94 lines
3.1 KiB
Go
94 lines
3.1 KiB
Go
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/*
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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 imagepolicy contains an admission controller that configures a webhook to which policy
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// decisions are delegated.
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package imagepolicy
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import (
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"fmt"
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"time"
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"github.com/golang/glog"
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)
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const (
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defaultRetryBackoff = time.Duration(500) * time.Millisecond
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minRetryBackoff = time.Duration(1)
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maxRetryBackoff = time.Duration(5) * time.Minute
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defaultAllowTTL = time.Duration(5) * time.Minute
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defaultDenyTTL = time.Duration(30) * time.Second
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minAllowTTL = time.Duration(1) * time.Second
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maxAllowTTL = time.Duration(30) * time.Minute
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minDenyTTL = time.Duration(1) * time.Second
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maxDenyTTL = time.Duration(30) * time.Minute
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useDefault = time.Duration(0) //sentinel for using default TTL
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disableTTL = time.Duration(-1) //sentinel for disabling a TTL
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)
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// imagePolicyWebhookConfig holds config data for imagePolicyWebhook
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type imagePolicyWebhookConfig struct {
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KubeConfigFile string `json:"kubeConfigFile"`
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AllowTTL time.Duration `json:"allowTTL"`
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DenyTTL time.Duration `json:"denyTTL"`
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RetryBackoff time.Duration `json:"retryBackoff"`
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DefaultAllow bool `json:"defaultAllow"`
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}
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// AdmissionConfig holds config data for admission controllers
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type AdmissionConfig struct {
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ImagePolicyWebhook imagePolicyWebhookConfig `json:"imagePolicy"`
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}
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func normalizeWebhookConfig(config *imagePolicyWebhookConfig) (err error) {
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config.RetryBackoff, err = normalizeConfigDuration("backoff", time.Millisecond, config.RetryBackoff, minRetryBackoff, maxRetryBackoff, defaultRetryBackoff)
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if err != nil {
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return err
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}
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config.AllowTTL, err = normalizeConfigDuration("allow cache", time.Second, config.AllowTTL, minAllowTTL, maxAllowTTL, defaultAllowTTL)
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if err != nil {
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return err
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}
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config.DenyTTL, err = normalizeConfigDuration("deny cache", time.Second, config.DenyTTL, minDenyTTL, maxDenyTTL, defaultDenyTTL)
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if err != nil {
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return err
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}
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return nil
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}
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func normalizeConfigDuration(name string, scale, value, min, max, defaultValue time.Duration) (time.Duration, error) {
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// disable with -1 sentinel
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if value == disableTTL {
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glog.V(2).Infof("image policy webhook %s disabled", name)
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return time.Duration(0), nil
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}
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// use defualt with 0 sentinel
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if value == useDefault {
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glog.V(2).Infof("image policy webhook %s using default value", name)
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return defaultValue, nil
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}
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// convert to s; unmarshalling gives ns
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value *= scale
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// check value is within range
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if value <= min || value > max {
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return value, fmt.Errorf("valid value is between %v and %v, got %v", min, max, value)
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}
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return value, nil
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}
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