traefik/provider/marathon/marathon.go
Timo Reimann d57f83c31c Make Traefik health checks label-configurable with Marathon.
For the two existing health check parameters (path and interval), we add
support for Marathon labels.

Changes in detail:

- Extend the Marathon provider and template.
- Refactor Server.loadConfig to reduce duplication.
- Refactor the healthcheck package slightly to accommodate the changes
  and allow extending by future parameters.
- Update documentation.
2017-04-28 18:17:25 +02:00

587 lines
19 KiB
Go

package marathon
import (
"errors"
"fmt"
"math"
"net"
"net/http"
"net/url"
"strconv"
"strings"
"text/template"
"time"
"github.com/BurntSushi/ty/fun"
"github.com/cenk/backoff"
"github.com/containous/flaeg"
"github.com/containous/traefik/job"
"github.com/containous/traefik/log"
"github.com/containous/traefik/provider"
"github.com/containous/traefik/safe"
"github.com/containous/traefik/types"
"github.com/gambol99/go-marathon"
)
const (
labelPort = "traefik.port"
labelPortIndex = "traefik.portIndex"
labelBackendHealthCheckPath = "traefik.backend.healthcheck.path"
labelBackendHealthCheckInterval = "traefik.backend.healthcheck.interval"
)
var _ provider.Provider = (*Provider)(nil)
// Provider holds configuration of the provider.
type Provider struct {
provider.BaseProvider
Endpoint string `description:"Marathon server endpoint. You can also specify multiple endpoint for Marathon"`
Domain string `description:"Default domain used"`
ExposedByDefault bool `description:"Expose Marathon apps by default"`
GroupsAsSubDomains bool `description:"Convert Marathon groups to subdomains"`
DCOSToken string `description:"DCOSToken for DCOS environment, This will override the Authorization header"`
MarathonLBCompatibility bool `description:"Add compatibility with marathon-lb labels"`
TLS *provider.ClientTLS `description:"Enable Docker TLS support"`
DialerTimeout flaeg.Duration `description:"Set a non-default connection timeout for Marathon"`
KeepAlive flaeg.Duration `description:"Set a non-default TCP Keep Alive time in seconds"`
ForceTaskHostname bool `description:"Force to use the task's hostname."`
Basic *Basic
marathonClient marathon.Marathon
}
// Basic holds basic authentication specific configurations
type Basic struct {
HTTPBasicAuthUser string
HTTPBasicPassword string
}
type lightMarathonClient interface {
AllTasks(v url.Values) (*marathon.Tasks, error)
Applications(url.Values) (*marathon.Applications, error)
}
// Provide allows the marathon provider to provide configurations to traefik
// using the given configuration channel.
func (p *Provider) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints types.Constraints) error {
p.Constraints = append(p.Constraints, constraints...)
