Varnish vs Nginx configuration added

DOCUMENTATION/content/documentation/index.md

@@ -674,6 +674,7 @@ You may wanna change the default security configuration, so go to `http://localh
 
 <br>
 <a name="Use-Redis"></a>
+
 ## Use Redis
 
 1 - First make sure you run the Redis Container (`redis`) with the `docker-compose up` command.
@@ -761,12 +762,81 @@ Read the [Laravel official documentation](https://laravel.com/docs/5.7/redis#con
 ```
 
 
+<br>
+<a name="Use-Varnish"></a>
 
+## Use Varnish
 
+The goal was to proxy request to varnish server using nginx. So only nginx has been configured for Varnish proxy.
+Nginx is on port 80 or 443. Nginx sends request through varnish server and varnish server sends request back to nginx on port 81 (external port is defined in `VARNISH_BACKEND_PORT`). 
 
+The idea was taken from this [post](https://www.linode.com/docs/websites/varnish/use-varnish-and-nginx-to-serve-wordpress-over-ssl-and-http-on-debian-8/) 
+
+The Varnish configuration was developed and tested for Wordpress only. Probably it works with other systems.
+
+#### Steps to configure varnish proxy server:
+1. You have to set domain name for VARNISH_PROXY1_BACKEND_HOST variable.
+2. If you want to use varnish for different domains, you have to add new configuration section in your env file.
+    ``` 
+    VARNISH_PROXY1_CACHE_SIZE=128m
+    VARNISH_PROXY1_BACKEND_HOST=replace_with_your_domain.name
+    VARNISH_PROXY1_SERVER=SERVER1
+    ``` 
+3. Then you have to add new config section into docker-compose.yml with related variables:
+    ```
+    custom_proxy_name:
+          container_name: custom_proxy_name
+          build: ./varnish
+          expose:
+            - ${VARNISH_PORT}
+          environment:
+            - VARNISH_CONFIG=${VARNISH_CONFIG}
+            - CACHE_SIZE=${VARNISH_PROXY2_CACHE_SIZE}
+            - VARNISHD_PARAMS=${VARNISHD_PARAMS}
+            - VARNISH_PORT=${VARNISH_PORT}
+            - BACKEND_HOST=${VARNISH_PROXY2_BACKEND_HOST}
+            - BACKEND_PORT=${VARNISH_BACKEND_PORT}
+            - VARNISH_SERVER=${VARNISH_PROXY2_SERVER}
+          ports:
+            - "${VARNISH_PORT}:${VARNISH_PORT}"
+          links:
+            - workspace
+          networks:
+            - frontend
+    ``` 
+4. change your varnish config and add nginx configuration. Example Nginx configuration is here: `nginx/sites/laravel_varnish.conf.example`.
+5. `varnish/default.vcl` is old varnish configuration, which was used in the previous version. Use `default_wordpress.vcl` instead.
+
+#### How to run:
+1. Rename `default_wordpress.vcl` to `default.vcl`
+2. `docker-compose up -d nginx`
+3. `docker-compose up -d proxy`
+
+Keep in mind that varnish server must be built after Nginx cause varnish checks domain affordability.
+
+#### FAQ:
+
+1. How to purge cache? <br>
+run from any cli: <br>`curl -X PURGE https://yourwebsite.com/`.
+2. How to reload varnish?<br>
+`docker container exec proxy varnishreload`
+3. Which varnish commands are allowed?
+    - varnishadm     
+    - varnishd      
+    - varnishhist    
+    - varnishlog     
+    - varnishncsa    
+    - varnishreload  
+    - varnishstat    
+    - varnishtest    
+    - varnishtop
+4. How to reload Nginx?<br>
+`docker exec Nginx nginx -t`<br>
+`docker exec Nginx nginx -s reload`
 
 <br>
 <a name="Use-Mongo"></a>
+
 ## Use Mongo
 
 1 - First install `mongo` in the Workspace and the PHP-FPM Containers: