traefik/pkg/server/service/service.go
Tom Moulard 79aab5aab8
Add Failover service
Co-authored-by: Kevin Pollet <pollet.kevin@gmail.com>
2022-03-17 12:02:09 +01:00

439 lines
13 KiB
Go

package service
import (
"context"
"errors"
"fmt"
"net/http"
"net/http/httputil"
"net/url"
"reflect"
"time"
"github.com/containous/alice"
"github.com/traefik/traefik/v2/pkg/config/dynamic"
"github.com/traefik/traefik/v2/pkg/config/runtime"
"github.com/traefik/traefik/v2/pkg/healthcheck"
"github.com/traefik/traefik/v2/pkg/log"
"github.com/traefik/traefik/v2/pkg/metrics"
"github.com/traefik/traefik/v2/pkg/middlewares/accesslog"
"github.com/traefik/traefik/v2/pkg/middlewares/emptybackendhandler"
metricsMiddle "github.com/traefik/traefik/v2/pkg/middlewares/metrics"
"github.com/traefik/traefik/v2/pkg/middlewares/pipelining"
"github.com/traefik/traefik/v2/pkg/safe"
"github.com/traefik/traefik/v2/pkg/server/cookie"
"github.com/traefik/traefik/v2/pkg/server/provider"
"github.com/traefik/traefik/v2/pkg/server/service/loadbalancer/failover"
"github.com/traefik/traefik/v2/pkg/server/service/loadbalancer/mirror"
"github.com/traefik/traefik/v2/pkg/server/service/loadbalancer/wrr"
"github.com/vulcand/oxy/roundrobin"
"github.com/vulcand/oxy/roundrobin/stickycookie"
)
const (
defaultHealthCheckInterval = 30 * time.Second
defaultHealthCheckTimeout = 5 * time.Second
)
const defaultMaxBodySize int64 = -1
// RoundTripperGetter is a roundtripper getter interface.
type RoundTripperGetter interface {
Get(name string) (http.RoundTripper, error)
}
// NewManager creates a new Manager.
func NewManager(configs map[string]*runtime.ServiceInfo, metricsRegistry metrics.Registry, routinePool *safe.Pool, roundTripperManager RoundTripperGetter) *Manager {
return &Manager{
routinePool: routinePool,
metricsRegistry: metricsRegistry,
bufferPool: newBufferPool(),
roundTripperManager: roundTripperManager,
balancers: make(map[string]healthcheck.Balancers),
configs: configs,
}
}
// Manager The service manager.
type Manager struct {
routinePool *safe.Pool
metricsRegistry metrics.Registry
bufferPool httputil.BufferPool
roundTripperManager RoundTripperGetter
// balancers is the map of all Balancers, keyed by service name.
// There is one Balancer per service handler, and there is one service handler per reference to a service
// (e.g. if 2 routers refer to the same service name, 2 service handlers are created),
// which is why there is not just one Balancer per service name.
balancers map[string]healthcheck.Balancers
configs map[string]*runtime.ServiceInfo
}
// BuildHTTP Creates a http.Handler for a service configuration.
func (m *Manager) BuildHTTP(rootCtx context.Context, serviceName string) (http.Handler, error) {
ctx := log.With(rootCtx, log.Str(log.ServiceName, serviceName))
serviceName = provider.GetQualifiedName(ctx, serviceName)
ctx = provider.AddInContext(ctx, serviceName)
conf, ok := m.configs[serviceName]
if !ok {
return nil, fmt.Errorf("the service %q does not exist", serviceName)
}
value := reflect.ValueOf(*conf.Service)
var count int
for i := 0; i < value.NumField(); i++ {
if !value.Field(i).IsNil() {
count++
}
}
if count > 1 {
err := errors.New("cannot create service: multi-types service not supported, consider declaring two different pieces of service instead")
conf.AddError(err, true)
return nil, err
}
var lb http.Handler
switch {
case conf.LoadBalancer != nil:
var err error
lb, err = m.getLoadBalancerServiceHandler(ctx, serviceName, conf.LoadBalancer)
if err != nil {
conf.AddError(err, true)
return nil, err
}
case conf.Weighted != nil:
var err error
lb, err = m.getWRRServiceHandler(ctx, serviceName, conf.Weighted)
if err != nil {
conf.AddError(err, true)
return nil, err
}
case conf.Mirroring != nil:
var err error
lb, err = m.getMirrorServiceHandler(ctx, conf.Mirroring)
if err != nil {
conf.AddError(err, true)
return nil, err
}
case conf.Failover != nil:
var err error
lb, err = m.getFailoverServiceHandler(ctx, serviceName, conf.Failover)
if err != nil {
conf.AddError(err, true)
return nil, err
}
default:
sErr := fmt.Errorf("the service %q does not have any type defined", serviceName)
conf.AddError(sErr, true)
return nil, sErr
}
return lb, nil
}
func (m *Manager) getFailoverServiceHandler(ctx context.Context, serviceName string, config *dynamic.Failover) (http.Handler, error) {
f := failover.New(config.HealthCheck)
serviceHandler, err := m.BuildHTTP(ctx, config.Service)
if err != nil {
return nil, err
}
f.SetHandler(serviceHandler)
updater, ok := serviceHandler.(healthcheck.StatusUpdater)
if !ok {
return nil, fmt.Errorf("child service %v of %v not a healthcheck.StatusUpdater (%T)", config.Service, serviceName, serviceHandler)
}
if err := updater.RegisterStatusUpdater(func(up bool) {
f.SetHandlerStatus(ctx, up)
}); err != nil {
return nil, fmt.Errorf("cannot register %v as updater for %v: %w", config.Service, serviceName, err)
}
fallbackHandler, err := m.BuildHTTP(ctx, config.Fallback)
if err != nil {
return nil, err
}
f.SetFallbackHandler(fallbackHandler)
// Do not report the health of the fallback handler.
