Merge pull request #1127 from candita/NE-585-HealthCheckInterval

NE-585 Make ROUTER_BACKEND_CHECK_INTERVAL configurable

operator/v1/0000_50_ingress-operator_00-ingresscontroller.crd.yaml

@@ -1126,6 +1126,24 @@ spec:
                     format: int32
                     minimum: 4096
                     type: integer
+                  healthCheckInterval:
+                    description: "healthCheckInterval defines how long the router
+                      waits between two consecutive health checks on its configured
+                      backends.  This value is applied globally as a default for all
+                      routes, but may be overridden per-route by the route annotation
+                      \"router.openshift.io/haproxy.health.check.interval\". \n Setting
+                      this to less than 5s can cause excess traffic due to too frequent
+                      TCP health checks and accompanying SYN packet storms.  Alternatively,
+                      setting this too high can result in increased latency, due to
+                      backend servers that are no longer available, but haven't yet
+                      been detected as such. \n An empty or zero healthCheckInterval
+                      means no opinion and IngressController chooses a default, which
+                      is subject to change over time. Currently the default healthCheckInterval
+                      value is 5s. \n Currently the minimum allowed value is 1s and
+                      the maximum allowed value is 2147483647ms (24.85 days).  Both
+                      are subject to change over time."
+                    format: duration
+                    type: string
                   serverFinTimeout:
                     description: "serverFinTimeout defines how long a connection will
                       be held open while waiting for the server/backend response to

operator/v1/types_ingress.go

@@ -1306,6 +1306,28 @@ type IngressControllerTuningOptions struct {
 	// +kubebuilder:validation:Format=duration
 	// +optional
 	TLSInspectDelay *metav1.Duration `json:"tlsInspectDelay,omitempty"`
+
+	// healthCheckInterval defines how long the router waits between two consecutive
+	// health checks on its configured backends.  This value is applied globally as
+	// a default for all routes, but may be overridden per-route by the route annotation
+	// "router.openshift.io/haproxy.health.check.interval".
+	//
+	// Setting this to less than 5s can cause excess traffic due to too frequent
+	// TCP health checks and accompanying SYN packet storms.  Alternatively, setting
+	// this too high can result in increased latency, due to backend servers that are no
+	// longer available, but haven't yet been detected as such.
+	//
+	// An empty or zero healthCheckInterval means no opinion and IngressController chooses
+	// a default, which is subject to change over time.
+	// Currently the default healthCheckInterval value is 5s.
+	//
+	// Currently the minimum allowed value is 1s and the maximum allowed value is
+	// 2147483647ms (24.85 days).  Both are subject to change over time.
+	//
+	// +kubebuilder:validation:Optional
+	// +kubebuilder:validation:Format=duration
+	// +optional
+	HealthCheckInterval *metav1.Duration `json:"healthCheckInterval,omitempty"`
 }
 
 // HTTPEmptyRequestsPolicy indicates how HTTP connections for which no request