embed

Embed static files into go binaries

Takes a list for file or folders (likely at go generate time) and generates Go code that statically implements the a http.FileSystem.

Features:

embed:

• outputs gofmted and linted Go code.
• produces go-gettable go and go assembly sources with go generate.
• keeps data and strings in read-only section of the binary.
• minify HTML, CSS, and JavaScript files.
• compress compressible files with gzip.
• provides http.FileSystem API.
• provides http.Handler handler (if requested),
• generates a test code.
• allows access to compressed data.
• serving gzip files to clients that accept compressed content.
• calculate checksums for serving Etag-based conditional requests.
• zero dependencies on packages outside the standard library (if requested),

The minifier used is github.com/tdewolff/minify.

Source file/folder specification

The source paramaters are a list of folder and/or files, with an optional marker for prefix start. The prefix marker is <->, if you specify a path of ./files/html<->/embed it will import everything under the folder ./files/html/embed as /embed/... for example ./files/html/embed/index.html will be stored as /embed/index.html. There is no limit to the number you can specify but the resultant file system must be unique, if the processing produces two files in the same location embed will error out.

Usage as Binary

Installation

First, get the command-line tool:

go get github.com/inabyte/embed/cmd/embed 

Usage

embed [flags] [files...]

Flags Are:

-o="embed"
  Output files base name.
-pkg=""
  Package name defauls to directory of output.
-tags=""
  Build tags added to output files.
-ignore=""
  Regexp for files we should ignore (for example \\\\.DS_Store).
-include=""
  Regexp for files to include. Only files that match will be included.
-minify="application/javascript,text/javascript,text/css,text/html,text/html; charset=utf-8"
  Comma list of mimetypes to minify.
-modifytime=""
  Unix timestamp to override as modification time for all files.
-no-compress
  If set, do not compress files.
-go
  If set, write only go files
-fileserver
  If set, produce http server code
-binary
  If set, produce self-contained extractor/http server binary (-o will become the binary name)
-noremote
  If set, force zero dependencies on packages outside the standard library.
-nolocalfs
  If set, do not store local file system paths.

Example

Embedded assets can be served with HTTP using the http.Server. Assuming a directory structure similar to below:

.
├── main.go
└── html
    ├── css
    │   └── style.css
    ├── scripts
    │   └── utils.js
    └── index.html

Where main.go contains:

package main

import (
  "log"
  "net/http"
)

func main() {
  // FileHandler() is created by embed and returns a http.Handler.
  log.Fatal(http.ListenAndServe(":8080", FileHandler()))
}

1. Generate the embedded data: embed -o static -pkg=main html
2. Start the server: go run .
3. Access http://localhost:8080/ to view the content.

You can see a worked example in examples/binary dir just run it as go run ./examples/binary

Usage with Import

Config

// Config contains all information needed to run embed.
type Config struct {
	// Output is the file to write output.
	Output string
	// Package name for the generated file.
	Package string
	// Ignore is the regexp for files we should ignore (for example `\.DS_Store`).
	Ignore string
	// Include is the regexp for files to include. If provided, only files that
	// match will be included.
	Include string
	// Minify is comma separated list of mime type to minify.
	Minify string
	// ModifyTime is the Unix timestamp to override as modification time for all files.
	ModifyTime string
	// DisableCompression, if true, does not compress files.
	DisableCompression bool
	// Binary, if true, produce self-contained extractor/http server binary.
	Binary bool
	// NoRemote, if true, zero dependencies on packages outside the standard library.
	NoRemote bool
	// Go, if true, creates only go files.
	Go bool
	// NoLocalFS, if true, do not store local file system paths.
	NoLocalFS bool
	// FileServer, if true, add http.Handler to serve files.
	FileServer bool
	// BuildTags, if set, adds a build tags entry to file.
	BuildTags string
	// Files is the list of files or directories to embed.
	Files []string
}

Example

Embedded assets can be served with HTTP using the http.Server. Assuming a directory structure similar to below:

.
├── main.go
└── html
    ├── css
    │   └── style.css
    ├── scripts
    │   └── utils.js
    └── index.html

Where main.go contains:

package main

import (
  "log"
  "net/http"
)

func main() {
  // FileHandler() is created by embed and returns a http.Handler.
  log.Fatal(http.ListenAndServe(":8080", FileHandler()))
}

And embed_static.go contains:

// +build ignore
package main

import (
  "github.com/inabyte/embed"
)

func main() {
  config := embed.New()

  config.Output = "static"
  config.Package = "main"
  config.Files = []string{"html"}
  config.FileServer = true
  config.NoLocalFS = true

  config.Generate()
}

1. Generate the embedded data: go run embed_static.go
2. Start the server: go run .
3. Access http://localhost:8080/ to view the content.

You can see a worked example in examples/code dir just run it as go run ./examples/code