Update README.md

Author: guillaumebriday

README.md

@@ -1,5 +1,4 @@
 [![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.me/guillaumebriday)
-[![Docker Automated build](https://img.shields.io/docker/automated/guillaumebriday/traefik-custom-error-pages.svg)](https://hub.docker.com/r/guillaumebriday/traefik-custom-error-pages/)
 [![Docker Pulls](https://img.shields.io/docker/pulls/guillaumebriday/traefik-custom-error-pages.svg)](https://hub.docker.com/r/guillaumebriday/traefik-custom-error-pages/)
 [![Docker Stars](https://img.shields.io/docker/stars/guillaumebriday/traefik-custom-error-pages.svg)](https://hub.docker.com/r/guillaumebriday/traefik-custom-error-pages/)
 [![Netlify Status](https://api.netlify.com/api/v1/badges/64de9cea-fa16-4f76-b5b8-a1abb5eb4e2f/deploy-status)](https://app.netlify.com/sites/traefik-custom-error-pages/deploys)
@@ -10,29 +9,22 @@ A bunch of custom error pages for Traefik built with [Jekyll](https://jekyllrb.c
 
 ## Installation
 
+Install dependencies
 ```bash
 $ bundle install
 ```
 
-## Development
-
-The current folder will be generated into ./_site :
+If you want to build the project on your host:
 ```bash
 $ jekyll build
 ```
 
-Build the site on the preview server :
+If you want to preview the pages before building the Docker image :
 ```bash
 $ jekyll serve
 $ open http://127.0.0.1:4000/
 ```
 
-## Production
-
-You can use this project in production with Netlify:
-
-[![Deploy to Netlify](https://www.netlify.com/img/deploy/button.svg)](https://app.netlify.com/start/deploy?repository=https://github.com/guillaumebriday/traefik-custom-error-pages)
-
 ## How to use with Traefik and Docker
 
 Labels are already define in the image to work with Traefik.
@@ -43,6 +35,28 @@ To use it in production just run the container :
 $ docker run -d --restart always guillaumebriday/traefik-custom-error-pages
 ```
 
+## Build the image
+
+This is a [multi-stage build](https://docs.docker.com/develop/develop-images/multistage-build/), to build the final image:
+```bash
+$ docker build -f .cloud/docker/Dockerfile -t traefik-custom-error-pages .
+```
+
+## How it works?
+
+As you can see in the Dockerfile, I use [Nginx](https://www.nginx.com/) as Web server to serve static files. To generate this pages, I use [Jekyll](https://jekyllrb.com/) in the first step of the build.
+
+For traefik, I hardcoded [Labels](https://docs.traefik.io/user-guide/docker-and-lets-encrypt/#labels) in the Dockerfile.
+
+You will find in this article [https://www.techjunktrunk.com/docker/2017/11/03/traefik-default-server-catch-all](https://www.techjunktrunk.com/docker/2017/11/03/traefik-default-server-catch-all/] why I set up `priority` and `rule` this way.
+
+```ini
+LABEL traefik.frontend.priority="1"
+LABEL traefik.frontend.rule="HostRegexp:{catchall:.*}"
+```
+
+It's very useful because this container will respond to all requests only if there is no container with a real rule.
+
 ## Credits
 
 I used the [Laravel](https://laravel.com/) default HTTP error pages.