feat(load-balancer): support http timeout-idle annotation

Add the `load-balancer.hetzner.cloud/http-timeout-idle` annotation to
configure the idle timeout for the client and server side of an HTTP/HTTPS
Load Balancer service.

It is documented as the new `duration` type (a Go duration string, e.g. `30s`).

Closes #1233

Author: lukasmetzner

docs/reference/load_balancer_annotations.md

@@ -4,6 +4,7 @@ This page contains all annotations, which can be specified at a Service of type
 
 - Read-only annotations are set by the Cloud Controller Manager.
 - Enums are depicted in the `Type` column and possible options are separated via the pipe symbol `|`.
+- The `duration` type is a Go duration string, i.e. a sequence of decimal numbers each with a unit suffix such as `300ms`, `30s`, `5m` or `1h` (see [`time.ParseDuration`](https://pkg.go.dev/time#ParseDuration)).
 
 | Name | Type | Default | Read-only | Description |
 | --- | --- | --- | --- | --- |
@@ -28,6 +29,7 @@ This page contains all annotations, which can be specified at a Service of type
 | `load-balancer.hetzner.cloud/uses-proxyprotocol` | `bool` | `false` | `No` | Specifies if the Load Balancer services should use the proxy protocol. |
 | `load-balancer.hetzner.cloud/http-cookie-name` | `string` | `-` | `No` | Specifies the cookie name when using  HTTP or HTTPS as protocol. |
 | `load-balancer.hetzner.cloud/http-cookie-lifetime` | `int` | `-` | `No` | Specifies the lifetime of the HTTP cookie. |
+| `load-balancer.hetzner.cloud/http-timeout-idle` | `duration` | `-` | `No` | Specifies the idle timeout for the client and server side. |
 | `load-balancer.hetzner.cloud/certificate-type` | `uploaded \| managed` | `uploaded` | `No` | Defines the type of certificate the Load Balancer should use. |
 | `load-balancer.hetzner.cloud/http-certificates` | `string` | `-` | `No` | A comma separated list of IDs or Names of Certificates assigned to the service. |
 | `load-balancer.hetzner.cloud/http-managed-certificate-name` | `string` | `-` | `No` | Contains the name of the managed certificate to create by the Cloud Controller manager. Ignored if `load-balancer.hetzner.cloud/certificate-type` is missing or set to "uploaded". |

internal/annotation/load_balancer.go

@@ -160,6 +160,12 @@ const (
 	// Type: int
 	LBSvcHTTPCookieLifetime Name = "load-balancer.hetzner.cloud/http-cookie-lifetime"
 
+	// LBSvcHTTPTimeoutIdle specifies the idle timeout for the client and
+	// server side.
+	//
+	// Type: duration
+	LBSvcHTTPTimeoutIdle Name = "load-balancer.hetzner.cloud/http-timeout-idle"
+
 	// LBSvcHTTPCertificateType defines the type of certificate the Load
 	// Balancer should use.
 	//

internal/hcops/load_balancer.go

@@ -1042,6 +1042,7 @@ type hclbServiceOptsBuilder struct {
 		Certificates   []*hcloud.Certificate
 		RedirectHTTP   *bool
 		StickySessions *bool
+		TimeoutIdle    *time.Duration
 	}
 	addHTTP         bool
 	healthCheckOpts struct {
@@ -1115,6 +1116,18 @@ func (b *hclbServiceOptsBuilder) extract() {
 		return nil
 	})
 
+	b.do(func() error {
+		timeout, err := annotation.LBSvcHTTPTimeoutIdle.DurationFromService(b.Service)
+		if errors.Is(err, annotation.ErrNotSet) {
+			return nil
+		}
+		if err != nil {
+			return fmt.Errorf("%s: %w", op, err)
+		}
+		b.httpOpts.TimeoutIdle = &timeout
+		return nil
+	})
+
 	b.do(func() error {
 		certtyp, ok := annotation.LBSvcHTTPCertificateType.StringFromService(b.Service)
 		if ok && certtyp == string(hcloud.CertificateTypeManaged) {
@@ -1367,6 +1380,7 @@ func (b *hclbServiceOptsBuilder) buildAddServiceOpts() (hcloud.LoadBalancerAddSe
 			Certificates:   b.httpOpts.Certificates,
 			RedirectHTTP:   b.httpOpts.RedirectHTTP,
 			StickySessions: b.httpOpts.StickySessions,
+			TimeoutIdle:    b.httpOpts.TimeoutIdle,
 		}
 	}
 	if b.addHealthCheck {
@@ -1421,6 +1435,7 @@ func (b *hclbServiceOptsBuilder) buildUpdateServiceOpts() (hcloud.LoadBalancerUp
 			RedirectHTTP:   b.httpOpts.RedirectHTTP,
 			Certificates:   b.httpOpts.Certificates,
 			StickySessions: b.httpOpts.StickySessions,
+			TimeoutIdle:    b.httpOpts.TimeoutIdle,
 		}
 	}
 	if b.addHealthCheck {

internal/hcops/load_balancer_internal_test.go

@@ -120,6 +120,7 @@ func TestHCLBServiceOptsBuilder(t *testing.T) {
 				annotation.LBSvcHTTPCertificates:   "1,3",
 				annotation.LBSvcRedirectHTTP:       "true",
 				annotation.LBSvcHTTPStickySessions: "true",
+				annotation.LBSvcHTTPTimeoutIdle:    "30s",
 			},
 			expectedAddOpts: hcloud.LoadBalancerAddServiceOpts{
 				ListenPort:      new(82),
@@ -131,6 +132,7 @@ func TestHCLBServiceOptsBuilder(t *testing.T) {
 					Certificates:   []*hcloud.Certificate{{ID: 1}, {ID: 3}},
 					RedirectHTTP:   new(true),
 					StickySessions: new(true),
+					TimeoutIdle:    hcloud.Ptr(30 * time.Second),
 				},
 				HealthCheck: &hcloud.LoadBalancerAddServiceOptsHealthCheck{
 					Protocol: hcloud.LoadBalancerServiceProtocolTCP,
@@ -146,6 +148,7 @@ func TestHCLBServiceOptsBuilder(t *testing.T) {
 					Certificates:   []*hcloud.Certificate{{ID: 1}, {ID: 3}},
 					RedirectHTTP:   new(true),
 					StickySessions: new(true),
+					TimeoutIdle:    hcloud.Ptr(30 * time.Second),
 				},
 				HealthCheck: &hcloud.LoadBalancerUpdateServiceOptsHealthCheck{
 					Protocol: hcloud.LoadBalancerServiceProtocolTCP,

tools/load_balancer_annotations.md.tmpl

@@ -4,5 +4,6 @@ This page contains all annotations, which can be specified at a Service of type
 
 - Read-only annotations are set by the Cloud Controller Manager.
 - Enums are depicted in the `Type` column and possible options are separated via the pipe symbol `|`.
+- The `duration` type is a Go duration string, i.e. a sequence of decimal numbers each with a unit suffix such as `300ms`, `30s`, `5m` or `1h` (see [`time.ParseDuration`](https://pkg.go.dev/time#ParseDuration)).
 
 {{.ConstTable}}