Compress

Updated Feb 05, 2023 ·

Overview

Compression is a common way to speed up websites by reducing the size of content before sending it to users.

• Connects middleware to the router
• Compresses responses before sending
• Makes pages load faster and improves performance

Compressing content helps sites load quickly, which users and search engines like.

How Compression Works

When a request hits the router, the compression middleware compresses the response data.

• Router receives the request
• Middleware compresses the response
• Compressed data is sent back to the user

This process saves bandwidth and speeds up loading times.

Enabling Compression

Turning on compression in Traefik is simple with one label.

• Name your middleware (e.g., test-compress)
• Use Traefik’s built-in compress middleware
• Set the compress option to true

Example:

labels:
  - "traefik.http.middlewares.test-compress.compress=true"
  - "traefik.http.routers.myapp.middlewares=test-compress"

Here, test-compress is the user-defined middleware name linked to the router.

Lab: Enable Gzip Compression

This lab shows how to turn on gzip compression to make your app’s content smaller and faster to load.

• Use a special compression config file
• Add compression middleware with one simple label

Clone the Repository

To try out the lab, clone the project repository from GitHub.

• Github repo: joseeden/labs-traefik

Clone and move into the project directory:

git clone https://github.com/joseeden/labs-traefik.git 
cd labs-traefik/05-middleware/02-compress

Project structure:

05-middleware
├── 02-compress
│   ├── .gitignore
│   ├── docker-compose.compress.yml
│   ├── traefik.yml
│   └── usersfile

Creating Passwords

For this lab, we'll use basic authentication, so we need a safe way to store user passwords. Passwords must be hashed before adding them to the users file.

To create hashed passwords, install the tool htpasswd:

sudo apt install -y apache2-utils

Here are example user credentials. You can change them if you want:

Username	Password
johnsmith	Thr3@tl3u3lw!dN!QHt
janedoe	@Ll!$szM3lLiND@h0oD

Generate a hash with this command:

htpasswd -nb johnsmith 'Thr3@tl3u3lw!dN!QHt''

You should see output like:

johnsmith:$apr1$cipim6NJ$LK11Xtf0t92UvxjKCV8ii0

Do the same for each user.

Next, create a file named usersfile in the same folder as your Docker compose file. Put all hashed credentials here, one user per line:

johnsmith:$apr1$cipim6NJ$LK11Xtf0t92UvxjKCV8ii0
janedoe:$apr1$t65c7tuF$Qscp40RYl.Tq02pUnSv5r1

Add usersfile to your .gitignore file to keep it out of version control:

.gitignore

usersfile

This usersfile will be used in the Docker compose setup next.

Prepare the Files

The compression setup is straightforward in the docker-compose.compress.yml file.

version: "3"

services:
  traefik:
    image: traefik:v2.3
    ports:
      - "80:80"
      - "443:443"
      - "8080:8080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ./traefik.yml:/etc/traefik/traefik.yml
      - ./usersfile:/usersfile:ro # <-- mount your users file here

  catapp:
    image: mikesir87/cats:1.0
    labels:
      - "traefik.enable=true"
      # Routers
      - "traefik.http.routers.catapp.rule=Host(`catapp.localhost`)"
      - "traefik.http.routers.catapp.service=catapp"
      - "traefik.http.routers.catapp.entrypoints=web"
      - "traefik.http.routers.catapp.middlewares=test-auth,test-compress"
      # Services
      - "traefik.http.services.catapp.loadbalancer.server.port=5000"
      # Middleware BasicAuth using usersfile
      - "traefik.http.middlewares.test-auth.basicauth.usersfile=/usersfile"
      # Compress Middleware
      - "traefik.http.middlewares.test-compress.compress=true"

This enables compression alongside other middlewares like basic auth.

info

This lab uses the same usersfile and traefik.yml as the ones in the Basic Auth lab.

Deploying the Compression

If you did the previous labs, make sure to delete them first:

docker stack rm traefik

Deploy the Docker compose file for this lab.

docker stack deploy -c docker-compose.compress.yml traefik

Testing

Access the dashboard and go to Routers > Click catapp@docker.

http://localhost:8080/dashboard/#/ 

You should see the two middlewares ("compress" and "basicauth") attached to this router

What to expect: Once enabled, gzip compresses the response before it reaches the user. This saves bandwidth and should make pages load faster, especially if the content includes large images or files.

To test, access the catapp application on your browser and referesh it a couple of times. In theory, it should load much faster.

Cleanup

Delete the deployed stack:

docker stack rm traefik 

You can also delete the usersfile:

rm -f usersfile