Throttle Kubernetes config refresh

This commit is contained in:
Ben Weissmann 2019-08-30 06:16:04 -04:00 committed by Traefiker Bot
parent 6e8138e19b
commit 43af0b051f
8 changed files with 169 additions and 13 deletions

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@ -168,6 +168,27 @@ Value of `kubernetes.io/ingress.class` annotation that identifies Ingress object
If the parameter is non-empty, only Ingresses containing an annotation with the same value are processed.
Otherwise, Ingresses missing the annotation, having an empty value, or the value `traefik` are processed.
### `throttleDuration`
_Optional, Default: 0 (no throttling)_
```toml tab="File (TOML)"
[providers.kubernetesCRD]
throttleDuration = "10s"
# ...
```
```yaml tab="File (YAML)"
providers:
kubernetesCRD:
throttleDuration: "10s"
# ...
```
```bash tab="CLI"
--providers.kubernetescrd.throttleDuration="10s"
```
## Resource Configuration
If you're in a hurry, maybe you'd rather go through the [dynamic](../reference/dynamic-configuration/kubernetes-crd.md) configuration reference.

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@ -305,6 +305,27 @@ providers:
Published Kubernetes Service to copy status from.
### `throttleDuration`
_Optional, Default: 0 (no throttling)_
```toml tab="File (TOML)"
[providers.kubernetesIngress]
throttleDuration = "10s"
# ...
```
```yaml tab="File (YAML)"
providers:
kubernetesIngress:
throttleDuration: "10s"
# ...
```
```bash tab="CLI"
--providers.kubernetesingress.throttleDuration="10s"
```
## Further
If one wants to know more about the various aspects of the Ingress spec that Traefik supports, many examples of Ingresses definitions are located in the tests [data](https://github.com/containous/traefik/tree/v2.0/pkg/provider/kubernetes/ingress/fixtures) of the Traefik repository.

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@ -46,7 +46,7 @@ Activate dashboard. (Default: ```true```)
Enable additional endpoints for debugging and profiling. (Default: ```false```)
`--api.insecure`:
Activate API on an insecure entryPoints named traefik. (Default: ```false```)
Activate API directly on the entryPoint named traefik. (Default: ```false```)
`--certificatesresolvers.<name>`:
Certificates resolvers configuration. (Default: ```false```)
@ -312,6 +312,9 @@ Kubernetes label selector to use.
`--providers.kubernetescrd.namespaces`:
Kubernetes namespaces.
`--providers.kubernetescrd.throttleduration`:
Ingress refresh throttle duration (Default: ```0```)
`--providers.kubernetescrd.token`:
Kubernetes bearer token (not needed for in-cluster client).
@ -345,6 +348,9 @@ Kubernetes Ingress label selector to use.
`--providers.kubernetesingress.namespaces`:
Kubernetes namespaces.
`--providers.kubernetesingress.throttleduration`:
Ingress refresh throttle duration (Default: ```0```)
`--providers.kubernetesingress.token`:
Kubernetes bearer token (not needed for in-cluster client).
@ -445,7 +451,7 @@ Watch provider. (Default: ```true```)
Enable Rest backend with default settings. (Default: ```false```)
`--providers.rest.insecure`:
Activate REST Provider on an insecure entryPoints named traefik. (Default: ```false```)
Activate REST Provider directly on the entryPoint named traefik. (Default: ```false```)
`--serverstransport.forwardingtimeouts.dialtimeout`:
The amount of time to wait until a connection to a backend server can be established. If zero, no timeout exists. (Default: ```30```)

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@ -46,7 +46,7 @@ Activate dashboard. (Default: ```true```)
Enable additional endpoints for debugging and profiling. (Default: ```false```)
`TRAEFIK_API_INSECURE`:
Activate API on an insecure entryPoints named traefik. (Default: ```false```)
Activate API directly on the entryPoint named traefik. (Default: ```false```)
`TRAEFIK_CERTIFICATESRESOLVERS_<NAME>`:
Certificates resolvers configuration. (Default: ```false```)
@ -312,6 +312,9 @@ Kubernetes label selector to use.
`TRAEFIK_PROVIDERS_KUBERNETESCRD_NAMESPACES`:
Kubernetes namespaces.
`TRAEFIK_PROVIDERS_KUBERNETESCRD_THROTTLEDURATION`:
Ingress refresh throttle duration (Default: ```0```)
`TRAEFIK_PROVIDERS_KUBERNETESCRD_TOKEN`:
Kubernetes bearer token (not needed for in-cluster client).
@ -345,6 +348,9 @@ Kubernetes Ingress label selector to use.
`TRAEFIK_PROVIDERS_KUBERNETESINGRESS_NAMESPACES`:
Kubernetes namespaces.
`TRAEFIK_PROVIDERS_KUBERNETESINGRESS_THROTTLEDURATION`:
Ingress refresh throttle duration (Default: ```0```)
`TRAEFIK_PROVIDERS_KUBERNETESINGRESS_TOKEN`:
Kubernetes bearer token (not needed for in-cluster client).
@ -445,7 +451,7 @@ Watch provider. (Default: ```true```)
Enable Rest backend with default settings. (Default: ```false```)
`TRAEFIK_PROVIDERS_REST_INSECURE`:
Activate REST Provider on an insecure entryPoints named traefik. (Default: ```false```)
Activate REST Provider directly on the entryPoint named traefik. (Default: ```false```)
`TRAEFIK_SERVERSTRANSPORT_FORWARDINGTIMEOUTS_DIALTIMEOUT`:
The amount of time to wait until a connection to a backend server can be established. If zero, no timeout exists. (Default: ```30```)

