k8s.io/kubernetes@v1.31.0-alpha.0.0.20240520171757-56147500dadc/cmd/kube-scheduler/app/options/configfile.go (about)

     1  /*
     2  Copyright 2018 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package options
    18  
    19  import (
    20  	"bytes"
    21  	"fmt"
    22  	"io"
    23  	"os"
    24  
    25  	"k8s.io/apimachinery/pkg/runtime"
    26  	"k8s.io/klog/v2"
    27  	"k8s.io/kubernetes/pkg/scheduler/apis/config"
    28  	"k8s.io/kubernetes/pkg/scheduler/apis/config/scheme"
    29  	configv1 "k8s.io/kubernetes/pkg/scheduler/apis/config/v1"
    30  )
    31  
    32  // LoadConfigFromFile loads scheduler config from the specified file path
    33  func LoadConfigFromFile(logger klog.Logger, file string) (*config.KubeSchedulerConfiguration, error) {
    34  	data, err := os.ReadFile(file)
    35  	if err != nil {
    36  		return nil, err
    37  	}
    38  
    39  	return loadConfig(logger, data)
    40  }
    41  
    42  func loadConfig(logger klog.Logger, data []byte) (*config.KubeSchedulerConfiguration, error) {
    43  	// The UniversalDecoder runs defaulting and returns the internal type by default.
    44  	obj, gvk, err := scheme.Codecs.UniversalDecoder().Decode(data, nil, nil)
    45  	if err != nil {
    46  		return nil, err
    47  	}
    48  	if cfgObj, ok := obj.(*config.KubeSchedulerConfiguration); ok {
    49  		// We don't set this field in pkg/scheduler/apis/config/{version}/conversion.go
    50  		// because the field will be cleared later by API machinery during
    51  		// conversion. See KubeSchedulerConfiguration internal type definition for
    52  		// more details.
    53  		cfgObj.TypeMeta.APIVersion = gvk.GroupVersion().String()
    54  		return cfgObj, nil
    55  	}
    56  	return nil, fmt.Errorf("couldn't decode as KubeSchedulerConfiguration, got %s: ", gvk)
    57  }
    58  
    59  func encodeConfig(cfg *config.KubeSchedulerConfiguration) (*bytes.Buffer, error) {
    60  	buf := new(bytes.Buffer)
    61  	const mediaType = runtime.ContentTypeYAML
    62  	info, ok := runtime.SerializerInfoForMediaType(scheme.Codecs.SupportedMediaTypes(), mediaType)
    63  	if !ok {
    64  		return buf, fmt.Errorf("unable to locate encoder -- %q is not a supported media type", mediaType)
    65  	}
    66  
    67  	var encoder runtime.Encoder
    68  	switch cfg.TypeMeta.APIVersion {
    69  	case configv1.SchemeGroupVersion.String():
    70  		encoder = scheme.Codecs.EncoderForVersion(info.Serializer, configv1.SchemeGroupVersion)
    71  	default:
    72  		encoder = scheme.Codecs.EncoderForVersion(info.Serializer, configv1.SchemeGroupVersion)
    73  	}
    74  	if err := encoder.Encode(cfg, buf); err != nil {
    75  		return buf, err
    76  	}
    77  	return buf, nil
    78  }
    79  
    80  // LogOrWriteConfig logs the completed component config and writes it into the given file name as YAML, if either is enabled
    81  func LogOrWriteConfig(logger klog.Logger, fileName string, cfg *config.KubeSchedulerConfiguration, completedProfiles []config.KubeSchedulerProfile) error {
    82  	loggerV := logger.V(2)
    83  	if !loggerV.Enabled() && len(fileName) == 0 {
    84  		return nil
    85  	}
    86  	cfg.Profiles = completedProfiles
    87  
    88  	buf, err := encodeConfig(cfg)
    89  	if err != nil {
    90  		return err
    91  	}
    92  
    93  	if loggerV.Enabled() {
    94  		loggerV.Info("Using component config", "config", buf.String())
    95  	}
    96  
    97  	if len(fileName) > 0 {
    98  		configFile, err := os.Create(fileName)
    99  		if err != nil {
   100  			return err
   101  		}
   102  		defer configFile.Close()
   103  		if _, err := io.Copy(configFile, buf); err != nil {
   104  			return err
   105  		}
   106  		logger.Info("Wrote configuration", "file", fileName)
   107  		os.Exit(0)
   108  	}
   109  	return nil
   110  }