mirror of https://github.com/knative/caching.git
98 lines
3.0 KiB
Go
98 lines
3.0 KiB
Go
/*
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Copyright 2021 The Knative 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 environment
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import (
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"flag"
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"fmt"
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"log"
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"math"
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"os"
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"strconv"
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"k8s.io/client-go/rest"
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"k8s.io/client-go/tools/clientcmd"
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clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
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)
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// ClientConfig holds the information about the environment and can be configured with flags
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type ClientConfig struct {
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Cluster string // K8s cluster (defaults to cluster in kubeconfig)
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ServerURL string // ServerURL - The address of the Kubernetes API server. Overrides any value in kubeconfig.
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Burst int // Burst - Maximum burst for throttle.
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QPS float64 // QPS - Maximum QPS to the server from the client.
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Kubeconfig string // Kubeconfig - Path to a kubeconfig. Current casing is present for backwards compatibility
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}
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func (c *ClientConfig) InitFlags(fs *flag.FlagSet) {
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fs.StringVar(&c.Cluster, "cluster", "", "Defaults to the current cluster in kubeconfig.")
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fs.StringVar(&c.ServerURL, "server", "",
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"The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.")
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fs.StringVar(&c.Kubeconfig, "kubeconfig", os.Getenv("KUBECONFIG"),
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"Path to a kubeconfig. Only required if out-of-cluster.")
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fs.IntVar(&c.Burst, "kube-api-burst", int(envVarOrDefault("KUBE_API_BURST", 0)), "Maximum burst for throttle.")
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fs.Float64Var(&c.QPS, "kube-api-qps", envVarOrDefault("KUBE_API_QPS", 0.0), "Maximum QPS to the server from the client.")
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}
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func envVarOrDefault(key string, val float64) float64 {
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var err error
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if v := os.Getenv(key); v != "" {
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if val, err = strconv.ParseFloat(v, 64); err != nil {
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log.Fatal(err)
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}
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}
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return val
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}
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func (c *ClientConfig) GetRESTConfig() (*rest.Config, error) {
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if c.Burst < 0 {
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return nil, fmt.Errorf("provided burst value %d must be > 0", c.Burst)
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}
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if c.QPS < 0 || c.QPS > math.MaxFloat32 {
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return nil, fmt.Errorf("provided QPS value %f must be >0 and <3.4+e38", c.QPS)
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}
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loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
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overrides := &clientcmd.ConfigOverrides{}
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if c.Kubeconfig != "" {
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loadingRules.ExplicitPath = c.Kubeconfig
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}
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if c.Cluster != "" {
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overrides.Context = clientcmdapi.Context{Cluster: c.Cluster}
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} else if c.ServerURL != "" {
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overrides.ClusterInfo = clientcmdapi.Cluster{Server: c.ServerURL}
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}
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config, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
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loadingRules,
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overrides,
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).ClientConfig()
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if err != nil {
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return nil, fmt.Errorf("failed to create client config: %w", err)
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}
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config.QPS = float32(c.QPS)
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config.Burst = c.Burst
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return config, nil
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}
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