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