Add option to set Gateway status address

Co-authored-by: Romain <rtribotte@users.noreply.github.com>

docs/content/providers/kubernetes-gateway.md

@@ -212,6 +212,85 @@ providers:
 --providers.kubernetesgateway.namespaces=default,production
 ```
 
+### `statusAddress`
+
+#### `ip`
+
+_Optional, Default: ""_
+
+This IP will get copied to the Gateway `status.addresses`, and currently only supports one IP value (IPv4 or IPv6).
+
+```yaml tab="File (YAML)"
+providers:
+  kubernetesGateway:
+    statusAddress:
+      ip: "1.2.3.4"
+    # ...
+```
+
+```toml tab="File (TOML)"
+[providers.kubernetesGateway.statusAddress]
+  ip = "1.2.3.4"
+  # ...
+```
+
+```bash tab="CLI"
+--providers.kubernetesgateway.statusaddress.ip=1.2.3.4
+```
+
+#### `hostname`
+
+_Optional, Default: ""_
+
+This Hostname will get copied to the Gateway `status.addresses`.
+
+```yaml tab="File (YAML)"
+providers:
+  kubernetesGateway:
+    statusAddress:
+      hostname: "example.net"
+    # ...
+```
+
+```toml tab="File (TOML)"
+[providers.kubernetesGateway.statusAddress]
+  hostname = "example.net"
+  # ...
+```
+
+```bash tab="CLI"
+--providers.kubernetesgateway.statusaddress.hostname=example.net
+```
+
+#### `service`
+
+_Optional_
+
+The Kubernetes service to copy status addresses from.
+When using third parties tools like External-DNS, this option can be used to copy the service `loadbalancer.status` (containing the service's endpoints IPs) to the gateways.
+
+```yaml tab="File (YAML)"
+providers:
+  kubernetesGateway:
+    statusAddress:
+      service:
+        namespace: default
+        name: foo
+    # ...
+```
+
+```toml tab="File (TOML)"
+[providers.kubernetesGateway.statusAddress.service]
+  namespace = "default"
+  name = "foo"
+  # ...
+```
+
+```bash tab="CLI"
+--providers.kubernetesgateway.statusaddress.service.namespace=default
+--providers.kubernetesgateway.statusaddress.service.name=foo
+```
+
 ### `experimentalChannel`
 
 _Optional, Default: false_

docs/content/reference/static-configuration/cli-ref.md

@@ -738,6 +738,21 @@ Kubernetes label selector to select specific GatewayClasses.
 `--providers.kubernetesgateway.namespaces`:  
 Kubernetes namespaces.
 
+`--providers.kubernetesgateway.statusaddress.hostname`:  
+Hostname used for Kubernetes Gateway status address.
+
+`--providers.kubernetesgateway.statusaddress.ip`:  
+IP used to set Kubernetes Gateway status address.
+
+`--providers.kubernetesgateway.statusaddress.service`:  
+Published Kubernetes Service to copy status addresses from.
+
+`--providers.kubernetesgateway.statusaddress.service.name`:  
+Name of the Kubernetes service.
+
+`--providers.kubernetesgateway.statusaddress.service.namespace`:  
+Namespace of the Kubernetes service.
+
 `--providers.kubernetesgateway.throttleduration`:  
 Kubernetes refresh throttle duration (Default: ```0```)
 

docs/content/reference/static-configuration/env-ref.md

@@ -738,6 +738,21 @@ Kubernetes label selector to select specific GatewayClasses.
 `TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_NAMESPACES`:  
 Kubernetes namespaces.
 
+`TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_STATUSADDRESS_HOSTNAME`:  
+Hostname used for Kubernetes Gateway status address.
+
+`TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_STATUSADDRESS_IP`:  
+IP used to set Kubernetes Gateway status address.
+
+`TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_STATUSADDRESS_SERVICE`:  
+Published Kubernetes Service to copy status addresses from.
+
+`TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_STATUSADDRESS_SERVICE_NAME`:  
+Name of the Kubernetes service.
+
+`TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_STATUSADDRESS_SERVICE_NAMESPACE`:  
+Namespace of the Kubernetes service.
