GoEmbedFS

GoEmbedFS is a very simple command line utility that generates Go language code with embedded static files.

Features of generated files:

compatibility with http.FileSystem
helper functions for accessing and reading files
embedded files deduplication
gzip support with configurable minimal space savings
go vet and golint clean

Installation

Make sure that you have installed Go binary.

$ go get -u resenje.org/goembedfs/...

Executable goembedfs binary should be in your $GOPATH/bin directory.

Usage

goembedfs [options...] package_name file...

Arguments package_name and file are required. You can provide multiple arguments for file and if file is a directory, all files will be added recursively.

Available options are:

-o to specify output filename. By default the output will be printed to STDOUT.
-w to change the working directory before the file is generated.
--tags a comma-delimited list of build tags.

goembedfs mypackage index.html img.png robots.txt > mypackage.go

All files from a directory

In this case all files from assets directory are embedded.

goembedfs mypackage assets > mypackage.go

Output filename

When STDOUT redirect is not available, like in //go:generate, you can use output filename option.

goembedfs -o mypackage.go mypackage index.html img.png robots.txt

Working directory

It is common to keep all file assets in a specific directly of your project and not to have its name in the generated file. That can be accomplished with -w option.

goembedfs -o mypackage.go -w assets .

All file paths in mypackage.go will not contain assets prefix in path names.

Build tags

To exclude generated files for some type of build, --tags option is available. It can contain a comma delimited list of tags for each line of // +build directive.

Gzip

Generated data may be gzip compressed with option --gzip and to specify minimal space savings (reduction in size relative to the uncompressed size in percentage) for data to be saved as gzip with option --min-gzip-space-savings.

Default minimal space savings is 5%.

goembedfs -o mypackage.go --gzip

To set minimal space savings to 30%:

goembedfs -o mypackage.go --gzip --min-gzip-space-savings 30

It is possible that compressed data is slightly longer then the uncompressed due to gzip metadata. In this case data for that file will be saved in uncompressed form.

Inspiration

There is a number of similar project already available and that are used as inspiration and examples for building this simple alternative. Most notable of them are https://github.com/jteeuwen/go-bindata and https://github.com/benbjohnson/genesis.