Consul catalog provider

Fixes #176

cmd.go

@@ -45,6 +45,7 @@ var arguments = struct {
 	dockerTLS     bool
 	marathon      bool
 	consul        bool
+	consulCatalog bool
 	zookeeper     bool
 	etcd          bool
 	boltdb        bool
@@ -58,6 +59,7 @@ var arguments = struct {
 		Web:           &WebProvider{},
 		Marathon:      &provider.Marathon{},
 		Consul:        &provider.Consul{},
+		ConsulCatalog: &provider.ConsulCatalog{},
 		Zookeeper:     &provider.Zookepper{},
 		Etcd:          &provider.Etcd{},
 		Boltdb:        &provider.BoltDb{},
@@ -71,6 +73,7 @@ var arguments = struct {
 	false,
 	false,
 	false,
+	false,
 }
 
 func init() {
@@ -119,6 +122,10 @@ func init() {
 	traefikCmd.PersistentFlags().StringVar(&arguments.Consul.Endpoint, "consul.endpoint", "127.0.0.1:8500", "Consul server endpoint")
 	traefikCmd.PersistentFlags().StringVar(&arguments.Consul.Prefix, "consul.prefix", "/traefik", "Prefix used for KV store")
 
+	traefikCmd.PersistentFlags().BoolVar(&arguments.consulCatalog, "consulCatalog", false, "Enable Consul catalog backend")
+	traefikCmd.PersistentFlags().StringVar(&arguments.ConsulCatalog.Domain, "consulCatalog.domain", "", "Default domain used")
+	traefikCmd.PersistentFlags().StringVar(&arguments.ConsulCatalog.Endpoint, "consulCatalog.endpoint", "127.0.0.1:8500", "Consul server endpoint")
+
 	traefikCmd.PersistentFlags().BoolVar(&arguments.zookeeper, "zookeeper", false, "Enable Zookeeper backend")
 	traefikCmd.PersistentFlags().BoolVar(&arguments.Zookeeper.Watch, "zookeeper.watch", true, "Watch provider")
 	traefikCmd.PersistentFlags().StringVar(&arguments.Zookeeper.Filename, "zookeeper.filename", "", "Override default configuration template. For advanced users :)")

configuration.go

@@ -30,6 +30,7 @@ type GlobalConfiguration struct {
 	Web                       *WebProvider
 	Marathon                  *provider.Marathon
 	Consul                    *provider.Consul
+	ConsulCatalog             *provider.ConsulCatalog
 	Etcd                      *provider.Etcd
 	Zookeeper                 *provider.Zookepper
 	Boltdb                    *provider.BoltDb
@@ -224,6 +225,9 @@ func LoadConfiguration() *GlobalConfiguration {
 	if arguments.consul {
 		viper.Set("consul", arguments.Consul)
 	}
+	if arguments.consulCatalog {
+		viper.Set("consulCatalog", arguments.ConsulCatalog)
+	}
 	if arguments.zookeeper {
 		viper.Set("zookeeper", arguments.Zookeeper)
 	}

docs/index.md

@@ -12,6 +12,7 @@ ___
 - [Docker backend](#docker)
 - [Mesos/Marathon backend](#marathon)
 - [Consul backend](#consul)
+- [Consul catalog backend](#consulcatalog)
 - [Etcd backend](#etcd)
 - [Zookeeper backend](#zk)
 - [Boltdb backend](#boltdb)
@@ -109,6 +110,9 @@ Flags:
       --consul.filename string               Override default configuration template. For advanced users :)
       --consul.prefix string                 Prefix used for KV store (default "/traefik")
       --consul.watch                         Watch provider (default true)
+      --consulCatalog                        Enable Consul catalog backend
+      --consulCatalog.domain string          Default domain used
+      --consulCatalog.endpoint string        Consul server endpoint (default "127.0.0.1:8500")
       --defaultEntryPoints value             Entrypoints to be used by frontends that do not specify any entrypoint (default &main.DefaultEntryPoints(nil))
       --docker                               Enable Docker backend
       --docker.domain string                 Default domain used
@@ -842,6 +846,37 @@ The Keys-Values structure should look (using `prefix = "/traefik"`):
 | `/traefik/frontends/frontend2/routes/test_2/value` | `/test`    |
 
 
+## <a id="consulcatalog"></a> Consul catalog backend
+
+Træfɪk can be configured to use service discovery catalog of Consul as a backend configuration:
+
+```toml
+################################################################
+# Consul Catalog configuration backend
+################################################################
+
+# Enable Consul Catalog configuration backend
+#
+# Optional
+#
+[consulCatalog]
+
+# Consul server endpoint
+#
+# Required
+#
+endpoint = "127.0.0.1:8500"
+
+# Default domain used.
+#
+# Optional
+#
+domain = "consul.localhost"
+```
+
+This backend will create routes matching on hostname based on the service name
+used in consul.
+
 ## <a id="zk"></a> Zookeeper backend
 