operation := func() error {
config := marathon.NewDefaultConfig()
config.URL = p.Endpoint
config.EventsTransport = marathon.EventsTransportSSE
if p.Basic != nil {
config.HTTPBasicAuthUser = p.Basic.HTTPBasicAuthUser
config.HTTPBasicPassword = p.Basic.HTTPBasicPassword
}
if len(p.DCOSToken) > 0 {
config.DCOSToken = p.DCOSToken
}
TLSConfig, err := p.TLS.CreateTLSConfig()
if err != nil {
return err
}
config.HTTPClient = &http.Client{
Transport: &http.Transport{
DialContext: (&net.Dialer{
KeepAlive: time.Duration(p.KeepAlive),
Timeout: time.Duration(p.DialerTimeout),
}).DialContext,
TLSClientConfig: TLSConfig,
},
}
client, err := marathon.NewClient(config)
if err != nil {
log.Errorf("Failed to create a client for marathon, error: %s", err)
return err
}
p.marathonClient = client
if p.Watch {
update, err := client.AddEventsListener(marathon.EventIDApplications)
if err != nil {
log.Errorf("Failed to register for events, %s", err)
return err
}
pool.Go(func(stop chan bool) {
defer close(update)
for {
select {
case <-stop:
return
case event := <-update:
log.Debug("Provider event receveived", event)
configuration := p.loadMarathonConfig()
if configuration != nil {
configurationChan <- types.ConfigMessage{
ProviderName: "marathon",
Configuration: configuration,
}
}
}
}
})
}
configuration := p.loadMarathonConfig()
configurationChan <- types.ConfigMessage{
ProviderName: "marathon",
Configuration: configuration,
}
return nil
}
notify := func(err error, time time.Duration) {
log.Errorf("Provider connection error %+v, retrying in %s", err, time)
}
err := backoff.RetryNotify(safe.OperationWithRecover(operation), job.NewBackOff(backoff.NewExponentialBackOff()), notify)
if err != nil {
log.Errorf("Cannot connect to Provider server %+v", err)
}
return nil
}
func (p *Provider) loadMarathonConfig() *types.Configuration {
var MarathonFuncMap = template.FuncMap{
"getBackend": p.getBackend,
"getBackendServer": p.getBackendServer,
"getPort": p.getPort,
"getWeight": p.getWeight,
"getDomain": p.getDomain,
"getProtocol": p.getProtocol,
"getPassHostHeader": p.getPassHostHeader,
"getPriority": p.getPriority,
"getEntryPoints": p.getEntryPoints,
"getFrontendRule": p.getFrontendRule,
"getFrontendBackend": p.getFrontendBackend,
"hasCircuitBreakerLabels": p.hasCircuitBreakerLabels,
"hasLoadBalancerLabels": p.hasLoadBalancerLabels,
"hasMaxConnLabels": p.hasMaxConnLabels,
"getMaxConnExtractorFunc": p.getMaxConnExtractorFunc,
"getMaxConnAmount": p.getMaxConnAmount,
"getLoadBalancerMethod": p.getLoadBalancerMethod,
"getCircuitBreakerExpression": p.getCircuitBreakerExpression,
"getSticky": p.getSticky,
"hasHealthCheckLabels": p.hasHealthCheckLabels,
"getHealthCheckPath": p.getHealthCheckPath,
"getHealthCheckInterval": p.getHealthCheckInterval,
}
applications, err := p.marathonClient.Applications(nil)
if err != nil {
log.Errorf("Failed to create a client for marathon, error: %s", err)
return nil
}
tasks, err := p.marathonClient.AllTasks(&marathon.AllTasksOpts{Status: "running"})
if err != nil {
log.Errorf("Failed to create a client for marathon, error: %s", err)
return nil
}
//filter tasks
filteredTasks := fun.Filter(func(task marathon.Task) bool {
return p.taskFilter(task, applications, p.ExposedByDefault)
}, tasks.Tasks).([]marathon.Task)
//filter apps
filteredApps := fun.Filter(func(app marathon.Application) bool {
return p.applicationFilter(app, filteredTasks)
}, applications.Apps).([]marathon.Application)
templateObjects := struct {
Applications []marathon.Application
Tasks []marathon.Task
Domain string
}{
filteredApps,
filteredTasks,
p.Domain,
}
configuration, err := p.GetConfiguration("templates/marathon.tmpl", MarathonFuncMap, templateObjects)
if err != nil {
log.Error(err)
}
return configuration
}
func (p *Provider) taskFilter(task marathon.Task, applications *marathon.Applications, exposedByDefaultFlag bool) bool {
application, err := getApplication(task, applications.Apps)
if err != nil {
log.Errorf("Unable to get Marathon application %s for task %s", task.AppID, task.ID)
return false
}
if _, err = processPorts(application, task); err != nil {
log.Errorf("Filtering Marathon task %s from application %s without port: %s", task.ID, application.ID, err)
return false
}
// Filter illegal port label specification.
