ServiceName to be the container's Name. dData.Node = container.ContainerJSONBase.Node if container.ContainerJSONBase.HostConfig != nil { dData.NetworkSettings.NetworkMode = container.ContainerJSONBase.HostConfig.NetworkMode } if container.State != nil && container.State.Health != nil { dData.Health = container.State.Health.Status } } if container.Config != nil && container.Config.Labels != nil { dData.Labels = container.Config.Labels } if container.NetworkSettings != nil { if container.NetworkSettings.Ports != nil { dData.NetworkSettings.Ports = container.NetworkSettings.Ports } if container.NetworkSettings.Networks != nil { dData.NetworkSettings.Networks = make(map[string]*networkData) for name, containerNetwork := range container.NetworkSettings.Networks { addr := containerNetwork.IPAddress if addr == "" { addr = containerNetwork.GlobalIPv6Address } dData.NetworkSettings.Networks[name] = &networkData{ ID: containerNetwork.NetworkID, Name: name, Addr: addr, } } } } return dData } func (p *Provider) listServices(ctx context.Context, dockerClient client.APIClient) ([]dockerData, error) { logger := log.FromContext(ctx) serviceList, err := dockerClient.ServiceList(ctx, dockertypes.ServiceListOptions{}) if err != nil { return nil, err } serverVersion, err := dockerClient.ServerVersion(ctx) if err != nil { return nil, err } networkListArgs := filters.NewArgs() // https://docs.docker.com/engine/api/v1.29/#tag/Network (Docker 17.06) if versions.GreaterThanOrEqualTo(serverVersion.APIVersion, "1.29") { networkListArgs.Add("scope", "swarm") } else { networkListArgs.Add("driver", "overlay") } networkList, err := dockerClient.NetworkList(ctx, networktypes.ListOptions{Filters: networkListArgs}) if err != nil { logger.Debugf("Failed to network inspect on client for docker, error: %s", err) return nil, err } networkMap := make(map[string]*networktypes.Summary) for _, network := range networkList { networkMap[network.ID] = &network } var dockerDataList []dockerData var dockerDataListTasks []dockerData for _, service := range serviceList { dData, err := p.parseService(ctx, service, networkMap) if err != nil { logger.Errorf("Skip container %s: %v", getServiceName(dData), err) continue } if dData.ExtraConf.Docker.LBSwarm { if len(dData.NetworkSettings.Networks) > 0 { dockerDataList = append(dockerDataList, dData) } } else { isGlobalSvc := service.Spec.Mode.Global != nil dockerDataListTasks, err = listTasks(ctx, dockerClient, service.ID, dData, networkMap, isGlobalSvc) if err != nil { logger.Warn(err) } else { dockerDataList = append(dockerDataList, dockerDataListTasks...) } } } return dockerDataList, err } func (p *Provider) parseService(ctx context.Context, service swarmtypes.Service, networkMap map[string]*networktypes.Summary) (dockerData, error) { logger := log.FromContext(ctx) dData := dockerData{ ID: service.ID, ServiceName: service.Spec.Annotations.Name, Name: service.Spec.Annotations.Name, Labels: service.Spec.Annotations.Labels, NetworkSettings: networkSettings{}, } extraConf, err := p.getConfiguration(dData) if err != nil { return dockerData{}, err } dData.ExtraConf = extraConf if service.Spec.EndpointSpec != nil { if service.Spec.EndpointSpec.Mode == swarmtypes.ResolutionModeDNSRR { if dData.ExtraConf.Docker.LBSwarm { logger.Warnf("Ignored %s endpoint-mode not supported, service name: %s. Fallback to Traefik load balancing", swarmtypes.ResolutionModeDNSRR, service.Spec.Annotations.Name) } } else if service.Spec.EndpointSpec.Mode == swarmtypes.ResolutionModeVIP { dData.NetworkSettings.Networks = make(map[string]*networkData) for _, virtualIP := range service.Endpoint.VirtualIPs { networkService := networkMap[virtualIP.NetworkID] if networkService != nil { if len(virtualIP.Addr) > 0 { ip, _, _ := net.ParseCIDR(virtualIP.Addr) network := &networkData{ Name: networkService.Name, ID: virtualIP.NetworkID, Addr: ip.String(), } dData.NetworkSettings.Networks[network.Name] = network } else { logger.Debugf("No virtual IPs found in network %s", virtualIP.NetworkID) } } else { logger.Debugf("Network not found, id: %s", virtualIP.NetworkID) } } } } return dData, nil } func listTasks(ctx context.Context, dockerClient client.APIClient, serviceID string, serviceDockerData dockerData, networkMap map[string]*networktypes.Summary, isGlobalSvc bool, ) ([]dockerData, error) { serviceIDFilter := filters.NewArgs() serviceIDFilter.Add("service", serviceID) serviceIDFilter.Add("desired-state", "running") taskList, err := dockerClient.TaskList(ctx, dockertypes.TaskListOptions{Filters: serviceIDFilter}) if err != nil { return nil, err } var dockerDataList []dockerData for _, task := range taskList { if task.Status.State != swarmtypes.TaskStateRunning { continue } dData := parseTasks(ctx, task, serviceDockerData, networkMap, isGlobalSvc) if len(dData.NetworkSettings.Networks) > 0 { dockerDataList = append(dockerDataList, dData) } } return dockerDataList, err } func parseTasks(ctx context.Context, task swarmtypes.Task, serviceDockerData dockerData, networkMap map[string]*networktypes.Summary, isGlobalSvc bool, ) dockerData { dData := dockerData{ ID: task.ID, ServiceName: serviceDockerData.Name, Name: serviceDockerData.Name + "." + strconv.Itoa(task.Slot), Labels: serviceDockerData.Labels, ExtraConf: serviceDockerData.ExtraConf, NetworkSettings: networkSettings{}, } if isGlobalSvc { dData.Name = serviceDockerData.Name + "." + task.ID } if task.NetworksAttachments != nil { dData.NetworkSettings.Networks = make(map[string]*networkData) for _, virtualIP := range task.NetworksAttachments { if networkService, present := networkMap[virtualIP.Network.ID]; present { if len(virtualIP.Addresses) > 0 { // Not sure about this next loop - when would a task have multiple IP's for the same network? for _, addr := range virtualIP.Addresses { ip, _, _ := net.ParseCIDR(addr) network := &networkData{ ID: virtualIP.Network.ID, Name: networkService.Name, Addr: ip.String(), } dData.NetworkSettings.Networks[network.Name] = network } } else { log.FromContext(ctx).Debugf("No IP addresses found for network %s", virtualIP.Network.ID) } } } } return dData }