UDP support

Co-authored-by: Julien Salleyron <julien.salleyron@gmail.com>

pkg/server/service/udp/service.go

@@ -0,0 +1,81 @@
+package udp
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/containous/traefik/v2/pkg/config/runtime"
+	"github.com/containous/traefik/v2/pkg/log"
+	"github.com/containous/traefik/v2/pkg/server/provider"
+	"github.com/containous/traefik/v2/pkg/udp"
+)
+
+// Manager handles UDP services creation.
+type Manager struct {
+	configs map[string]*runtime.UDPServiceInfo
+}
+
+// NewManager creates a new manager
+func NewManager(conf *runtime.Configuration) *Manager {
+	return &Manager{
+		configs: conf.UDPServices,
+	}
+}
+
+// BuildUDP creates the UDP handler for the given service name.
+func (m *Manager) BuildUDP(rootCtx context.Context, serviceName string) (udp.Handler, error) {
+	serviceQualifiedName := provider.GetQualifiedName(rootCtx, serviceName)
+	ctx := provider.AddInContext(rootCtx, serviceQualifiedName)
+	ctx = log.With(ctx, log.Str(log.ServiceName, serviceName))
+
+	conf, ok := m.configs[serviceQualifiedName]
+	if !ok {
+		return nil, fmt.Errorf("the udp service %q does not exist", serviceQualifiedName)
+	}
+
+	if conf.LoadBalancer != nil && conf.Weighted != nil {
+		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
+	}
+
+	logger := log.FromContext(ctx)
+	switch {
+	case conf.LoadBalancer != nil:
+		loadBalancer := udp.NewWRRLoadBalancer()
+
+		for name, server := range conf.LoadBalancer.Servers {
+			if _, _, err := net.SplitHostPort(server.Address); err != nil {
+				logger.Errorf("In udp service %q: %v", serviceQualifiedName, err)
+				continue
+			}
+
+			handler, err := udp.NewProxy(server.Address)
+			if err != nil {
+				logger.Errorf("In udp service %q server %q: %v", serviceQualifiedName, server.Address, err)
+				continue
+			}
+
+			loadBalancer.AddServer(handler)
+			logger.WithField(log.ServerName, name).Debugf("Creating UDP server %d at %s", name, server.Address)
+		}
+		return loadBalancer, nil
+	case conf.Weighted != nil:
+		loadBalancer := udp.NewWRRLoadBalancer()
+		for _, service := range conf.Weighted.Services {
+			handler, err := m.BuildUDP(rootCtx, service.Name)
+			if err != nil {
+				logger.Errorf("In udp service %q: %v", serviceQualifiedName, err)
+				return nil, err
+			}
+			loadBalancer.AddWeightedServer(handler, service.Weight)
+		}
+		return loadBalancer, nil
+	default:
+		err := fmt.Errorf("the udp service %q does not have any type defined", serviceQualifiedName)
+		conf.AddError(err, true)
+		return nil, err
+	}
+}