package provider import ( "errors" "strconv" "strings" "text/template" "time" log "github.com/Sirupsen/logrus" "github.com/cenkalti/backoff" "github.com/containous/traefik/safe" "github.com/containous/traefik/types" "github.com/hashicorp/consul/api" ) const ( // DefaultWatchWaitTime is the duration to wait when polling consul DefaultWatchWaitTime = 15 * time.Second // DefaultConsulCatalogTagPrefix is a prefix for additional service/node configurations DefaultConsulCatalogTagPrefix = "traefik" ) // ConsulCatalog holds configurations of the Consul catalog provider. type ConsulCatalog struct { BaseProvider Endpoint string `description:"Consul server endpoint"` Domain string `description:"Default domain used"` client *api.Client Prefix string } type serviceUpdate struct { ServiceName string Attributes []string } type catalogUpdate struct { Service *serviceUpdate Nodes []*api.ServiceEntry } func (provider *ConsulCatalog) watchServices(stopCh <-chan struct{}) <-chan map[string][]string { watchCh := make(chan map[string][]string) catalog := provider.client.Catalog() safe.Go(func() { defer close(watchCh) opts := &api.QueryOptions{WaitTime: DefaultWatchWaitTime} for { select { case <-stopCh: return default: } data, meta, err := catalog.Services(opts) if err != nil { log.WithError(err).Errorf("Failed to list services") return } // If LastIndex didn't change then it means `Get` returned // because of the WaitTime and the key didn't changed. if opts.WaitIndex == meta.LastIndex { continue } opts.WaitIndex = meta.LastIndex if data != nil { watchCh <- data } } }) return watchCh } func (provider *ConsulCatalog) healthyNodes(service string) (catalogUpdate, error) { health := provider.client.Health() opts := &api.QueryOptions{} data, _, err := health.Service(service, "", true, opts) if err != nil { log.WithError(err).Errorf("Failed to fetch details of " + service) return catalogUpdate{}, err } set := map[string]bool{} tags := []string{} nodes := []*api.ServiceEntry{} for _, node := range data { constraintTags := provider.getContraintTags(node.Service.Tags) if ok, failingConstraint, err := provider.MatchConstraints(constraintTags); err != nil { return catalogUpdate{}, err } else if ok == true { nodes = append(nodes, node) // merge tags of every nodes in a single slice // only if node match constraint for _, tag := range node.Service.Tags { if _, ok := set[tag]; ok == false { set[tag] = true tags = append(tags, tag) } } } else if ok == false && failingConstraint != nil { log.Debugf("Service %v pruned by '%v' constraint", service, failingConstraint.String()) } } return catalogUpdate{ Service: &serviceUpdate{ ServiceName: service, Attributes: tags, }, Nodes: nodes, }, nil } func (provider *ConsulCatalog) getEntryPoints(list string) []string { return strings.Split(list, ",") } func (provider *ConsulCatalog) getBackend(node *api.ServiceEntry) string { return strings.ToLower(node.Service.Service) } func (provider *ConsulCatalog) getFrontendRule(service serviceUpdate) string { customFrontendRule := provider.getAttribute("frontend.rule", service.Attributes, "") if customFrontendRule != "" { return customFrontendRule } return "Host:" + service.ServiceName + "." + provider.Domain } func (provider *ConsulCatalog) getBackendAddress(node *api.ServiceEntry) string { if node.Service.Address != "" { return node.Service.Address } return node.Node.Address } func (provider *ConsulCatalog) getBackendName(node *api.ServiceEntry, index int) string { serviceName := node.Service.Service + "--" + node.Service.Address + "--" + strconv.Itoa(node.Service.Port) for _, tag := range node.Service.Tags { serviceName += "--" + normalize(tag) } serviceName = strings.Replace(serviceName, ".", "-", -1) serviceName = strings.Replace(serviceName, "=", "-", -1) // unique int at the end serviceName += "--" + strconv.Itoa(index) return serviceName } func (provider *ConsulCatalog) getAttribute(name string, tags []string, defaultValue string) string { for _, tag := range tags { if strings.Index(strings.ToLower(tag), DefaultConsulCatalogTagPrefix+".") == 0 { if kv := strings.SplitN(tag[len(DefaultConsulCatalogTagPrefix+"."):], "=", 2); len(kv) == 2 && strings.ToLower(kv[0]) == strings.ToLower(name) { return kv[1] } } } return defaultValue } func (provider *ConsulCatalog) getContraintTags(tags []string) []string { var list []string for _, tag := range tags { if strings.Index(strings.ToLower(tag), DefaultConsulCatalogTagPrefix+".tags=") == 0 { splitedTags := strings.Split(tag[len(DefaultConsulCatalogTagPrefix+".tags="):], ",") list = append(list, splitedTags...) } } return list } func (provider *ConsulCatalog) buildConfig(catalog []catalogUpdate) *types.Configuration { var FuncMap = template.FuncMap{ "getBackend": provider.getBackend, "getFrontendRule": provider.getFrontendRule, "getBackendName": provider.getBackendName, "getBackendAddress": provider.getBackendAddress, "getAttribute": provider.getAttribute, "getEntryPoints": provider.getEntryPoints, } allNodes := []*api.ServiceEntry{} services := []*serviceUpdate{} for _, info := range catalog { for _, node := range info.Nodes { isEnabled := provider.getAttribute("enable", node.Service.Tags, "true") if isEnabled != "false" && len(info.Nodes) > 0 { services = append(services, info.Service) allNodes = append(allNodes, info.Nodes...) break } } } templateObjects := struct { Services []*serviceUpdate Nodes []*api.ServiceEntry }{ Services: services, Nodes: allNodes, } configuration, err := provider.getConfiguration("templates/consul_catalog.tmpl", FuncMap, templateObjects) if err != nil { log.WithError(err).Error("Failed to create config") } return configuration } func (provider *ConsulCatalog) getNodes(index map[string][]string) ([]catalogUpdate, error) { visited := make(map[string]bool) nodes := []catalogUpdate{} for service := range index { name := strings.ToLower(service) if !strings.Contains(name, " ") && !visited[name] { visited[name] = true log.WithFields(log.Fields{ "service": name, }).Debug("Fetching service") healthy, err := provider.healthyNodes(name) if err != nil { return nil, err } // healthy.Nodes can be empty if constraints do not match, without throwing error if healthy.Service != nil && len(healthy.Nodes) > 0 { nodes = append(nodes, healthy) } } } return nodes, nil } func (provider *ConsulCatalog) watch(configurationChan chan<- types.ConfigMessage, stop chan bool) error { stopCh := make(chan struct{}) serviceCatalog := provider.watchServices(stopCh) defer close(stopCh) for { select { case <-stop: return nil case index, ok := <-serviceCatalog: if !ok { return errors.New("Consul service list nil") } log.Debug("List of services changed") nodes, err := provider.getNodes(index) if err != nil { return err } configuration := provider.buildConfig(nodes) configurationChan <- types.ConfigMessage{ ProviderName: "consul_catalog", Configuration: configuration, } } } } // Provide allows the provider to provide configurations to traefik // using the given configuration channel. func (provider *ConsulCatalog) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints []*types.Constraint) error { config := api.DefaultConfig() config.Address = provider.Endpoint client, err := api.NewClient(config) if err != nil { return err } provider.client = client provider.Constraints = append(provider.Constraints, constraints...) pool.Go(func(stop chan bool) { notify := func(err error, time time.Duration) { log.Errorf("Consul connection error %+v, retrying in %s", err, time) } worker := func() error { return provider.watch(configurationChan, stop) } err := backoff.RetryNotify(worker, backoff.NewExponentialBackOff(), notify) if err != nil { log.Fatalf("Cannot connect to consul server %+v", err) } }) return err }