_, hasPortIndexLabel := p.getLabel(application, labelPortIndex)
_, hasPortLabel := p.getLabel(application, labelPort)
if hasPortIndexLabel && hasPortLabel {
log.Debugf("Filtering Marathon task %s from application %s specifying both traefik.portIndex and traefik.port labels", task.ID, application.ID)
return false
}
// Filter by constraints.
label, _ := p.getLabel(application, "traefik.tags")
constraintTags := strings.Split(label, ",")
if p.MarathonLBCompatibility {
if label, ok := p.getLabel(application, "HAPROXY_GROUP"); ok {
constraintTags = append(constraintTags, label)
}
}
if ok, failingConstraint := p.MatchConstraints(constraintTags); !ok {
if failingConstraint != nil {
log.Debugf("Filtering Marathon task %s from application %s pruned by '%v' constraint", task.ID, application.ID, failingConstraint.String())
}
return false
}
// Filter disabled application.
if !isApplicationEnabled(application, exposedByDefaultFlag) {
log.Debugf("Filtering disabled Marathon task %s from application %s", task.ID, application.ID)
return false
}
// Filter task with existing, bad health check results.
if application.HasHealthChecks() {
if task.HasHealthCheckResults() {
for _, healthcheck := range task.HealthCheckResults {
if !healthcheck.Alive {
log.Debugf("Filtering Marathon task %s from application %s with bad health check", task.ID, application.ID)
return false
}
}
}
}
return true
}
func (p *Provider) applicationFilter(app marathon.Application, filteredTasks []marathon.Task) bool {
label, _ := p.getLabel(app, "traefik.tags")
constraintTags := strings.Split(label, ",")
if p.MarathonLBCompatibility {
if label, ok := p.getLabel(app, "HAPROXY_GROUP"); ok {
constraintTags = append(constraintTags, label)
}
}
if ok, failingConstraint := p.MatchConstraints(constraintTags); !ok {
if failingConstraint != nil {
log.Debugf("Application %v pruned by '%v' constraint", app.ID, failingConstraint.String())
}
return false
}
return fun.Exists(func(task marathon.Task) bool {
return task.AppID == app.ID
}, filteredTasks)
}
func getApplication(task marathon.Task, apps []marathon.Application) (marathon.Application, error) {
for _, application := range apps {
if application.ID == task.AppID {
return application, nil
}
}
return marathon.Application{}, errors.New("Application not found: " + task.AppID)
}
func isApplicationEnabled(application marathon.Application, exposedByDefault bool) bool {
return exposedByDefault && (*application.Labels)["traefik.enable"] != "false" || (*application.Labels)["traefik.enable"] == "true"
}
func (p *Provider) getLabel(application marathon.Application, label string) (string, bool) {
for key, value := range *application.Labels {
if key == label {
return value, true
}
}
return "", false
}
func (p *Provider) getPort(task marathon.Task, applications []marathon.Application) string {
application, err := getApplication(task, applications)
if err != nil {
log.Errorf("Unable to get Marathon application %s for task %s", application.ID, task.ID)
return ""
}
port, err := processPorts(application, task)
if err != nil {
log.Errorf("Unable to process ports for Marathon application %s and task %s: %s", application.ID, task.ID, err)
return ""
}
return strconv.Itoa(port)
}
func (p *Provider) getWeight(task marathon.Task, applications []marathon.Application) string {
application, errApp := getApplication(task, applications)
if errApp != nil {
log.Errorf("Unable to get marathon application from task %s", task.AppID)
return "0"
}
if label, ok := p.getLabel(application, "traefik.weight"); ok {
return label
}
return "0"
}
func (p *Provider) getDomain(application marathon.Application) string {
if label, ok := p.getLabel(application, "traefik.domain"); ok {
return label
}
return p.Domain
}
func (p *Provider) getProtocol(task marathon.Task, applications []marathon.Application) string {
application, errApp := getApplication(task, applications)
if errApp != nil {
log.Errorf("Unable to get marathon application from task %s", task.AppID)
return "http"
}
if label, ok := p.getLabel(application, "traefik.protocol"); ok {
return label
}
return "http"
}
func (p *Provider) getSticky(application marathon.Application) string {
if sticky, ok := p.getLabel(application, "traefik.backend.loadbalancer.sticky"); ok {
return sticky
}
return "false"
}
func (p *Provider) getPassHostHeader(application marathon.Application) string {
if passHostHeader, ok := p.getLabel(application, "traefik.frontend.passHostHeader"); ok {
return passHostHeader
}
return "true"
}
func (p *Provider) getPriority(application marathon.Application) string {
if priority, ok := p.getLabel(application, "traefik.frontend.priority"); ok {
return priority
}
return "0"
}
func (p *Provider) getEntryPoints(application marathon.Application) []string {
if entryPoints, ok := p.getLabel(application, "traefik.frontend.entryPoints"); ok {
return strings.Split(entryPoints, ",")
}
return []string{}
}
// getFrontendRule returns the frontend rule for the specified application, using
// it's label. It returns a default one (Host) if the label is not present.