+
 `TRAEFIK_PROVIDERS_KUBERNETESGATEWAY_THROTTLEDURATION`:  
 Kubernetes refresh throttle duration (Default: ```0```)
 

docs/content/reference/static-configuration/file.toml

@@ -147,6 +147,12 @@
     labelSelector = "foobar"
     throttleDuration = "42s"
     experimentalChannel = true
+    [providers.kubernetesGateway.statusAddress]
+      ip = "foobar"
+      hostname = "foobar"
+      [providers.kubernetesGateway.statusAddress.service]
+        name = "foobar"
+        namespace = "foobar"
   [providers.rest]
     insecure = true
   [providers.consulCatalog]

docs/content/reference/static-configuration/file.yaml

@@ -164,6 +164,12 @@ providers:
     labelSelector: foobar
     throttleDuration: 42s
     experimentalChannel: true
+    statusAddress:
+      ip: foobar
+      hostname: foobar
+      service:
+        name: foobar
+        namespace: foobar
   rest:
     insecure: true
   consulCatalog:

pkg/provider/kubernetes/gateway/fixtures/services.yml

@@ -269,3 +269,16 @@ spec:
     - protocol: TCP
       port: 10000
       name: tcp-2
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: status-address
+  namespace: default
+
+status:
+  loadBalancer:
+    ingress:
+      - hostname: foo.bar
+      - ip: 1.2.3.4

pkg/provider/kubernetes/gateway/kubernetes.go

@@ -58,6 +58,7 @@ type Provider struct {
 	LabelSelector       string              `description:"Kubernetes label selector to select specific GatewayClasses." json:"labelSelector,omitempty" toml:"labelSelector,omitempty" yaml:"labelSelector,omitempty" export:"true"`
 	ThrottleDuration    ptypes.Duration     `description:"Kubernetes refresh throttle duration" json:"throttleDuration,omitempty" toml:"throttleDuration,omitempty" yaml:"throttleDuration,omitempty" export:"true"`
 	ExperimentalChannel bool                `description:"Toggles Experimental Channel resources support (TCPRoute, TLSRoute...)." json:"experimentalChannel,omitempty" toml:"experimentalChannel,omitempty" yaml:"experimentalChannel,omitempty" export:"true"`
+	StatusAddress       *StatusAddress      `description:"Defines the Kubernetes Gateway status address." json:"statusAddress,omitempty" toml:"statusAddress,omitempty" yaml:"statusAddress,omitempty" export:"true"`
 
 	EntryPoints map[string]Entrypoint `json:"-" toml:"-" yaml:"-" label:"-" file:"-"`
 
@@ -71,6 +72,19 @@ type Provider struct {
 	routerTransform k8s.RouterTransform
 }
 
+// StatusAddress holds the Gateway Status address configuration.
+type StatusAddress struct {
+	IP       string     `description:"IP used to set Kubernetes Gateway status address." json:"ip,omitempty" toml:"ip,omitempty" yaml:"ip,omitempty"`
+	Hostname string     `description:"Hostname used for Kubernetes Gateway status address." json:"hostname,omitempty" toml:"hostname,omitempty" yaml:"hostname,omitempty"`
+	Service  ServiceRef `description:"Published Kubernetes Service to copy status addresses from." json:"service,omitempty" toml:"service,omitempty" yaml:"service,omitempty"`
+}
+
+// ServiceRef holds a Kubernetes service reference.
+type ServiceRef struct {
+	Name      string `description:"Name of the Kubernetes service." json:"name,omitempty" toml:"name,omitempty" yaml:"name,omitempty"`
+	Namespace string `description:"Namespace of the Kubernetes service." json:"namespace,omitempty" toml:"namespace,omitempty" yaml:"namespace,omitempty"`
+}
+
 // BuildFilterFunc returns the name of the filter and the related dynamic.Middleware if needed.
 type BuildFilterFunc func(name, namespace string) (string, *dynamic.Middleware, error)
 
@@ -368,9 +382,14 @@ func (p *Provider) createGatewayConf(ctx context.Context, client Client, gateway
 	// and cannot be configured on the Gateway.
