configfiles.go

Documentation: k8s.io/kubernetes/pkg/kubelet/kubeletconfig/configfiles

     1  /*
     2  Copyright 2017 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 configfiles
    18  
    19  import (
    20  	"fmt"
    21  	"path/filepath"
    22  
    23  	"k8s.io/apimachinery/pkg/runtime/serializer"
    24  	kubeletconfig "k8s.io/kubernetes/pkg/kubelet/apis/config"
    25  	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/config/scheme"
    26  	utilcodec "k8s.io/kubernetes/pkg/kubelet/kubeletconfig/util/codec"
    27  	utilfs "k8s.io/kubernetes/pkg/util/filesystem"
    28  )
    29  
    30  // Loader loads configuration from a storage layer
    31  type Loader interface {
    32  	// Load loads and returns the KubeletConfiguration from the storage layer, or an error if a configuration could not be loaded
    33  	Load() (*kubeletconfig.KubeletConfiguration, error)
    34  	// LoadIntoJSON loads and returns the KubeletConfiguration from the storage layer, or an error if a configuration could not be
    35  	// loaded. It returns the configuration as a JSON byte slice
    36  	LoadIntoJSON() ([]byte, error)
    37  }
    38  
    39  // fsLoader loads configuration from `configDir`
    40  type fsLoader struct {
    41  	// fs is the filesystem where the config files exist; can be mocked for testing
    42  	fs utilfs.Filesystem
    43  	// kubeletCodecs is the scheme used to decode config files
    44  	kubeletCodecs *serializer.CodecFactory
    45  	// kubeletFile is an absolute path to the file containing a serialized KubeletConfiguration
    46  	kubeletFile string
    47  }
    48  
    49  // NewFsLoader returns a Loader that loads a KubeletConfiguration from the `kubeletFile`
    50  func NewFsLoader(fs utilfs.Filesystem, kubeletFile string) (Loader, error) {
    51  	_, kubeletCodecs, err := kubeletscheme.NewSchemeAndCodecs(serializer.EnableStrict)
    52  	if err != nil {
    53  		return nil, err
    54  	}
    55  
    56  	return &fsLoader{
    57  		fs:            fs,
    58  		kubeletCodecs: kubeletCodecs,
    59  		kubeletFile:   kubeletFile,
    60  	}, nil
    61  }
    62  
    63  func (loader *fsLoader) Load() (*kubeletconfig.KubeletConfiguration, error) {
    64  	data, err := loader.fs.ReadFile(loader.kubeletFile)
    65  	if err != nil {
    66  		return nil, fmt.Errorf("failed to read kubelet config file %q, error: %v", loader.kubeletFile, err)
    67  	}
    68  
    69  	// no configuration is an error, some parameters are required
    70  	if len(data) == 0 {
    71  		return nil, fmt.Errorf("kubelet config file %q was empty", loader.kubeletFile)
    72  	}
    73  
    74  	kc, err := utilcodec.DecodeKubeletConfiguration(loader.kubeletCodecs, data)
    75  	if err != nil {
    76  		return nil, err
    77  	}
    78  
    79  	// make all paths absolute
    80  	resolveRelativePaths(kubeletconfig.KubeletConfigurationPathRefs(kc), filepath.Dir(loader.kubeletFile))
    81  	return kc, nil
    82  }
    83  
    84  func (loader *fsLoader) LoadIntoJSON() ([]byte, error) {
    85  	data, err := loader.fs.ReadFile(loader.kubeletFile)
    86  	if err != nil {
    87  		return nil, fmt.Errorf("failed to read drop-in kubelet config file %q, error: %v", loader.kubeletFile, err)
    88  	}
    89  
    90  	// no configuration is an error, some parameters are required
    91  	if len(data) == 0 {
    92  		return nil, fmt.Errorf("kubelet config file %q was empty", loader.kubeletFile)
    93  	}
    94  
    95  	return utilcodec.DecodeKubeletConfigurationIntoJSON(loader.kubeletCodecs, data)
    96  }
    97  
    98  // resolveRelativePaths makes relative paths absolute by resolving them against `root`
    99  func resolveRelativePaths(paths []*string, root string) {
   100  	for _, path := range paths {
   101  		// leave empty paths alone, "no path" is a valid input
   102  		// do not attempt to resolve paths that are already absolute
   103  		if len(*path) > 0 && !utilfs.IsAbs(*path) {
   104  			*path = filepath.Join(root, *path)
   105  		}
   106  	}
   107  }
   108
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