Go 1.16 has file embedding built-in, you should use that!
Staticfiles allows you to embed a directory of files into your Go binary. It is optimized for performance and file size, and automatically compresses everything before embedding it. Here are some of its features:
- Compresses files, to make sure the resulting binary isn't bloated. It only compresses files that are actually smaller when
gzip
ped. - Serves files
gzip
ped (while still allowing clients that don't support it to be served). - Ignores hidden files (anything that starts with
.
). - Fast. The command-line tool reads and compresses files in parallel, and the resulting Go file serves files very quickly, avoiding unnecessary allocations.
- No built-in development mode, but makes it very easy to implement one (see local development mode).
It has some clever tricks, like only compressing a file if it actually makes the binary smaller (PNG files won't be compressed, as they already are and compressing them again will make them bigger).
I recommend creating a separate package inside your project to serve as the container for the embedded files.
For an example of how to use the resulting package, check out example/example.go
. You can also see the API it generates at godoc.org.
Install with
go get bou.ke/staticfiles
Simply run the following command (it will create the result directory if it doesn't exist yet):
staticfiles -o files/files.go static/
I recommend putting it into a Makefile
as follows:
files/files.go: static/*
staticfiles -o files/files.go static/
The staticfiles
command accept the following arguments:
--build-tags string
Build tags to write to the file
-o string
File to write results to. (default "staticfiles.go")
--package string
Package name of the resulting file. Defaults to name of the resulting file directory
While Staticfiles doesn't have a built-in local development mode, it does support build tags which makes implementing one very easy. Simply run staticfiles
with --build-tags="!dev"
and add a file in the same directory that implements the same API, but with //+build dev
at the that and using http.FileServer
under the hood. You can find an example in files/files_dev.go
. Once you have that set up you can simply do go build --tags="dev"
to compile the development version. In the way I set it up, you could even do go build --tags="dev" -ldflags="-X bou.ke/staticfiles/files.staticDir=$(pwd)/static"
to set the static file directory to a specific path.
The resulting file will contain the following functions and variables:
ServeHTTP
will attempt to serve an embedded file, responding with gzip compression if the clients supports it and the embedded file is compressed.
Open
allows you to read an embedded file directly. It will return a decompressing Reader
if the file is embedded in compressed format. You should close the Reader
after you're done with it.
ModTime
returns the modification time of the original file. This can be useful for caching purposes.
NotFound
is used to respond to a request when no file was found that matches the request. It defaults to http.NotFound
, but can be overwritten.
Server
is simply ServeHTTP
but wrapped in http.HandlerFunc
so it can be passed into net/http
functions directly.