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@ -83,6 +83,7 @@
namespaces = ["foobar", "foobar"]
labelSelector = "foobar"
ingressClass = "foobar"
throttleDuration = "10s"
[providers.kubernetesIngress.ingressEndpoint]
ip = "foobar"
hostname = "foobar"
@ -95,6 +96,7 @@
namespaces = ["foobar", "foobar"]
labelSelector = "foobar"
ingressClass = "foobar"
throttleDuration = "10s"
[providers.rest]
insecure = true
[providers.rancher]

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@ -88,6 +88,7 @@ providers:
- foobar
labelSelector: foobar
ingressClass: foobar
throttleDuration: 10s
ingressEndpoint:
ip: foobar
hostname: foobar
@ -102,6 +103,7 @@ providers:
- foobar
labelSelector: foobar
ingressClass: foobar
throttleDuration: 10s
rest:
insecure: true
rancher:

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@ -20,6 +20,7 @@ import (
"github.com/containous/traefik/v2/pkg/provider/kubernetes/crd/traefik/v1alpha1"
"github.com/containous/traefik/v2/pkg/safe"
"github.com/containous/traefik/v2/pkg/tls"
"github.com/containous/traefik/v2/pkg/types"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/labels"
)
@ -38,6 +39,7 @@ type Provider struct {
Namespaces []string `description:"Kubernetes namespaces." json:"namespaces,omitempty" toml:"namespaces,omitempty" yaml:"namespaces,omitempty" export:"true"`
LabelSelector string `description:"Kubernetes label selector to use." json:"labelSelector,omitempty" toml:"labelSelector,omitempty" yaml:"labelSelector,omitempty" export:"true"`
IngressClass string `description:"Value of kubernetes.io/ingress.class annotation to watch for." json:"ingressClass,omitempty" toml:"ingressClass,omitempty" yaml:"ingressClass,omitempty" export:"true"`
ThrottleDuration types.Duration `description:"Ingress refresh throttle duration" json:"throttleDuration,omitempty" toml:"throttleDuration,omitempty" yaml:"throttleDuration,omitempty"`
lastConfiguration safe.Safe
}
@ -95,6 +97,7 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
stopWatch := make(chan struct{}, 1)
defer close(stopWatch)
eventsChan, err := k8sClient.WatchAll(p.Namespaces, stopWatch)
if err != nil {
logger.Errorf("Error watching kubernetes events: %v", err)
timer := time.NewTimer(1 * time.Second)
@ -105,11 +108,20 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
return nil
}
}
throttleDuration := time.Duration(p.ThrottleDuration)
eventsChanToRead := throttleEvents(ctxLog, throttleDuration, stop, eventsChan)
for {
select {
case <-stop:
return nil
case event := <-eventsChan:
case event := <-eventsChanToRead:
// Note that event is the *first* event that came in during this
// throttling interval -- if we're hitting our throttle, we may have
// dropped events. This is fine, because we don't treat different
// event types differently. But if we do in the future, we'll need to
// track more information about the dropped events.
conf := p.loadConfigurationFromCRD(ctxLog, k8sClient)
if reflect.DeepEqual(p.lastConfiguration.Get(), conf) {
@ -121,6 +133,11 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
Configuration: conf,
}
}
// If we're throttling, we sleep here for the throttle duration to
// enforce that we don't refresh faster than our throttle. time.Sleep
// returns immediately if p.ThrottleDuration is 0 (no throttle).
time.Sleep(throttleDuration)
}
}
}
@ -587,3 +604,36 @@ func getCABlocks(secret *corev1.Secret, namespace, secretName string) (string, e
return cert, nil
}
func throttleEvents(ctx context.Context, throttleDuration time.Duration, stop chan bool, eventsChan <-chan interface{}) chan interface{} {
if throttleDuration == 0 {
return nil
}
// Create a buffered channel to hold the pending event (if we're delaying processing the event due to throttling)
eventsChanBuffered := make(chan interface{}, 1)
// Run a goroutine that reads events from eventChan and does a
// non-blocking write to pendingEvent. This guarantees that writing to
// eventChan will never block, and that pendingEvent will have
// something in it if there's been an event since we read from that channel.
go func() {
for {
select {
case <-stop:
return
case nextEvent := <-eventsChan:
select {
case eventsChanBuffered <- nextEvent:
default:
// We already have an event in eventsChanBuffered, so we'll
// do a refresh as soon as our throttle allows us to. It's fine
// to drop the event and keep whatever's in the buffer -- we
// don't do different things for different events
log.FromContext(ctx).Debugf("Dropping event kind %T due to throttling", nextEvent)
}
}
}
}()
return eventsChanBuffered
}

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@ -18,6 +18,7 @@ import (
"github.com/containous/traefik/v2/pkg/log"
"github.com/containous/traefik/v2/pkg/safe"
"github.com/containous/traefik/v2/pkg/tls"
"github.com/containous/traefik/v2/pkg/types"
corev1 "k8s.io/api/core/v1"
"k8s.io/api/extensions/v1beta1"
"k8s.io/apimachinery/pkg/labels"
@ -39,6 +40,7 @@ type Provider struct {
LabelSelector string `description:"Kubernetes Ingress label selector to use." json:"labelSelector,omitempty" toml:"labelSelector,omitempty" yaml:"labelSelector,omitempty" export:"true"`
IngressClass string `description:"Value of kubernetes.io/ingress.class annotation to watch for." json:"ingressClass,omitempty" toml:"ingressClass,omitempty" yaml:"ingressClass,omitempty" export:"true"`
IngressEndpoint *EndpointIngress `description:"Kubernetes Ingress Endpoint." json:"ingressEndpoint,omitempty" toml:"ingressEndpoint,omitempty" yaml:"ingressEndpoint,omitempty"`
ThrottleDuration types.Duration `description:"Ingress refresh throttle duration" json:"throttleDuration,omitempty" toml:"throttleDuration,omitempty" yaml:"throttleDuration,omitempty"`
lastConfiguration safe.Safe
}
@ -118,11 +120,19 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
}
}
throttleDuration := time.Duration(p.ThrottleDuration)
eventsChanToRead := throttleEvents(ctxLog, throttleDuration, stop, eventsChan)
for {
select {
case <-stop:
return nil
case event := <-eventsChan:
case event := <-eventsChanToRead:
// Note that event is the *first* event that came in during this
// throttling interval -- if we're hitting our throttle, we may have
// dropped events. This is fine, because we don't treat different
// event types differently. But if we do in the future, we'll need to
// track more information about the dropped events.
conf := p.loadConfigurationFromIngresses(ctxLog, k8sClient)
if reflect.DeepEqual(p.lastConfiguration.Get(), conf) {
@ -134,6 +144,11 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
Configuration: conf,
}
}
// If we're throttling, we sleep here for the throttle duration to
// enforce that we don't refresh faster than our throttle. time.Sleep
// returns immediately if p.ThrottleDuration is 0 (no throttle).
time.Sleep(throttleDuration)
}
}
}
@ -478,3 +493,36 @@ func (p *Provider) updateIngressStatus(i *v1beta1.Ingress, k8sClient Client) err
return k8sClient.UpdateIngressStatus(i.Namespace, i.Name, service.Status.LoadBalancer.Ingress[0].IP, service.Status.LoadBalancer.Ingress[0].Hostname)
}
func throttleEvents(ctx context.Context, throttleDuration time.Duration, stop chan bool, eventsChan <-chan interface{}) chan interface{} {
if throttleDuration == 0 {
return nil
}
// Create a buffered channel to hold the pending event (if we're delaying processing the event due to throttling)
eventsChanBuffered := make(chan interface{}, 1)
// Run a goroutine that reads events from eventChan and does a
// non-blocking write to pendingEvent. This guarantees that writing to
// eventChan will never block, and that pendingEvent will have
// something in it if there's been an event since we read from that channel.
go func() {
for {
select {
case <-stop:
return
case nextEvent := <-eventsChan:
select {
case eventsChanBuffered <- nextEvent:
default:
// We already have an event in eventsChanBuffered, so we'll
// do a refresh as soon as our throttle allows us to. It's fine
// to drop the event and keep whatever's in the buffer -- we
// don't do different things for different events
log.FromContext(ctx).Debugf("Dropping event kind %T due to throttling", nextEvent)
}
}
}
}()
return eventsChanBuffered
}