mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-05 12:40:20 +00:00
34fc1d847e
to v1.18.0 Signed-off-by: Humble Chirammal <hchiramm@redhat.com>
152 lines
5.7 KiB
Go
152 lines
5.7 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// Package webhook implements a generic HTTP webhook plugin.
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package webhook
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import (
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"context"
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"fmt"
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"time"
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apierrors "k8s.io/apimachinery/pkg/api/errors"
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"k8s.io/apimachinery/pkg/runtime"
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"k8s.io/apimachinery/pkg/runtime/schema"
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"k8s.io/apimachinery/pkg/runtime/serializer"
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"k8s.io/apimachinery/pkg/util/net"
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utilnet "k8s.io/apimachinery/pkg/util/net"
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"k8s.io/apimachinery/pkg/util/wait"
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"k8s.io/client-go/rest"
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"k8s.io/client-go/tools/clientcmd"
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)
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// defaultRequestTimeout is set for all webhook request. This is the absolute
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// timeout of the HTTP request, including reading the response body.
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const defaultRequestTimeout = 30 * time.Second
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// GenericWebhook defines a generic client for webhooks with commonly used capabilities,
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// such as retry requests.
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type GenericWebhook struct {
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RestClient *rest.RESTClient
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InitialBackoff time.Duration
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ShouldRetry func(error) bool
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}
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// DefaultShouldRetry is a default implementation for the GenericWebhook ShouldRetry function property.
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// If the error reason is one of: networking (connection reset) or http (InternalServerError (500), GatewayTimeout (504), TooManyRequests (429)),
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// or apierrors.SuggestsClientDelay() returns true, then the function advises a retry.
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// Otherwise it returns false for an immediate fail.
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func DefaultShouldRetry(err error) bool {
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// these errors indicate a transient error that should be retried.
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if net.IsConnectionReset(err) || apierrors.IsInternalError(err) || apierrors.IsTimeout(err) || apierrors.IsTooManyRequests(err) {
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return true
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}
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// if the error sends the Retry-After header, we respect it as an explicit confirmation we should retry.
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if _, shouldRetry := apierrors.SuggestsClientDelay(err); shouldRetry {
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return true
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}
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return false
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}
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// NewGenericWebhook creates a new GenericWebhook from the provided kubeconfig file.
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func NewGenericWebhook(scheme *runtime.Scheme, codecFactory serializer.CodecFactory, kubeConfigFile string, groupVersions []schema.GroupVersion, initialBackoff time.Duration, customDial utilnet.DialFunc) (*GenericWebhook, error) {
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return newGenericWebhook(scheme, codecFactory, kubeConfigFile, groupVersions, initialBackoff, defaultRequestTimeout, customDial)
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}
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func newGenericWebhook(scheme *runtime.Scheme, codecFactory serializer.CodecFactory, kubeConfigFile string, groupVersions []schema.GroupVersion, initialBackoff, requestTimeout time.Duration, customDial utilnet.DialFunc) (*GenericWebhook, error) {
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for _, groupVersion := range groupVersions {
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if !scheme.IsVersionRegistered(groupVersion) {
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return nil, fmt.Errorf("webhook plugin requires enabling extension resource: %s", groupVersion)
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}
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}
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loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
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loadingRules.ExplicitPath = kubeConfigFile
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loader := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{})
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clientConfig, err := loader.ClientConfig()
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if err != nil {
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return nil, err
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}
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// Kubeconfigs can't set a timeout, this can only be set through a command line flag.
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//
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// https://github.com/kubernetes/client-go/blob/master/tools/clientcmd/overrides.go
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//
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// Set this to something reasonable so request to webhooks don't hang forever.
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clientConfig.Timeout = requestTimeout
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// Avoid client-side rate limiting talking to the webhook backend.
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// Rate limiting should happen when deciding how many requests to serve.
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clientConfig.QPS = -1
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codec := codecFactory.LegacyCodec(groupVersions...)
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clientConfig.ContentConfig.NegotiatedSerializer = serializer.NegotiatedSerializerWrapper(runtime.SerializerInfo{Serializer: codec})
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clientConfig.Dial = customDial
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restClient, err := rest.UnversionedRESTClientFor(clientConfig)
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if err != nil {
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return nil, err
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}
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return &GenericWebhook{restClient, initialBackoff, DefaultShouldRetry}, nil
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}
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// WithExponentialBackoff will retry webhookFn() up to 5 times with exponentially increasing backoff when
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// it returns an error for which this GenericWebhook's ShouldRetry function returns true, confirming it to
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// be retriable. If no ShouldRetry has been defined for the webhook, then the default one is used (DefaultShouldRetry).
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func (g *GenericWebhook) WithExponentialBackoff(ctx context.Context, webhookFn func() rest.Result) rest.Result {
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var result rest.Result
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shouldRetry := g.ShouldRetry
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if shouldRetry == nil {
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shouldRetry = DefaultShouldRetry
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}
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WithExponentialBackoff(ctx, g.InitialBackoff, func() error {
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result = webhookFn()
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return result.Error()
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}, shouldRetry)
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return result
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}
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// WithExponentialBackoff will retry webhookFn up to 5 times with exponentially increasing backoff when
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// it returns an error for which shouldRetry returns true, confirming it to be retriable.
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func WithExponentialBackoff(ctx context.Context, initialBackoff time.Duration, webhookFn func() error, shouldRetry func(error) bool) error {
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backoff := wait.Backoff{
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Duration: initialBackoff,
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Factor: 1.5,
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Jitter: 0.2,
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Steps: 5,
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}
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var err error
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wait.ExponentialBackoff(backoff, func() (bool, error) {
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err = webhookFn()
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if ctx.Err() != nil {
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// we timed out or were cancelled, we should not retry
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return true, err
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}
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if shouldRetry(err) {
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return false, nil
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}
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if err != nil {
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return false, err
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}
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return true, nil
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})
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return err
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}
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