Moving Go application to cloud VM: Gzip Middleware

Recently I was working on an ArozOS update and someone suggested that he want to deploy ArozOS (which is a web desktop platform) to a cloud VM and he needs to minimize the bandwidth used in serving media and web template files.

How Gzip Middleware Works

After some research, I decided to add a layer of "gzip middleware" in between the mux / router and the response writer layer. If you try to illustrate the new layer in a diagram, it will looks like this

Implementation

After knowing what I need, I wrote an implementation of it using Go Module architecture. The following is the full code extracted from my ArozOS project gzip middleware module.

See the whole system implementation here

To use it, simpliy call it with your standard http.HandleFunc and http.Handle as follows

if *enable_gzip {
    http.HandleFunc("/media/", gzipmiddleware.CompressFunc(serverMedia))
}else{
    http.HandleFunc("/media/", serverMedia)
}

fs := http.FileServer(http.Dir("./web"))
if *enable_gzip {
    //Gzip enabled. Always serve with gzip if header exists
    http.Handle("/", gzipmiddleware.Compress(fs))
} else {
    //Normal file server without gzip
    http.Handle("/", fs)
}

Results

The following is the compression results of the ArozOS desktop template. You can see the gzip middleware helps to save a around 160KB per request. If you are running it on a cloud server, this might save you a few bucks in long run.

(Top: With gzip middleware enabled; Bottom: With gzip middleware disabled)

Well, basically that is it. Hope you find it useful :)