func (p *Provider) getFrontendRule(application marathon.Application) string {
if label, ok := p.getLabel(application, "traefik.frontend.rule"); ok {
return label
}
if p.MarathonLBCompatibility {
if label, ok := p.getLabel(application, "HAPROXY_0_VHOST"); ok {
return "Host:" + label
}
}
return "Host:" + p.getSubDomain(application.ID) + "." + p.Domain
}
func (p *Provider) getBackend(task marathon.Task, applications []marathon.Application) string {
application, errApp := getApplication(task, applications)
if errApp != nil {
log.Errorf("Unable to get marathon application from task %s", task.AppID)
return ""
}
return p.getFrontendBackend(application)
}
func (p *Provider) getFrontendBackend(application marathon.Application) string {
if label, ok := p.getLabel(application, "traefik.backend"); ok {
return label
}
return provider.Replace("/", "-", application.ID)
}
func (p *Provider) getSubDomain(name string) string {
if p.GroupsAsSubDomains {
splitedName := strings.Split(strings.TrimPrefix(name, "/"), "/")
provider.ReverseStringSlice(&splitedName)
reverseName := strings.Join(splitedName, ".")
return reverseName
}
return strings.Replace(strings.TrimPrefix(name, "/"), "/", "-", -1)
}
func (p *Provider) hasCircuitBreakerLabels(application marathon.Application) bool {
_, ok := p.getLabel(application, "traefik.backend.circuitbreaker.expression")
return ok
}
func (p *Provider) hasLoadBalancerLabels(application marathon.Application) bool {
_, errMethod := p.getLabel(application, "traefik.backend.loadbalancer.method")
_, errSticky := p.getLabel(application, "traefik.backend.loadbalancer.sticky")
return errMethod || errSticky
}
func (p *Provider) hasMaxConnLabels(application marathon.Application) bool {
if _, ok := p.getLabel(application, "traefik.backend.maxconn.amount"); !ok {
return false
}
_, ok := p.getLabel(application, "traefik.backend.maxconn.extractorfunc")
return ok
}
func (p *Provider) getMaxConnAmount(application marathon.Application) int64 {
if label, ok := p.getLabel(application, "traefik.backend.maxconn.amount"); ok {
i, errConv := strconv.ParseInt(label, 10, 64)
if errConv != nil {
log.Errorf("Unable to parse traefik.backend.maxconn.amount %s", label)
return math.MaxInt64
}
return i
}
return math.MaxInt64
}
func (p *Provider) getMaxConnExtractorFunc(application marathon.Application) string {
if label, ok := p.getLabel(application, "traefik.backend.maxconn.extractorfunc"); ok {
return label
}
return "request.host"
}
func (p *Provider) getLoadBalancerMethod(application marathon.Application) string {
if label, ok := p.getLabel(application, "traefik.backend.loadbalancer.method"); ok {
return label
}
return "wrr"
}
func (p *Provider) getCircuitBreakerExpression(application marathon.Application) string {
if label, ok := p.getLabel(application, "traefik.backend.circuitbreaker.expression"); ok {
return label
}
return "NetworkErrorRatio() > 1"
}
func (p *Provider) hasHealthCheckLabels(application marathon.Application) bool {
return p.getHealthCheckPath(application) != ""
}
func (p *Provider) getHealthCheckPath(application marathon.Application) string {
if label, ok := p.getLabel(application, labelBackendHealthCheckPath); ok {
return label
}
return ""
}
