embed.go.tmpl

// Code generated by openapi-embed. DO NOT EDIT.

package {{.PackageName}}

import (
	"embed"
	"io/fs"
)

//go:embed {{.Filename}}
var {{.Embed}} embed.FS

var {{.EmbedFilename}} = `{{.Filename}}`

func {{.EmbedFile}}() (fs.File, error) {
	return {{.Embed}}.Open({{.EmbedFilename}})
}

main.go

// openapi-embed is used in conjunction with protoc-gen-openapiv2 (see
// https://github.com/grpc-ecosystem/grpc-gateway/) to embed the openapi files
// in the source. This allows services serving grpc-gateway to embed the OpenAPI
// definitions without having to generate those manually.
package main

import (
	"bytes"
	_ "embed"
	"flag"
	"fmt"
	"io"
	"io/fs"
	"log"
	"os"
	"path/filepath"
	"strings"
	"text/template"
)

//go:embed embed.go.tmpl
var tf string

var (
	dir  *string
	sfx  = ".swagger.json"
	tmpl = template.Must(template.New("embedfile").Parse(tf))
)

func main() {
	if err := filepath.Walk(*dir, func(path string, info fs.FileInfo, err error) error {
		if info.IsDir() || !strings.HasSuffix(info.Name(), sfx) {
			return nil
		}

		sf := SwaggerFile{Path: path}
		return generate(sf)
	}); err != nil {
		log.Fatalln(err)
	}
}

func generate(sf SwaggerFile) error {
	var buf bytes.Buffer
	if err := tmpl.Execute(&buf, sf); err != nil {
		return err
	}

	f, err := os.Create(sf.GenPathname())
	if err != nil {
		return err
	}
	if _, err := io.Copy(f, &buf); err != nil {
		return err
	}

	return nil
}

// SwaggerFile is a struct containing the data about the swaggerfile.
type SwaggerFile struct {
	Path string
}

// ProtoFilename returns the proto filename (inferred from the name of the
// swaggerfile).
func (f SwaggerFile) ProtoFilename() string {
	bn := filepath.Base(f.Path)
	return strings.TrimSuffix(bn, sfx)
}

// CamelProtoFilename returns the proto filename (inferred from the name of the
// swaggerfile) in CamelCase.
func (f SwaggerFile) CamelProtoFilename() string {
	fn := f.ProtoFilename()
	fn = strings.ReplaceAll(fn, "_", " ")
	fn = strings.Title(fn)
	return strings.ReplaceAll(fn, " ", "")
}

// Embed returns the name of the embed.FS for the swaggerfile, in the form
// MyServiceSwaggerEmbed.
func (f SwaggerFile) Embed() string {
	fn := f.CamelProtoFilename()
	return fmt.Sprintf("%sSwaggerEmbed", fn)
}

// EmbedFilename generates CamelProtoFilename suffixed by SwaggerFilename, for
// use as an exported variable containing the filename of the swaggerfile (see
// Filename)
func (f SwaggerFile) EmbedFilename() string {
	fn := f.CamelProtoFilename()
	return fmt.Sprintf("%sSwaggerFilename", fn)
}

// EmbedFile generates CamelProtoFilename suffixed by SwaggerFile, for use as
// a function name, eg MyServiceSwaggerFile().
func (f SwaggerFile) EmbedFile() string {
	fn := f.CamelProtoFilename()
	return fmt.Sprintf("%sSwaggerFile", fn)
}

// Filename returns the basename of the swaggerfile.
func (f SwaggerFile) Filename() string {
	return filepath.Base(f.Path)
}

// Dir returns the directory of the swaggerfile.
func (f SwaggerFile) Dir() string {
	return filepath.Dir(f.Path)
}

// PackageName returns the package name.
func (f SwaggerFile) PackageName() string {
	d := filepath.Dir(f.Path)
	return filepath.Base(d)
}

// GenFilename returns the name of the generated file.
func (f SwaggerFile) GenFilename() string {
	return fmt.Sprintf("%s.swaggerembed.go", f.ProtoFilename())
}

// GenPathname returns the pathname of the generated file
func (f SwaggerFile) GenPathname() string {
	return filepath.Join(f.Dir(), f.GenFilename())
}

func init() {
	dir = flag.String("dir", ".", "Directory to search for openapi files")
	flag.Parse()
}