traefik/marathon.go
2015-09-21 18:05:56 +02:00

192 lines
4.8 KiB
Go

package main
import (
"bytes"
"github.com/BurntSushi/toml"
"github.com/BurntSushi/ty/fun"
"github.com/gambol99/go-marathon"
"strconv"
"strings"
"text/template"
)
type MarathonProvider struct {
Watch bool
Endpoint string
marathonClient marathon.Marathon
Domain string
Filename string
NetworkInterface string
}
func NewMarathonProvider() *MarathonProvider {
marathonProvider := new(MarathonProvider)
// default values
marathonProvider.Watch = true
marathonProvider.Domain = "traefik"
marathonProvider.NetworkInterface = "eth0"
return marathonProvider
}
var MarathonFuncMap = template.FuncMap{
"getPort": func(task marathon.Task) string {
for _, port := range task.Ports {
return strconv.Itoa(port)
}
return ""
},
"getHost": func(application marathon.Application) string {
for key, value := range application.Labels {
if key == "traefik.host" {
return value
}
}
return strings.Replace(application.ID, "/", "", 1)
},
"getWeight": func(application marathon.Application) string {
for key, value := range application.Labels {
if key == "traefik.weight" {
return value
}
}
return "0"
},
"replace": func(s1 string, s2 string, s3 string) string {
return strings.Replace(s3, s1, s2, -1)
},
}
func (provider *MarathonProvider) Provide(configurationChan chan<- *Configuration) {
config := marathon.NewDefaultConfig()
config.URL = provider.Endpoint
config.EventsInterface = provider.NetworkInterface
if client, err := marathon.NewClient(config); err != nil {
log.Error("Failed to create a client for marathon, error: %s", err)
return
} else {
provider.marathonClient = client
update := make(marathon.EventsChannel, 5)
if provider.Watch {
if err := client.AddEventsListener(update, marathon.EVENTS_APPLICATIONS); err != nil {
log.Error("Failed to register for subscriptions, %s", err)
} else {
go func() {
for {
event := <-update
log.Debug("Marathon event receveived", event)
configuration := provider.loadMarathonConfig()
if configuration != nil {
configurationChan <- configuration
}
}
}()
}
}
configuration := provider.loadMarathonConfig()
configurationChan <- configuration
}
}
func (provider *MarathonProvider) loadMarathonConfig() *Configuration {
configuration := new(Configuration)
applications, err := provider.marathonClient.Applications(nil)
if err != nil {
log.Error("Failed to create a client for marathon, error: %s", err)
return nil
}
tasks, err := provider.marathonClient.AllTasks()
if err != nil {
log.Error("Failed to create a client for marathon, error: %s", err)
return nil
}
//filter tasks
filteredTasks := fun.Filter(func(task marathon.Task) bool {
if len(task.Ports) == 0 {
log.Debug("Filtering marathon task without port", task.AppID)
return false
}
application := getApplication(task, applications.Apps)
_, err := strconv.Atoi(application.Labels["traefik.port"])
if len(application.Ports) > 1 && err != nil {
log.Debug("Filtering marathon task with more than 1 port and no traefik.port label", task.AppID)
return false
}
if application.Labels["traefik.enable"] == "false" {
log.Debug("Filtering disabled marathon task", task.AppID)
return false
}
return true
}, tasks.Tasks).([]marathon.Task)
//filter apps
filteredApps := fun.Filter(func(app marathon.Application) bool {
//get ports from app tasks
if !fun.Exists(func(task marathon.Task) bool {
if task.AppID == app.ID {
return true
}
return false
}, filteredTasks) {
return false
}
return true
}, applications.Apps).([]marathon.Application)
templateObjects := struct {
Applications []marathon.Application
Tasks []marathon.Task
Domain string
}{
filteredApps,
filteredTasks,
provider.Domain,
}
tmpl := template.New(provider.Filename).Funcs(MarathonFuncMap)
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/marathon.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 marathon template:", err)
return nil
}
if _, err := toml.Decode(buffer.String(), configuration); err != nil {
log.Error("Error creating marathon configuration:", err)
return nil
}
return configuration
}
func getApplication(task marathon.Task, apps []marathon.Application) *marathon.Application {
for _, application := range apps {
if application.ID == task.AppID {
return &application
}
}
return nil
}