if config.HealthCheck == nil {
return f, nil
}
fallbackUpdater, ok := fallbackHandler.(healthcheck.StatusUpdater)
if !ok {
return nil, fmt.Errorf("child service %v of %v not a healthcheck.StatusUpdater (%T)", config.Fallback, serviceName, fallbackHandler)
}
if err := fallbackUpdater.RegisterStatusUpdater(func(up bool) {
f.SetFallbackHandlerStatus(ctx, up)
}); err != nil {
return nil, fmt.Errorf("cannot register %v as updater for %v: %w", config.Fallback, serviceName, err)
}
return f, nil
}
func (m *Manager) getMirrorServiceHandler(ctx context.Context, config *dynamic.Mirroring) (http.Handler, error) {
serviceHandler, err := m.BuildHTTP(ctx, config.Service)
if err != nil {
return nil, err
}
maxBodySize := defaultMaxBodySize
if config.MaxBodySize != nil {
maxBodySize = *config.MaxBodySize
}
handler := mirror.New(serviceHandler, m.routinePool, maxBodySize, config.HealthCheck)
for _, mirrorConfig := range config.Mirrors {
mirrorHandler, err := m.BuildHTTP(ctx, mirrorConfig.Name)
if err != nil {
return nil, err
}
err = handler.AddMirror(mirrorHandler, mirrorConfig.Percent)
if err != nil {
return nil, err
}
}
return handler, nil
}
func (m *Manager) getWRRServiceHandler(ctx context.Context, serviceName string, config *dynamic.WeightedRoundRobin) (http.Handler, error) {
// TODO Handle accesslog and metrics with multiple service name
if config.Sticky != nil && config.Sticky.Cookie != nil {
config.Sticky.Cookie.Name = cookie.GetName(config.Sticky.Cookie.Name, serviceName)
}
balancer := wrr.New(config.Sticky, config.HealthCheck)
for _, service := range config.Services {
serviceHandler, err := m.BuildHTTP(ctx, service.Name)
if err != nil {
return nil, err
}
balancer.AddService(service.Name, serviceHandler, service.Weight)
if config.HealthCheck == nil {
continue
}
childName := service.Name
updater, ok := serviceHandler.(healthcheck.StatusUpdater)
if !ok {
return nil, fmt.Errorf("child service %v of %v not a healthcheck.StatusUpdater (%T)", childName, serviceName, serviceHandler)
}
if err := updater.RegisterStatusUpdater(func(up bool) {
balancer.SetStatus(ctx, childName, up)
}); err != nil {
return nil, fmt.Errorf("cannot register %v as updater for %v: %w", childName, serviceName, err)
}
log.FromContext(ctx).Debugf("Child service %v will update parent %v on status change", childName, serviceName)
}
return balancer, nil
}
func (m *Manager) getLoadBalancerServiceHandler(ctx context.Context, serviceName string, service *dynamic.ServersLoadBalancer) (http.Handler, error) {
if service.PassHostHeader == nil {
defaultPassHostHeader := true
service.PassHostHeader = &defaultPassHostHeader
}
if len(service.ServersTransport) > 0 {
service.ServersTransport = provider.GetQualifiedName(ctx, service.ServersTransport)
}
roundTripper, err := m.roundTripperManager.Get(service.ServersTransport)
if err != nil {
return nil, err
}
fwd, err := buildProxy(service.PassHostHeader, service.ResponseForwarding, roundTripper, m.bufferPool)
if err != nil {
return nil, err
}
alHandler := func(next http.Handler) (http.Handler, error) {
return accesslog.NewFieldHandler(next, accesslog.ServiceName, serviceName, accesslog.AddServiceFields), nil
}
chain := alice.New()
if m.metricsRegistry != nil && m.metricsRegistry.IsSvcEnabled() {
chain = chain.Append(metricsMiddle.WrapServiceHandler(ctx, m.metricsRegistry, serviceName))
}
handler, err := chain.Append(alHandler).Then(pipelining.New(ctx, fwd, "pipelining"))
if err != nil {
return nil, err
}
balancer, err := m.getLoadBalancer(ctx, serviceName, service, handler)
if err != nil {
return nil, err
}
// TODO rename and checks
m.balancers[serviceName] = append(m.balancers[serviceName], balancer)
// Empty (backend with no servers)
return emptybackendhandler.New(balancer), nil
}
// LaunchHealthCheck launches the health checks.