func (p *Provider) getHealthCheckInterval(application marathon.Application) string {
if label, ok := p.getLabel(application, labelBackendHealthCheckInterval); ok {
return label
}
return ""
}
func processPorts(application marathon.Application, task marathon.Task) (int, error) {
if portLabel, ok := (*application.Labels)[labelPort]; ok {
port, err := strconv.Atoi(portLabel)
switch {
case err != nil:
return 0, fmt.Errorf("failed to parse port label: %s", err)
case port <= 0:
return 0, fmt.Errorf("explicitly specified port %d must be larger than zero", port)
}
return port, nil
}
ports := retrieveAvailablePorts(application, task)
if len(ports) == 0 {
return 0, errors.New("no port found")
}
portIndex := 0
portIndexLabel, ok := (*application.Labels)[labelPortIndex]
if ok {
var err error
portIndex, err = parseIndex(portIndexLabel, len(ports))
if err != nil {
return 0, fmt.Errorf("cannot use port index to select from %d ports: %s", len(ports), err)
}
}
return ports[portIndex], nil
}
func retrieveAvailablePorts(application marathon.Application, task marathon.Task) []int {
// Using default port configuration
if task.Ports != nil && len(task.Ports) > 0 {
return task.Ports
}
// Using port definition if available
if application.PortDefinitions != nil && len(*application.PortDefinitions) > 0 {
var ports []int
for _, def := range *application.PortDefinitions {
if def.Port != nil {
ports = append(ports, *def.Port)
}
}
return ports
}
// If using IP-per-task using this port definition
if application.IPAddressPerTask != nil && len(*((*application.IPAddressPerTask).Discovery).Ports) > 0 {
var ports []int
for _, def := range *((*application.IPAddressPerTask).Discovery).Ports {
ports = append(ports, def.Number)
}
return ports
}
return []int{}
}
func (p *Provider) getBackendServer(task marathon.Task, applications []marathon.Application) string {
application, err := getApplication(task, applications)
if err != nil {
log.Errorf("Unable to get marathon application from task %s", task.AppID)
return ""
}
numTaskIPAddresses := len(task.IPAddresses)
switch {
case application.IPAddressPerTask == nil || p.ForceTaskHostname:
return task.Host
case numTaskIPAddresses == 0:
log.Errorf("Missing IP address for Marathon application %s on task %s", application.ID, task.ID)
return ""
case numTaskIPAddresses == 1:
return task.IPAddresses[0].IPAddress
default:
ipAddressIdxStr, ok := p.getLabel(application, "traefik.ipAddressIdx")
if !ok {
log.Errorf("Found %d task IP addresses but missing IP address index for Marathon application %s on task %s", numTaskIPAddresses, application.ID, task.ID)
return ""
}
ipAddressIdx, err := parseIndex(ipAddressIdxStr, numTaskIPAddresses)
if err != nil {
log.Errorf("Cannot use IP address index to select from %d task IP addresses for Marathon application %s on task %s: %s", numTaskIPAddresses, application.ID, task.ID, err)
return ""
}
return task.IPAddresses[ipAddressIdx].IPAddress
}
}
func parseIndex(index string, length int) (int, error) {
parsed, err := strconv.Atoi(index)
switch {
case err != nil:
return 0, fmt.Errorf("failed to parse index '%s': %s", index, err)
case parsed < 0, parsed > length-1:
return 0, fmt.Errorf("index %d must be within range (0, %d)", parsed, length-1)
}
return parsed, nil
}