 Træfɪk can be configured to use Zookeeper as a backend configuration:

integration/consul_catalog_test.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"os/exec"
+	"time"
+
+	"github.com/docker/docker/opts"
+	"github.com/fsouza/go-dockerclient"
+	"github.com/hashicorp/consul/api"
+	checker "github.com/vdemeester/shakers"
+	check "gopkg.in/check.v1"
+)
+
+// Consul catalog test suites
+type ConsulCatalogSuite struct {
+	BaseSuite
+	consulIP     string
+	consulClient *api.Client
+	dockerClient *docker.Client
+}
+
+func (s *ConsulCatalogSuite) GetContainer(name string) (*docker.Container, error) {
+	return s.dockerClient.InspectContainer(name)
+}
+
+func (s *ConsulCatalogSuite) SetUpSuite(c *check.C) {
+	dockerHost := os.Getenv("DOCKER_HOST")
+	if dockerHost == "" {
+		// FIXME Handle windows -- see if dockerClient already handle that or not
+		dockerHost = fmt.Sprintf("unix://%s", opts.DefaultUnixSocket)
+	}
+	// Make sure we can speak to docker
+	dockerClient, err := docker.NewClient(dockerHost)
+	c.Assert(err, checker.IsNil, check.Commentf("Error connecting to docker daemon"))
+	s.dockerClient = dockerClient
+
+	s.createComposeProject(c, "consul_catalog")
+	err = s.composeProject.Up()
+	c.Assert(err, checker.IsNil, check.Commentf("Error starting project"))
+
+	consul, err := s.GetContainer("integration-test-consul_catalog_consul_1")
+	c.Assert(err, checker.IsNil, check.Commentf("Error finding consul container"))
+
+	s.consulIP = consul.NetworkSettings.IPAddress
+	config := api.DefaultConfig()
+	config.Address = s.consulIP + ":8500"
+	consulClient, err := api.NewClient(config)
+	if err != nil {
+		c.Fatalf("Error creating consul client")
+	}
+	s.consulClient = consulClient
+
+	// Wait for consul to elect itself leader
+	time.Sleep(2000 * time.Millisecond)
+}
+
+func (s *ConsulCatalogSuite) registerService(name string, address string, port int) error {
+	catalog := s.consulClient.Catalog()
+	_, err := catalog.Register(
+		&api.CatalogRegistration{
+			Node:    address,
+			Address: address,
+			Service: &api.AgentService{
+				ID:      name,
+				Service: name,
+				Address: address,
+				Port:    port,
+			},
+		},
+		&api.WriteOptions{},
+	)
+	return err
+}
+
+func (s *ConsulCatalogSuite) deregisterService(name string, address string) error {
+	catalog := s.consulClient.Catalog()
+	_, err := catalog.Deregister(
+		&api.CatalogDeregistration{
+			Node:      address,
+			Address:   address,
+			ServiceID: name,
+		},
+		&api.WriteOptions{},
+	)
+	return err
+}
+
+func (s *ConsulCatalogSuite) TestSimpleConfiguration(c *check.C) {
+	cmd := exec.Command(traefikBinary, "--consulCatalog", "--consulCatalog.endpoint="+s.consulIP+":8500", "--configFile=fixtures/consul_catalog/simple.toml")
+	err := cmd.Start()
+	c.Assert(err, checker.IsNil)
+	defer cmd.Process.Kill()
+
+	time.Sleep(500 * time.Millisecond)
+	// TODO validate : run on 80
+	resp, err := http.Get("http://127.0.0.1:8000/")
+
+	// Expected a 404 as we did not configure anything
+	c.Assert(err, checker.IsNil)
+	c.Assert(resp.StatusCode, checker.Equals, 404)
+}
+
+func (s *ConsulCatalogSuite) TestSingleService(c *check.C) {
+	cmd := exec.Command(traefikBinary, "--consulCatalog", "--consulCatalog.endpoint="+s.consulIP+":8500", "--consulCatalog.domain=consul.localhost", "--configFile=fixtures/consul_catalog/simple.toml")
+	err := cmd.Start()
+	c.Assert(err, checker.IsNil)
+	defer cmd.Process.Kill()
+
+	nginx, err := s.GetContainer("integration-test-consul_catalog_nginx_1")
+	c.Assert(err, checker.IsNil, check.Commentf("Error finding nginx container"))
+
+	err = s.registerService("test", nginx.NetworkSettings.IPAddress, 80)
+	c.Assert(err, checker.IsNil, check.Commentf("Error registering service"))
+	defer s.deregisterService("test", nginx.NetworkSettings.IPAddress)
+
+	time.Sleep(5000 * time.Millisecond)
+	client := &http.Client{}
+	req, err := http.NewRequest("GET", "http://127.0.0.1:8000/", nil)
+	c.Assert(err, checker.IsNil)
+	req.Host = "test.consul.localhost"
+	resp, err := client.Do(req)
+
+	c.Assert(err, checker.IsNil)
+	c.Assert(resp.StatusCode, checker.Equals, 200)
+
+	_, err = ioutil.ReadAll(resp.Body)
+	c.Assert(err, checker.IsNil)
+}

