github.com/blixtra/rkt@v0.8.1-0.20160204105720-ab0d1add1a43/rkt/config/stage1.go (about)

     1  // Copyright 2016 The rkt 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 config
    16  
    17  import (
    18  	"encoding/json"
    19  	"fmt"
    20  	"net/url"
    21  	"path/filepath"
    22  	"sort"
    23  	"strings"
    24  )
    25  
    26  type stage1V1JsonParser struct{}
    27  
    28  type stage1V1 struct {
    29  	Name     string `json:"name"`
    30  	Version  string `json:"version"`
    31  	Location string `json:"location"`
    32  }
    33  
    34  var (
    35  	allowedSchemes = map[string]struct{}{
    36  		"file":   struct{}{},
    37  		"docker": struct{}{},
    38  		"http":   struct{}{},
    39  		"https":  struct{}{},
    40  	}
    41  )
    42  
    43  func init() {
    44  	addParser("stage1", "v1", &stage1V1JsonParser{})
    45  	registerSubDir("stage1.d", []string{"stage1"})
    46  }
    47  
    48  func (p *stage1V1JsonParser) parse(config *Config, raw []byte) error {
    49  	var stage1 stage1V1
    50  	if err := json.Unmarshal(raw, &stage1); err != nil {
    51  		return err
    52  	}
    53  	if err := p.validateStage1V1(&stage1); err != nil {
    54  		return fmt.Errorf("invalid stage1 configuration: %v", err)
    55  	}
    56  	// At this point either both name and version are specified or
    57  	// neither. The same goes for data in Config.
    58  	if stage1.Name != "" {
    59  		if config.Stage1.Name != "" {
    60  			return fmt.Errorf("name and version of a default stage1 image are already specified")
    61  		}
    62  		config.Stage1.Name = stage1.Name
    63  		config.Stage1.Version = stage1.Version
    64  	}
    65  	if stage1.Location != "" {
    66  		if config.Stage1.Location != "" {
    67  			return fmt.Errorf("location of a default stage1 image is already specified")
    68  		}
    69  		config.Stage1.Location = stage1.Location
    70  	}
    71  	return nil
    72  }
    73  
    74  func (p *stage1V1JsonParser) validateStage1V1(stage1 *stage1V1) error {
    75  	if stage1.Name == "" && stage1.Version != "" {
    76  		return fmt.Errorf("default stage1 image version specified, but name is missing")
    77  	}
    78  	if stage1.Name != "" && stage1.Version == "" {
    79  		return fmt.Errorf("default stage1 image name specified, but version is missing")
    80  	}
    81  	if stage1.Location != "" {
    82  		if !filepath.IsAbs(stage1.Location) {
    83  			url, err := url.Parse(stage1.Location)
    84  			if err != nil {
    85  				return fmt.Errorf("default stage1 image location is an invalid URL: %v", err)
    86  			}
    87  			if url.Scheme == "" {
    88  				return fmt.Errorf("default stage1 image location is either a relative path or a URL without scheme")
    89  			}
    90  			if _, ok := allowedSchemes[url.Scheme]; !ok {
    91  				schemes := toArray(allowedSchemes)
    92  				sort.Strings(schemes)
    93  				return fmt.Errorf("default stage1 image location URL has invalid scheme %q, allowed schemes are %q", url.Scheme, strings.Join(schemes, `", "`))
    94  			}
    95  		}
    96  	}
    97  	return nil
    98  }