 	listenerStatuses := p.fillGatewayConf(ctx, client, gateway, conf, tlsConfigs)
 
-	gatewayStatus, errG := p.makeGatewayStatus(gateway, listenerStatuses)
+	addresses, err := p.gatewayAddresses(client)
+	if err != nil {
+		return nil, fmt.Errorf("get Gateway status addresses: %w", err)
+	}
 
-	err := client.UpdateGatewayStatus(gateway, gatewayStatus)
+	gatewayStatus, errG := p.makeGatewayStatus(gateway, listenerStatuses, addresses)
+
+	err = client.UpdateGatewayStatus(gateway, gatewayStatus)
 	if err != nil {
 		return nil, fmt.Errorf("an error occurred while updating gateway status: %w", err)
 	}
@@ -618,11 +637,8 @@ func (p *Provider) fillGatewayConf(ctx context.Context, client Client, gateway *
 	return listenerStatuses
 }
 
-func (p *Provider) makeGatewayStatus(gateway *gatev1.Gateway, listenerStatuses []gatev1.ListenerStatus) (gatev1.GatewayStatus, error) {
-	// As Status.Addresses are not implemented yet, we initialize an empty array to follow the API expectations.
-	gatewayStatus := gatev1.GatewayStatus{
-		Addresses: []gatev1.GatewayStatusAddress{},
-	}
+func (p *Provider) makeGatewayStatus(gateway *gatev1.Gateway, listenerStatuses []gatev1.ListenerStatus, addresses []gatev1.GatewayStatusAddress) (gatev1.GatewayStatus, error) {
+	gatewayStatus := gatev1.GatewayStatus{Addresses: addresses}
 
 	var result error
 	for i, listener := range listenerStatuses {
@@ -701,6 +717,57 @@ func (p *Provider) makeGatewayStatus(gateway *gatev1.Gateway, listenerStatuses [
 	return gatewayStatus, nil
 }
 
+func (p *Provider) gatewayAddresses(client Client) ([]gatev1.GatewayStatusAddress, error) {
+	if p.StatusAddress == nil {
+		return nil, nil
+	}
+
+	if p.StatusAddress.IP != "" {
+		return []gatev1.GatewayStatusAddress{{
+			Type:  ptr.To(gatev1.IPAddressType),
+			Value: p.StatusAddress.IP,
+		}}, nil
+	}
+
+	if p.StatusAddress.Hostname != "" {
+		return []gatev1.GatewayStatusAddress{{
+			Type:  ptr.To(gatev1.HostnameAddressType),
+			Value: p.StatusAddress.Hostname,
+		}}, nil
+	}
+
+	svcRef := p.StatusAddress.Service
+	if svcRef.Name != "" && svcRef.Namespace != "" {
+		svc, exists, err := client.GetService(svcRef.Namespace, svcRef.Name)
+		if err != nil {
+			return nil, fmt.Errorf("unable to get service: %w", err)
+		}
+		if !exists {
+			return nil, fmt.Errorf("could not find a service with name %s in namespace %s", svcRef.Name, svcRef.Namespace)
+		}
+
+		var addresses []gatev1.GatewayStatusAddress
+		for _, addr := range svc.Status.LoadBalancer.Ingress {
+			switch {
+			case addr.IP != "":
+				addresses = append(addresses, gatev1.GatewayStatusAddress{
+					Type:  ptr.To(gatev1.IPAddressType),
+					Value: addr.IP,
+				})
+
+			case addr.Hostname != "":
+				addresses = append(addresses, gatev1.GatewayStatusAddress{
+					Type:  ptr.To(gatev1.HostnameAddressType),
+					Value: addr.Hostname,
+				})
+			}
+		}
+		return addresses, nil
+	}
+
+	return nil, errors.New("empty Gateway status address configuration")
+}
+
 func (p *Provider) entryPointName(port gatev1.PortNumber, protocol gatev1.ProtocolType) (string, error) {
 	portStr := strconv.FormatInt(int64(port), 10)
 

pkg/provider/kubernetes/gateway/kubernetes_test.go

@@ -6296,30 +6296,6 @@ func Test_makeListenerKey(t *testing.T) {
 	}
 }
 
-func hostnamePtr(hostname gatev1.Hostname) *gatev1.Hostname {
-	return &hostname
-}
-
-func groupPtr(group gatev1.Group) *gatev1.Group {
-	return &group
-}
-
