github.com/mika/distribution@v2.2.2-0.20160108133430-a75790e3d8e0+incompatible/cmd/registry-api-descriptor-template/main.go (about)

     1  // registry-api-descriptor-template uses the APIDescriptor defined in the
     2  // api/v2 package to execute templates passed to the command line.
     3  //
     4  // For example, to generate a new API specification, one would execute the
     5  // following command from the repo root:
     6  //
     7  // 	$ registry-api-descriptor-template docs/spec/api.md.tmpl > docs/spec/api.md
     8  //
     9  // The templates are passed in the api/v2.APIDescriptor object. Please see the
    10  // package documentation for fields available on that object. The template
    11  // syntax is from Go's standard library text/template package. For information
    12  // on Go's template syntax, please see golang.org/pkg/text/template.
    13  package main
    14  
    15  import (
    16  	"log"
    17  	"net/http"
    18  	"os"
    19  	"path/filepath"
    20  	"regexp"
    21  	"text/template"
    22  
    23  	"github.com/docker/distribution/registry/api/errcode"
    24  	"github.com/docker/distribution/registry/api/v2"
    25  )
    26  
    27  var spaceRegex = regexp.MustCompile(`\n\s*`)
    28  
    29  func main() {
    30  
    31  	if len(os.Args) != 2 {
    32  		log.Fatalln("please specify a template to execute.")
    33  	}
    34  
    35  	path := os.Args[1]
    36  	filename := filepath.Base(path)
    37  
    38  	funcMap := template.FuncMap{
    39  		"removenewlines": func(s string) string {
    40  			return spaceRegex.ReplaceAllString(s, " ")
    41  		},
    42  		"statustext":    http.StatusText,
    43  		"prettygorilla": prettyGorillaMuxPath,
    44  	}
    45  
    46  	tmpl := template.Must(template.New(filename).Funcs(funcMap).ParseFiles(path))
    47  
    48  	data := struct {
    49  		RouteDescriptors []v2.RouteDescriptor
    50  		ErrorDescriptors []errcode.ErrorDescriptor
    51  	}{
    52  		RouteDescriptors: v2.APIDescriptor.RouteDescriptors,
    53  		ErrorDescriptors: append(errcode.GetErrorCodeGroup("registry.api.v2"),
    54  			// The following are part of the specification but provided by errcode default.
    55  			errcode.ErrorCodeUnauthorized.Descriptor(),
    56  			errcode.ErrorCodeDenied.Descriptor(),
    57  			errcode.ErrorCodeUnsupported.Descriptor()),
    58  	}
    59  
    60  	if err := tmpl.Execute(os.Stdout, data); err != nil {
    61  		log.Fatalln(err)
    62  	}
    63  }
    64  
    65  // prettyGorillaMuxPath removes the regular expressions from a gorilla/mux
    66  // route string, making it suitable for documentation.
    67  func prettyGorillaMuxPath(s string) string {
    68  	// Stateful parser that removes regular expressions from gorilla
    69  	// routes. It correctly handles balanced bracket pairs.
    70  
    71  	var output string
    72  	var label string
    73  	var level int
    74  
    75  start:
    76  	if s[0] == '{' {
    77  		s = s[1:]
    78  		level++
    79  		goto capture
    80  	}
    81  
    82  	output += string(s[0])
    83  	s = s[1:]
    84  
    85  	goto end
    86  capture:
    87  	switch s[0] {
    88  	case '{':
    89  		level++
    90  	case '}':
    91  		level--
    92  
    93  		if level == 0 {
    94  			s = s[1:]
    95  			goto label
    96  		}
    97  	case ':':
    98  		s = s[1:]
    99  		goto skip
   100  	default:
   101  		label += string(s[0])
   102  	}
   103  	s = s[1:]
   104  	goto capture
   105  skip:
   106  	switch s[0] {
   107  	case '{':
   108  		level++
   109  	case '}':
   110  		level--
   111  	}
   112  	s = s[1:]
   113  
   114  	if level == 0 {
   115  		goto label
   116  	}
   117  
   118  	goto skip
   119  label:
   120  	if label != "" {
   121  		output += "<" + label + ">"
   122  		label = ""
   123  	}
   124  end:
   125  	if s != "" {
   126  		goto start
   127  	}
   128  
   129  	return output
   130  
   131  }