func (m *Manager) LaunchHealthCheck() {
backendConfigs := make(map[string]*healthcheck.BackendConfig)
for serviceName, balancers := range m.balancers {
ctx := log.With(context.Background(), log.Str(log.ServiceName, serviceName))
service := m.configs[serviceName].LoadBalancer
// Health Check
hcOpts := buildHealthCheckOptions(ctx, balancers, serviceName, service.HealthCheck)
if hcOpts == nil {
continue
}
hcOpts.Transport, _ = m.roundTripperManager.Get(service.ServersTransport)
log.FromContext(ctx).Debugf("Setting up healthcheck for service %s with %s", serviceName, *hcOpts)
backendConfigs[serviceName] = healthcheck.NewBackendConfig(*hcOpts, serviceName)
}
healthcheck.GetHealthCheck(m.metricsRegistry).SetBackendsConfiguration(context.Background(), backendConfigs)
}
func buildHealthCheckOptions(ctx context.Context, lb healthcheck.Balancer, backend string, hc *dynamic.ServerHealthCheck) *healthcheck.Options {
if hc == nil || hc.Path == "" {
return nil
}
logger := log.FromContext(ctx)
interval := defaultHealthCheckInterval
if hc.Interval != "" {
intervalOverride, err := time.ParseDuration(hc.Interval)
switch {
case err != nil:
logger.Errorf("Illegal health check interval for '%s': %s", backend, err)
case intervalOverride <= 0:
logger.Errorf("Health check interval smaller than zero for service '%s'", backend)
default:
interval = intervalOverride
}
}
timeout := defaultHealthCheckTimeout
if hc.Timeout != "" {
timeoutOverride, err := time.ParseDuration(hc.Timeout)
switch {
case err != nil:
logger.Errorf("Illegal health check timeout for backend '%s': %s", backend, err)
case timeoutOverride <= 0:
logger.Errorf("Health check timeout smaller than zero for backend '%s', backend", backend)
default:
timeout = timeoutOverride
}
}
if timeout >= interval {
logger.Warnf("Health check timeout for backend '%s' should be lower than the health check interval. Interval set to timeout + 1 second (%s).", backend, interval)
}
followRedirects := true
if hc.FollowRedirects != nil {
followRedirects = *hc.FollowRedirects
}
return &healthcheck.Options{
Scheme: hc.Scheme,
Path: hc.Path,
Port: hc.Port,
Interval: interval,
Timeout: timeout,
LB: lb,
Hostname: hc.Hostname,
Headers: hc.Headers,
FollowRedirects: followRedirects,
}
}
func (m *Manager) getLoadBalancer(ctx context.Context, serviceName string, service *dynamic.ServersLoadBalancer, fwd http.Handler) (healthcheck.BalancerStatusHandler, error) {
logger := log.FromContext(ctx)
logger.Debug("Creating load-balancer")
var options []roundrobin.LBOption
var cookieName string
if service.Sticky != nil && service.Sticky.Cookie != nil {
cookieName = cookie.GetName(service.Sticky.Cookie.Name, serviceName)
opts := roundrobin.CookieOptions{
HTTPOnly: service.Sticky.Cookie.HTTPOnly,
Secure: service.Sticky.Cookie.Secure,
SameSite: convertSameSite(service.Sticky.Cookie.SameSite),
}
// Sticky Cookie Value
cv, err := stickycookie.NewFallbackValue(&stickycookie.RawValue{}, &stickycookie.HashValue{})
if err != nil {
return nil, err
}
options = append(options, roundrobin.EnableStickySession(roundrobin.NewStickySessionWithOptions(cookieName, opts).SetCookieValue(cv)))
logger.Debugf("Sticky session cookie name: %v", cookieName)
}
lb, err := roundrobin.New(fwd, options...)
if err != nil {
return nil, err
}
lbsu := healthcheck.NewLBStatusUpdater(lb, m.configs[serviceName], service.HealthCheck)
if err := m.upsertServers(ctx, lbsu, service.Servers); err != nil {
return nil, fmt.Errorf("error configuring load balancer for service %s: %w", serviceName, err)
}
return lbsu, nil
}
func (m *Manager) upsertServers(ctx context.Context, lb healthcheck.BalancerHandler, servers []dynamic.Server) error {
logger := log.FromContext(ctx)
for name, srv := range servers {
u, err := url.Parse(srv.URL)
if err != nil {
return fmt.Errorf("error parsing server URL %s: %w", srv.URL, err)
}
logger.WithField(log.ServerName, name).Debugf("Creating server %d %s", name, u)
if err := lb.UpsertServer(u, roundrobin.Weight(1)); err != nil {
return fmt.Errorf("error adding server %s to load balancer: %w", srv.URL, err)
}
// FIXME Handle Metrics
}
return nil
}
func convertSameSite(sameSite string) http.SameSite {
switch sameSite {
case "none":
return http.SameSiteNoneMode
case "lax":
return http.SameSiteLaxMode
case "strict":
return http.SameSiteStrictMode
default:
return 0
}
}