By enabling compression in Envoy you can save some network bandwidth, at the expense of increased processor usage.

Envoy supports compression and decompression for both requests and responses.

This sandbox provides an example of response compression served over HTTP. Although HTTPS is not demonstrated, compression can be used for this also.

The sandbox covers two scenarios:

  • compression of files from an upstream server

  • compression of Envoy’s own statistics

Step 1: Start all of our containers

Change to the examples/gzip directory and bring up the docker composition.

$ pwd
$ docker-compose pull
$ docker-compose up --build -d
$ docker-compose ps
Name                 Command                        State   Ports
gzip_envoy-stats_1   /docker-entrypoint.sh /usr ... Up>10000/tcp,:::10000->10000/tcp,>9901/tcp,:::9901->9901/tcp,>9902/tcp,:::9902->9902/tcp
gzip_service_1       python3 /code/service.py       Up

Step 2: Test Envoy’s compression of upstream files

The sandbox is configured with two endpoints on port 10000 for serving upstream files:

  • /file.txt

  • /file.json

Only /file.json is configured to be compressed.

Use curl to check that the response from requesting file.json contains the content-encoding: gzip header.

You will need to add an accept-encoding: gzip request header.

$ curl -si -H "Accept-Encoding: gzip" localhost:10000/file.json | grep "content-encoding"
content-encoding: gzip

As only files with a content-type of application/json are configured to be gzipped, the response from requesting file.txt should not contain the content-encoding: gzip header, and the file will not be compressed:

$ curl -si -H "Accept-Encoding: gzip" localhost:10000/file.txt | grep "content-encoding"

Step 3: Test compression of Envoy’s statistics

The sandbox is configured with two ports serving Envoy’s admin and statistics interface:

  • 9901 exposes the standard admin interface

  • 9902 exposes a compressed version of the admin interface

Use curl to make a request for uncompressed statistics on port 9901, it should not contain the content-encoding header in the response:

$ curl -si -H "Accept-Encoding: gzip" localhost:9901/stats/prometheus | grep "content-encoding"

Now, use curl to make a request for the compressed statistics:

$ curl -si -H "Accept-Encoding: gzip" localhost:9902/stats/prometheus | grep "content-encoding"
content-encoding: gzip

See also

Gzip API

API and configuration reference for Envoy’s gzip compression.

Compression configuration

Reference documentation for Envoy’s compressor filter.

Envoy admin quick start guide

Quick start guide to the Envoy admin interface.