integration/fixtures/consul_catalog/simple.toml

@@ -0,0 +1,9 @@
+defaultEntryPoints = ["http"]
+logLevel = "DEBUG"
+
+[entryPoints]
+  [entryPoints.http]
+  address = ":8000"
+
+[consulCatalog]
+domain = "consul.localhost"

integration/integration_test.go

@@ -28,6 +28,7 @@ func init() {
 	check.Suite(&FileSuite{})
 	check.Suite(&DockerSuite{})
 	check.Suite(&ConsulSuite{})
+	check.Suite(&ConsulCatalogSuite{})
 	check.Suite(&MarathonSuite{})
 }
 

integration/resources/compose/consul_catalog.yml

@@ -0,0 +1,17 @@
+consul:
+  image: progrium/consul
+  command: -server -bootstrap -log-level debug -ui-dir /ui
+  ports:
+    - "8400:8400"
+    - "8500:8500"
+    - "8600:53/udp"
+  expose:
+    - "8300"
+    - "8301"
+    - "8301/udp"
+    - "8302"
+    - "8302/udp"
+nginx:
+  image: nginx
+  ports:
+    - "8881:80"

provider/consul_catalog.go

@@ -0,0 +1,199 @@
+package provider
+
+import (
+	"errors"
+	"strings"
+	"text/template"
+	"time"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/cenkalti/backoff"
+	"github.com/emilevauge/traefik/types"
+	"github.com/hashicorp/consul/api"
+)
+
+const (
+	// DefaultWatchWaitTime is the duration to wait when polling consul
+	DefaultWatchWaitTime = 15 * time.Second
+)
+
+// ConsulCatalog holds configurations of the Consul catalog provider.
+type ConsulCatalog struct {
+	BaseProvider `mapstructure:",squash"`
+	Endpoint     string
+	Domain       string
+	client       *api.Client
+}
+
+type catalogUpdate struct {
+	Service string
+	Nodes   []*api.ServiceEntry
+}
+
+func (provider *ConsulCatalog) watchServices(stopCh <-chan struct{}) <-chan map[string][]string {
+	watchCh := make(chan map[string][]string)
+
+	catalog := provider.client.Catalog()
+
+	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
+	}
+
+	return catalogUpdate{
+		Service: service,
+		Nodes:   data,
+	}, nil
+}
+
+func (provider *ConsulCatalog) getBackend(node *api.ServiceEntry) string {
+	return strings.ToLower(node.Service.Service)
+}
+
+func (provider *ConsulCatalog) getFrontendValue(service string) string {
+	return service + "." + provider.Domain
+}
+
+func (provider *ConsulCatalog) buildConfig(catalog []catalogUpdate) *types.Configuration {
+	var FuncMap = template.FuncMap{
+		"getBackend":       provider.getBackend,
+		"getFrontendValue": provider.getFrontendValue,
+		"replace":          replace,
+	}
+
+	allNodes := []*api.ServiceEntry{}
+	serviceNames := []string{}
+	for _, info := range catalog {
+		if len(info.Nodes) > 0 {
+			serviceNames = append(serviceNames, info.Service)
+			allNodes = append(allNodes, info.Nodes...)
+		}
+	}
+
+	templateObjects := struct {
+		Services []string
+		Nodes    []*api.ServiceEntry
+	}{
+		Services: serviceNames,
+		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
+			}
+			nodes = append(nodes, healthy)
+		}
+	}
+	return nodes, nil
+}
+
+func (provider *ConsulCatalog) watch(configurationChan chan<- types.ConfigMessage) error {
+	stopCh := make(chan struct{})
+	serviceCatalog := provider.watchServices(stopCh)
+
+	defer close(stopCh)
+
+	for {
+		select {
+		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) error {
+	config := api.DefaultConfig()
+	config.Address = provider.Endpoint
+	client, err := api.NewClient(config)
+	if err != nil {
+		return err
+	}
+	provider.client = client
+
+	go func() {
+		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)
+		}
+		err := backoff.RetryNotify(worker, backoff.NewExponentialBackOff(), notify)
+		if err != nil {
+			log.Fatalf("Cannot connect to consul server %+v", err)
+		}
+	}()
+
+	return err
+}

