Consul Backend

consul.go

@@ -0,0 +1,155 @@
+package main
+
+import (
+	"github.com/hashicorp/consul/api"
+	"text/template"
+	"bytes"
+	"github.com/BurntSushi/toml"
+	"strings"
+	"github.com/BurntSushi/ty/fun"
+	"net/http"
+)
+
+
+type Key struct {
+	Value string
+}
+
+type ConsulProvider struct {
+	Watch        bool
+	Endpoint     string
+	Prefix       string
+	Filename     string
+	consulClient *api.Client
+}
+var kvClient *api.KV
+
+var ConsulFuncMap = template.FuncMap{
+	"List": func(keys ...string) []string {
+		joinedKeys := strings.Join(keys, "")
+		keysPairs, _, err := kvClient.Keys(joinedKeys, "/", nil)
+		if err != nil {
+			log.Error("Error getting keys ", joinedKeys, err)
+			return nil
+		}
+		keysPairs = fun.Filter(func(key string) bool {
+			if (key == joinedKeys) {
+				return false
+			}
+			return true
+		}, keysPairs).([]string)
+		return keysPairs
+	},
+	"Get": func(keys ...string) string {
+		joinedKeys := strings.Join(keys, "")
+		keyPair, _, err := kvClient.Get(joinedKeys, nil)
+		if err != nil {
+			log.Error("Error getting key ", joinedKeys, err)
+			return ""
+		}
+		return string(keyPair.Value)
+	},
+	"Last": func(key string) string {
+		splittedKey := strings.Split(key, "/")
+		return splittedKey[len(splittedKey) -2]
+	},
+}
+
+func NewConsulProvider() *ConsulProvider {
+	consulProvider := new(ConsulProvider)
+	// default values
+	consulProvider.Watch = true
+	consulProvider.Prefix = "traefik"
+
+	return consulProvider
+}
+
+func (provider *ConsulProvider) Provide(configurationChan chan <- *Configuration) {
+	config := &api.Config{
+		Address:    provider.Endpoint,
+		Scheme:     "http",
+		HttpClient: http.DefaultClient,
+	}
+	consulClient, _ := api.NewClient(config)
+	provider.consulClient = consulClient
+	if provider.Watch {
+		var waitIndex uint64
+		keypairs, meta, err := consulClient.KV().Keys("", "", nil)
+		if keypairs == nil && err == nil {
+			log.Error("Key was not found.")
+		}
+		waitIndex = meta.LastIndex
+		go func() {
+			for {
+				opts := api.QueryOptions{
+					WaitIndex: waitIndex,
+				}
+				keypairs, meta, err := consulClient.KV().Keys("", "", &opts)
+				if keypairs == nil && err == nil {
+					log.Error("Key  was not found.")
+				}
+				waitIndex = meta.LastIndex
+				configuration := provider.loadConsulConfig()
+				if configuration != nil {
+					configurationChan <- configuration
+				}
+			}
+		}()
+	}
+	configuration := provider.loadConsulConfig()
+	configurationChan <- configuration
+}
+
+func (provider *ConsulProvider) loadConsulConfig() *Configuration {
+	configuration := new(Configuration)
+	services := []*api.CatalogService{}
+	kvClient = provider.consulClient.KV()
+
+	servicesName, _, _ := provider.consulClient.Catalog().Services(nil)
+	for serviceName, _ := range servicesName {
+		catalogServices, _, _ := provider.consulClient.Catalog().Service(serviceName, "", nil)
+		for _, catalogService := range catalogServices {
+			services= append(services, catalogService)
+		}
+	}
+
+	templateObjects := struct {
+		Services []*api.CatalogService
+	}{
+		services,
+	}
+
+	tmpl := template.New(provider.Filename).Funcs(ConsulFuncMap)
+	if len(provider.Filename) > 0 {
+		_, err := tmpl.ParseFiles(provider.Filename)
+		if err != nil {
+			log.Error("Error reading file", err)
+			return nil
+		}
+	} else {
+		buf, err := Asset("providerTemplates/consul.tmpl")
+		if err != nil {
+			log.Error("Error reading file", err)
+		}
+		_, err = tmpl.Parse(string(buf))
+		if err != nil {
+			log.Error("Error reading file", err)
+			return nil
+		}
+	}
+
+	var buffer bytes.Buffer
+
+	err := tmpl.Execute(&buffer, templateObjects)
+	if err != nil {
+		log.Error("Error with consul template:", err)
+		return nil
+	}
+
+	if _, err := toml.Decode(buffer.String(), configuration); err != nil {
+		log.Error("Error creating consul configuration:", err)
+		return nil
+	}
+
+	return configuration
+}