github.com/theishshah/operator-sdk@v0.6.0/pkg/helm/watches/watches.go (about)

     1  // Copyright 2019 The Operator-SDK Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package watches
    16  
    17  import (
    18  	"errors"
    19  	"fmt"
    20  	"io/ioutil"
    21  
    22  	yaml "gopkg.in/yaml.v2"
    23  	"k8s.io/apimachinery/pkg/runtime/schema"
    24  	"k8s.io/helm/pkg/chartutil"
    25  )
    26  
    27  // Watch defines options for configuring a watch for a Helm-based
    28  // custom resource.
    29  type Watch struct {
    30  	GroupVersionKind        schema.GroupVersionKind
    31  	ChartDir                string
    32  	WatchDependentResources bool
    33  }
    34  
    35  type yamlWatch struct {
    36  	Group                   string `yaml:"group"`
    37  	Version                 string `yaml:"version"`
    38  	Kind                    string `yaml:"kind"`
    39  	Chart                   string `yaml:"chart"`
    40  	WatchDependentResources bool   `yaml:"watchDependentResources"`
    41  }
    42  
    43  func (w *yamlWatch) UnmarshalYAML(unmarshal func(interface{}) error) error {
    44  	// by default, the operator will watch dependent resources
    45  	w.WatchDependentResources = true
    46  
    47  	// hide watch data in plain struct to prevent unmarshal from calling
    48  	// UnmarshalYAML again
    49  	type plain yamlWatch
    50  
    51  	return unmarshal((*plain)(w))
    52  }
    53  
    54  // Load loads a slice of Watches from the watch file at `path`. For each entry
    55  // in the watches file, it verifies the configuration. If an error is
    56  // encountered loading the file or verifying the configuration, it will be
    57  // returned.
    58  func Load(path string) ([]Watch, error) {
    59  	b, err := ioutil.ReadFile(path)
    60  	if err != nil {
    61  		return nil, err
    62  	}
    63  
    64  	yamlWatches := []yamlWatch{}
    65  	err = yaml.Unmarshal(b, &yamlWatches)
    66  	if err != nil {
    67  		return nil, err
    68  	}
    69  
    70  	watches := []Watch{}
    71  	watchesMap := make(map[schema.GroupVersionKind]Watch)
    72  	for _, w := range yamlWatches {
    73  		gvk := schema.GroupVersionKind{
    74  			Group:   w.Group,
    75  			Version: w.Version,
    76  			Kind:    w.Kind,
    77  		}
    78  
    79  		if err := verifyGVK(gvk); err != nil {
    80  			return nil, fmt.Errorf("invalid GVK: %s: %s", gvk, err)
    81  		}
    82  
    83  		if _, err := chartutil.IsChartDir(w.Chart); err != nil {
    84  			return nil, fmt.Errorf("invalid chart directory %s: %s", w.Chart, err)
    85  		}
    86  
    87  		if _, ok := watchesMap[gvk]; ok {
    88  			return nil, fmt.Errorf("duplicate GVK: %s", gvk)
    89  		}
    90  		watch := Watch{
    91  			GroupVersionKind:        gvk,
    92  			ChartDir:                w.Chart,
    93  			WatchDependentResources: w.WatchDependentResources,
    94  		}
    95  		watchesMap[gvk] = watch
    96  		watches = append(watches, watch)
    97  	}
    98  	return watches, nil
    99  }
   100  
   101  func verifyGVK(gvk schema.GroupVersionKind) error {
   102  	// A GVK without a group is valid. Certain scenarios may cause a GVK
   103  	// without a group to fail in other ways later in the initialization
   104  	// process.
   105  	if gvk.Version == "" {
   106  		return errors.New("version must not be empty")
   107  	}
   108  	if gvk.Kind == "" {
   109  		return errors.New("kind must not be empty")
   110  	}
   111  	return nil
   112  }