Allow config of additonal CircuitBreaker params

pkg/provider/kubernetes/crd/kubernetes.go

@@ -243,6 +243,12 @@ func (p *Provider) loadConfigurationFromCRD(ctx context.Context, client Client)
 			continue
 		}
 
+		circuitBreaker, err := createCircuitBreakerMiddleware(middleware.Spec.CircuitBreaker)
+		if err != nil {
+			log.FromContext(ctxMid).Errorf("Error while reading circuit breaker middleware: %v", err)
+			continue
+		}
+
 		conf.HTTP.Middlewares[id] = &dynamic.Middleware{
 			AddPrefix:         middleware.Spec.AddPrefix,
 			StripPrefix:       middleware.Spec.StripPrefix,
@@ -261,7 +267,7 @@ func (p *Provider) loadConfigurationFromCRD(ctx context.Context, client Client)
 			ForwardAuth:       forwardAuth,
 			InFlightReq:       middleware.Spec.InFlightReq,
 			Buffering:         middleware.Spec.Buffering,
-			CircuitBreaker:    middleware.Spec.CircuitBreaker,
+			CircuitBreaker:    circuitBreaker,
 			Compress:          middleware.Spec.Compress,
 			PassTLSClientCert: middleware.Spec.PassTLSClientCert,
 			Retry:             retry,
@@ -425,6 +431,35 @@ func createPluginMiddleware(plugins map[string]apiextensionv1.JSON) (map[string]
 	return pc, nil
 }
 
+func createCircuitBreakerMiddleware(circuitBreaker *v1alpha1.CircuitBreaker) (*dynamic.CircuitBreaker, error) {
+	if circuitBreaker == nil {
+		return nil, nil
+	}
+
+	cb := &dynamic.CircuitBreaker{Expression: circuitBreaker.Expression}
+	cb.SetDefaults()
+
+	if circuitBreaker.CheckPeriod != nil {
+		if err := cb.CheckPeriod.Set(circuitBreaker.CheckPeriod.String()); err != nil {
+			return nil, err
+		}
+	}
+
+	if circuitBreaker.FallbackDuration != nil {
+		if err := cb.FallbackDuration.Set(circuitBreaker.FallbackDuration.String()); err != nil {
+			return nil, err
+		}
+	}
+
+	if circuitBreaker.RecoveryDuration != nil {
+		if err := cb.RecoveryDuration.Set(circuitBreaker.RecoveryDuration.String()); err != nil {
+			return nil, err
+		}
+	}
+
+	return cb, nil
+}
+
 func createRateLimitMiddleware(rateLimit *v1alpha1.RateLimit) (*dynamic.RateLimit, error) {
 	if rateLimit == nil {
 		return nil, nil

pkg/provider/kubernetes/crd/traefik/v1alpha1/middleware.go

@@ -40,7 +40,7 @@ type MiddlewareSpec struct {
 	ForwardAuth       *ForwardAuth                   `json:"forwardAuth,omitempty"`
 	InFlightReq       *dynamic.InFlightReq           `json:"inFlightReq,omitempty"`
 	Buffering         *dynamic.Buffering             `json:"buffering,omitempty"`
-	CircuitBreaker    *dynamic.CircuitBreaker        `json:"circuitBreaker,omitempty"`
+	CircuitBreaker    *CircuitBreaker                `json:"circuitBreaker,omitempty"`
 	Compress          *dynamic.Compress              `json:"compress,omitempty"`
 	PassTLSClientCert *dynamic.PassTLSClientCert     `json:"passTLSClientCert,omitempty"`
 	Retry             *Retry                         `json:"retry,omitempty"`
@@ -59,6 +59,20 @@ type ErrorPage struct {
 
 // +k8s:deepcopy-gen=true
 
+// CircuitBreaker holds the circuit breaker configuration.
+type CircuitBreaker struct {
+	// Expression is the condition that triggers the tripped state.
+	Expression string `json:"expression,omitempty" toml:"expression,omitempty" yaml:"expression,omitempty" export:"true"`
+	// CheckPeriod is the interval between successive checks of the circuit breaker condition (when in standby state).
+	CheckPeriod *intstr.IntOrString `json:"checkPeriod,omitempty" toml:"checkPeriod,omitempty" yaml:"checkPeriod,omitempty" export:"true"`
+	// FallbackDuration is the duration for which the circuit breaker will wait before trying to recover (from a tripped state).
+	FallbackDuration *intstr.IntOrString `json:"fallbackDuration,omitempty" toml:"fallbackDuration,omitempty" yaml:"fallbackDuration,omitempty" export:"true"`
+	// RecoveryDuration is the duration for which the circuit breaker will try to recover (as soon as it is in recovering state).
+	RecoveryDuration *intstr.IntOrString `json:"recoveryDuration,omitempty" toml:"recoveryDuration,omitempty" yaml:"recoveryDuration,omitempty" export:"true"`
+}
+
+// +k8s:deepcopy-gen=true
+
 // Chain holds a chain of middlewares.
 type Chain struct {
 	Middlewares []MiddlewareRef `json:"middlewares,omitempty"`

pkg/provider/kubernetes/crd/traefik/v1alpha1/zz_generated.deepcopy.go

@@ -74,6 +74,37 @@ func (in *Chain) DeepCopy() *Chain {
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *CircuitBreaker) DeepCopyInto(out *CircuitBreaker) {
+	*out = *in
+	if in.CheckPeriod != nil {
+		in, out := &in.CheckPeriod, &out.CheckPeriod
+		*out = new(intstr.IntOrString)
+		**out = **in
+	}
+	if in.FallbackDuration != nil {
+		in, out := &in.FallbackDuration, &out.FallbackDuration
+		*out = new(intstr.IntOrString)
+		**out = **in
+	}
+	if in.RecoveryDuration != nil {
+		in, out := &in.RecoveryDuration, &out.RecoveryDuration
+		*out = new(intstr.IntOrString)
+		**out = **in
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CircuitBreaker.
+func (in *CircuitBreaker) DeepCopy() *CircuitBreaker {
+	if in == nil {
+		return nil
+	}
+	out := new(CircuitBreaker)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *ClientAuth) DeepCopyInto(out *ClientAuth) {
 	*out = *in
@@ -714,8 +745,8 @@ func (in *MiddlewareSpec) DeepCopyInto(out *MiddlewareSpec) {
 	}
 	if in.CircuitBreaker != nil {
 		in, out := &in.CircuitBreaker, &out.CircuitBreaker
-		*out = new(dynamic.CircuitBreaker)
-		**out = **in
+		*out = new(CircuitBreaker)
+		(*in).DeepCopyInto(*out)
 	}
 	if in.Compress != nil {
 		in, out := &in.Compress, &out.Compress