provider/consul_catalog_test.go

@@ -0,0 +1,110 @@
+package provider
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/emilevauge/traefik/types"
+	"github.com/hashicorp/consul/api"
+)
+
+func TestConsulCatalogGetFrontendValue(t *testing.T) {
+	provider := &ConsulCatalog{
+		Domain: "localhost",
+	}
+
+	services := []struct {
+		service  string
+		expected string
+	}{
+		{
+			service:  "foo",
+			expected: "foo.localhost",
+		},
+	}
+
+	for _, e := range services {
+		actual := provider.getFrontendValue(e.service)
+		if actual != e.expected {
+			t.Fatalf("expected %q, got %q", e.expected, actual)
+		}
+	}
+}
+
+func TestConsulCatalogBuildConfig(t *testing.T) {
+	provider := &ConsulCatalog{
+		Domain: "localhost",
+	}
+
+	cases := []struct {
+		nodes             []catalogUpdate
+		expectedFrontends map[string]*types.Frontend
+		expectedBackends  map[string]*types.Backend
+	}{
+		{
+			nodes:             []catalogUpdate{},
+			expectedFrontends: map[string]*types.Frontend{},
+			expectedBackends:  map[string]*types.Backend{},
+		},
+		{
+			nodes: []catalogUpdate{
+				{
+					Service: "test",
+				},
+			},
+			expectedFrontends: map[string]*types.Frontend{},
+			expectedBackends:  map[string]*types.Backend{},
+		},
+		{
+			nodes: []catalogUpdate{
+				{
+					Service: "test",
+					Nodes: []*api.ServiceEntry{
+						{
+							Service: &api.AgentService{
+								Service: "test",
+								Port:    80,
+							},
+							Node: &api.Node{
+								Node:    "localhost",
+								Address: "127.0.0.1",
+							},
+						},
+					},
+				},
+			},
+			expectedFrontends: map[string]*types.Frontend{
+				"frontend-test": {
+					Backend: "backend-test",
+					Routes: map[string]types.Route{
+						"route-host-test": {
+							Rule:  "Host",
+							Value: "test.localhost",
+						},
+					},
+				},
+			},
+			expectedBackends: map[string]*types.Backend{
+				"backend-test": {
+					Servers: map[string]types.Server{
+						"server-localhost-80": {
+							URL: "http://127.0.0.1:80",
+						},
+					},
+					CircuitBreaker: nil,
+					LoadBalancer:   nil,
+				},
+			},
+		},
+	}
+
+	for _, c := range cases {
+		actualConfig := provider.buildConfig(c.nodes)
+		if !reflect.DeepEqual(actualConfig.Backends, c.expectedBackends) {
+			t.Fatalf("expected %#v, got %#v", c.expectedBackends, actualConfig.Backends)
+		}
+		if !reflect.DeepEqual(actualConfig.Frontends, c.expectedFrontends) {
+			t.Fatalf("expected %#v, got %#v", c.expectedFrontends, actualConfig.Frontends)
+		}
+	}
+}

server.go

@@ -184,6 +184,9 @@ func (server *Server) configureProviders() {
 	if server.globalConfiguration.Consul != nil {
 		server.providers = append(server.providers, server.globalConfiguration.Consul)
 	}
+	if server.globalConfiguration.ConsulCatalog != nil {
+		server.providers = append(server.providers, server.globalConfiguration.ConsulCatalog)
+	}
 	if server.globalConfiguration.Etcd != nil {
 		server.providers = append(server.providers, server.globalConfiguration.Etcd)
 	}

templates/consul_catalog.tmpl

@@ -0,0 +1,13 @@
+[backends]{{range .Nodes}}
+    [backends.backend-{{getBackend .}}.servers.server-{{.Node.Node | replace "." "-"}}-{{.Service.Port}}]
+    url = "http://{{.Node.Address}}:{{.Service.Port}}"
+{{end}}
+
+[frontends]{{range .Services}}
+  [frontends.frontend-{{.}}]
+  backend = "backend-{{.}}"
+  passHostHeader = false
+    [frontends.frontend-{{.}}.routes.route-host-{{.}}]
+    rule = "Host"
+    value = "{{getFrontendValue .}}"
+{{end}}

traefik.go

@@ -8,7 +8,6 @@ import (
 
 func main() {
 	runtime.GOMAXPROCS(runtime.NumCPU())
-
 	if err := traefikCmd.Execute(); err != nil {
 		fmtlog.Println(err)
 		os.Exit(-1)