-func sectionNamePtr(sectionName gatev1.SectionName) *gatev1.SectionName {
-	return &sectionName
-}
-
-func namespacePtr(namespace gatev1.Namespace) *gatev1.Namespace {
-	return &namespace
-}
-
-func kindPtr(kind gatev1.Kind) *gatev1.Kind {
-	return &kind
-}
-
-func pathMatchTypePtr(p gatev1.PathMatchType) *gatev1.PathMatchType { return &p }
-
-func headerMatchTypePtr(h gatev1.HeaderMatchType) *gatev1.HeaderMatchType { return &h }
-
 func Test_referenceGrantMatchesFrom(t *testing.T) {
 	testCases := []struct {
 		desc           string
@@ -6558,6 +6534,131 @@ func Test_referenceGrantMatchesTo(t *testing.T) {
 	}
 }
 
+func Test_gatewayAddresses(t *testing.T) {
+	testCases := []struct {
+		desc          string
+		statusAddress *StatusAddress
+		paths         []string
+		wantErr       require.ErrorAssertionFunc
+		want          []gatev1.GatewayStatusAddress
+	}{
+		{
+			desc:    "nothing",
+			wantErr: require.NoError,
+		},
+		{
+			desc:          "empty configuration",
+			statusAddress: &StatusAddress{},
+			wantErr:       require.Error,
+		},
+		{
+			desc: "IP address",
+			statusAddress: &StatusAddress{
+				IP: "1.2.3.4",
+			},
+			wantErr: require.NoError,
+			want: []gatev1.GatewayStatusAddress{
+				{
+					Type:  ptr.To(gatev1.IPAddressType),
+					Value: "1.2.3.4",
+				},
+			},
+		},
+		{
+			desc: "hostname address",
+			statusAddress: &StatusAddress{
+				Hostname: "foo.bar",
+			},
+			wantErr: require.NoError,
+			want: []gatev1.GatewayStatusAddress{
+				{
+					Type:  ptr.To(gatev1.HostnameAddressType),
+					Value: "foo.bar",
+				},
+			},
+		},
+		{
+			desc: "service",
+			statusAddress: &StatusAddress{
+				Service: ServiceRef{
+					Name:      "status-address",
+					Namespace: "default",
+				},
+			},
+			paths:   []string{"services.yml"},
+			wantErr: require.NoError,
+			want: []gatev1.GatewayStatusAddress{
+				{
+					Type:  ptr.To(gatev1.HostnameAddressType),
+					Value: "foo.bar",
+				},
+				{
+					Type:  ptr.To(gatev1.IPAddressType),
+					Value: "1.2.3.4",
+				},
+			},
+		},
+		{
+			desc: "missing service",
+			statusAddress: &StatusAddress{
+				Service: ServiceRef{
+					Name:      "status-address2",
+					Namespace: "default",
+				},
+			},
+			wantErr: require.Error,
+		},
+		{
+			desc: "service without load-balancer status",
+			statusAddress: &StatusAddress{
+				Service: ServiceRef{
+					Name:      "whoamitcp-bar",
+					Namespace: "bar",
+				},
+			},
+			paths:   []string{"services.yml"},
+			wantErr: require.NoError,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			p := Provider{StatusAddress: test.statusAddress}
+
+			got, err := p.gatewayAddresses(newClientMock(test.paths...))
+			test.wantErr(t, err)
+
+			assert.Equal(t, test.want, got)
+		})
+	}
+}
+
+func hostnamePtr(hostname gatev1.Hostname) *gatev1.Hostname {
+	return &hostname
+}
+
+func groupPtr(group gatev1.Group) *gatev1.Group {
+	return &group
+}
+
+func sectionNamePtr(sectionName gatev1.SectionName) *gatev1.SectionName {
+	return &sectionName
+}
+
+func namespacePtr(namespace gatev1.Namespace) *gatev1.Namespace {
+	return &namespace
+}
+
+func kindPtr(kind gatev1.Kind) *gatev1.Kind {
+	return &kind
+}
+
+func pathMatchTypePtr(p gatev1.PathMatchType) *gatev1.PathMatchType { return &p }
+
+func headerMatchTypePtr(h gatev1.HeaderMatchType) *gatev1.HeaderMatchType { return &h }
+
 func objectNamePtr(objectName gatev1.ObjectName) *gatev1.ObjectName {
 	return &objectName
 }