Compress CSS and JS with gzip before serving to reduce load time/page…

… weight (#25658)

For #24732.

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [x] A detailed QA plan exists on the associated ticket (if it isn't
there, work with the product group's QA engineer to add it)
- [x] Manual QA for all new/changed functionality

changes/24732-gzip

@@ -0,0 +1 @@
+* Added gzip compression for static CSS and JS assets to decrease bundle download times

go.mod

@@ -158,6 +158,7 @@ require (
 	github.com/Masterminds/semver/v3 v3.1.1 // indirect
 	github.com/Masterminds/sprig v2.22.0+incompatible // indirect
 	github.com/Microsoft/go-winio v0.6.2 // indirect
+	github.com/NYTimes/gziphandler v1.1.1 // indirect
 	github.com/OneOfOne/xxhash v1.2.8 // indirect
 	github.com/ProtonMail/go-crypto v1.1.3 // indirect
 	github.com/agnivade/levenshtein v1.1.1 // indirect

go.sum

@@ -62,6 +62,8 @@ github.com/Microsoft/go-winio v0.4.15/go.mod h1:tTuCMEN+UleMWgg9dVx4Hu52b1bJo+59
 github.com/Microsoft/go-winio v0.5.2/go.mod h1:WpS1mjBmmwHBEWmogvA2mj8546UReBk4v8QkMxJ6pZY=
 github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
+github.com/NYTimes/gziphandler v1.1.1 h1:ZUDjpQae29j0ryrS0u/B8HZfJBtBQHjqw2rQ2cqUQ3I=
+github.com/NYTimes/gziphandler v1.1.1/go.mod h1:n/CVRwUEOgIxrgPvAQhUUr9oeUtvrhMomdKFjzJNB0c=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/OneOfOne/xxhash v1.2.8 h1:31czK/TI9sNkxIKfaUfGlU47BAxQ0ztGgd9vPyqimf8=
 github.com/OneOfOne/xxhash v1.2.8/go.mod h1:eZbhyaAYD41SGSSsnmcpxVoRiQ/MPUTjUdIIOT9Um7Q=

server/service/frontend.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/url"
 
+	"github.com/NYTimes/gziphandler"
 	assetfs "github.com/elazarl/go-bindata-assetfs"
 	"github.com/fleetdm/fleet/v4/server/bindata"
 	"github.com/fleetdm/fleet/v4/server/fleet"
@@ -145,5 +146,13 @@ func generateEnrollOTAURL(fleetURL string, enrollSecret string) (string, error)
 }
 
 func ServeStaticAssets(path string) http.Handler {
-	return http.StripPrefix(path, http.FileServer(newBinaryFileSystem("/assets")))
+	contentTypes := []string{"text/javascript", "text/css"}
+	withoutGzip := http.StripPrefix(path, http.FileServer(newBinaryFileSystem("/assets")))
+
+	withOpts, err := gziphandler.GzipHandlerWithOpts(gziphandler.ContentTypes(contentTypes))
+	if err != nil { // fall back to serving without gzip if serving with gzip somehow fails
+		return withoutGzip
+	}
+
+	return withOpts(withoutGzip)
 }