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

194 lines
5.2 KiB
Go

package main
import (
"bytes"
"errors"
"github.com/BurntSushi/toml"
"github.com/BurntSushi/ty/fun"
"github.com/cenkalti/backoff"
"github.com/fsouza/go-dockerclient"
"strconv"
"strings"
"text/template"
"time"
)
type DockerProvider struct {
Watch bool
Endpoint string
Filename string
Domain string
}
func NewDockerProvider() *DockerProvider {
dockerProvider := new(DockerProvider)
// default
dockerProvider.Watch = true
dockerProvider.Domain = "traefik"
return dockerProvider
}
var DockerFuncMap = template.FuncMap{
"getBackend": func(container docker.Container) string {
for key, value := range container.Config.Labels {
if key == "traefik.backend" {
return value
}
}
return getHost(container)
},
"getPort": func(container docker.Container) string {
for key, value := range container.Config.Labels {
if key == "traefik.port" {
return value
}
}
for key := range container.NetworkSettings.Ports {
return key.Port()
}
return ""
},
"getWeight": func(container docker.Container) string {
for key, value := range container.Config.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)
},
"getHost": getHost,
}
func (provider *DockerProvider) Provide(configurationChan chan<- *Configuration) {
if dockerClient, err := docker.NewClient(provider.Endpoint); err != nil {
log.Fatalf("Failed to create a client for docker, error: %s", err)
} else {
err := dockerClient.Ping()
if err != nil {
log.Fatalf("Docker connection error %+v", err)
}
log.Debug("Docker connection established")
if provider.Watch {
dockerEvents := make(chan *docker.APIEvents)
dockerClient.AddEventListener(dockerEvents)
log.Debug("Docker listening")
go func() {
operation := func() error {
for {
event := <-dockerEvents
if event == nil {
return errors.New("Docker event nil")
// log.Fatalf("Docker connection error")
}
if event.Status == "start" || event.Status == "die" {
log.Debug("Docker event receveived %+v", event)
configuration := provider.loadDockerConfig(dockerClient)
if configuration != nil {
configurationChan <- configuration
}
}
}
}
notify := func(err error, time time.Duration) {
log.Error("Docker connection error %+v, retrying in %s", err, time)
}
err := backoff.RetryNotify(operation, backoff.NewExponentialBackOff(), notify)
if err != nil {
log.Fatalf("Cannot connect to docker server %+v", err)
}
}()
}
configuration := provider.loadDockerConfig(dockerClient)
configurationChan <- configuration
}
}
func (provider *DockerProvider) loadDockerConfig(dockerClient *docker.Client) *Configuration {
configuration := new(Configuration)
containerList, _ := dockerClient.ListContainers(docker.ListContainersOptions{})
containersInspected := []docker.Container{}
hosts := map[string][]docker.Container{}
// get inspect containers
for _, container := range containerList {
containerInspected, _ := dockerClient.InspectContainer(container.ID)
containersInspected = append(containersInspected, *containerInspected)
}
// filter containers
filteredContainers := fun.Filter(func(container docker.Container) bool {
if len(container.NetworkSettings.Ports) == 0 {
log.Debug("Filtering container without port %s", container.Name)
return false
}
_, err := strconv.Atoi(container.Config.Labels["traefik.port"])
if len(container.NetworkSettings.Ports) > 1 && err != nil {
log.Debug("Filtering container with more than 1 port and no traefik.port label %s", container.Name)
return false
}
if container.Config.Labels["traefik.enable"] == "false" {
log.Debug("Filtering disabled container %s", container.Name)
return false
}
return true
}, containersInspected).([]docker.Container)
for _, container := range filteredContainers {
hosts[getHost(container)] = append(hosts[getHost(container)], container)
}
templateObjects := struct {
Containers []docker.Container
Hosts map[string][]docker.Container
Domain string
}{
filteredContainers,
hosts,
provider.Domain,
}
tmpl := template.New(provider.Filename).Funcs(DockerFuncMap)
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/docker.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 docker template", err)
return nil
}
if _, err := toml.Decode(buffer.String(), configuration); err != nil {
log.Error("Error creating docker configuration", err)
return nil
}
return configuration
}
func getHost(container docker.Container) string {
for key, value := range container.Config.Labels {
if key == "traefik.host" {
return value
}
}
return strings.Replace(strings.Replace(container.Name, "/", "", -1), ".", "-", -1)
}