# | Introduction to docker (2) |


[TOC]

## II. Linking containers

### 1)





## III. Setting up a development stack



### 1) Choosing images



We will setup a simple web dev stack with :

- nginx (_i.e. nginx:latest_)
- mariadb (_i.e. mariadb:latest_)
- php-fpm (_i.e. php:7-fpm_)



### 2) Volume & network sharing policy



#### 1. Volume sharing



###### 	a) Configuration files

The **apache** and **php** configuration will be on the host machine (for easy modification) and only mounted on the containers to override the default configuration files. A [virtual](./virtual) folder will hold these configurations with the same path for consistency:
- the nginx configuration file is located at [virtual/etc/nginx/nginx.conf](./virtual/etc/nginx/nginx.conf).
- the php-fpm configuration file is located at [virtual/usr/local/etc/php-fpm.d/www.conf](./virtual/usr/local/etc/php-fpm.d/www.conf).



###### 	b) Storage files

MariaDB will have its whole data folder (_i.e. `/var/lib/mysql`_) on the host in the _virtual_ folder to have the data remaining throughout containers. This property makes the database consistent and persistent among container creation/deletion.



###### 	c) Log files

Also logs will be mounted the same way in order for developers to easily check these out when needed (_e.g. `virtual/var/log/apache2/access.log`_). Also, note that even if the container is removed, the logs will remain.

######  d) Development folder

The development folder (_i.e. the actual code to test_) is located in the folder [virtual/vhost](./virtual/vhost). In a real-world use of this configuration, I would clone a git repository into it in order for my docker configuration and my actual code not to mix together ; we could then use _git submodules_ for version stability among the 2 repositories.




#### 2. Network sharing

The whole system will only expose its port `8080` ; we are not using the default HTTP port not to break a possible web server on the host. Containers between them will be connected through the default overlay network which is unreachable from the host.