Merge branch 'hackel-change-mysql-version'

* hackel-change-mysql-version:
  Add documentation on the MYSQL_VERSION variable.
  Allow specifying the version of MySQL to install in .env file.

DOCUMENTATION/content/documentation/index.md

@@ -158,8 +158,7 @@ You might use the `--no-cache` option if you want full rebuilding (`docker-compo
 
 ## Speed up with docker-sync
 
-Docker for Mac is [slow](https://github.com/docker/for-mac/issues/77) due to poor performance when the application accesses files shared with the host machine. 
+Docker on the Mac [is slow](https://github.com/docker/for-mac/issues/77), at the time of writing. Especially for larger projects, this can be a problem. The problem is [older than March 2016](https://forums.docker.com/t/file-access-in-mounted-volumes-extremely-slow-cpu-bound/8076) - as it's a such a long-running issue, we're including it in the docs here.
-One solution is to use [docker-sync](https://github.com/EugenMayer/docker-sync). 
 
 In simple terms, docker-sync creates a docker container with a copy of all the application files that can be accessed very quickly from the other containers. 
 On the other hand, docker-sync runs a process on the host machine that continuously tracks and updates files changes from the host to this intermediate container.
@@ -1099,6 +1098,26 @@ To change the default forwarded port for ssh:
 
 
 
+<br>
+<a name="Change-the-MySQL-Version"></a>
+## Change the (MySQL) Version
+By default **MySQL 8.0** is running.
+
+MySQL 8.0 is a development release.  You may prefer to use the latest stable version, or an even older release.  If you wish, you can change the MySQL image that is used.
+
+Open up your .env file and set the `MYSQL_VERSION` variable to the version you would like to install.
+
+```
+MYSQL_VERSION=5.7
+```
+
+Available versions are: 5.5, 5.6, 5.7, 8.0, or latest.  See https://store.docker.com/images/mysql for more information.
+
+
+
+
+
+
 <br>
 <a name="MySQL-access-from-host"></a>
 ## MySQL access from host

docker-compose.yml

@@ -194,6 +194,8 @@ services:
     mysql:
       build:
         context: ./mysql
+        args:
+          - MYSQL_VERSION=${MYSQL_VERSION}
       environment:
         - MYSQL_DATABASE=${MYSQL_DATABASE}
         - MYSQL_USER=${MYSQL_USER}

env-example

@@ -92,6 +92,7 @@ PHP_SOCKET=php-fpm:9000
 
 ### MYSQL ##############################################################################################################
 
+MYSQL_VERSION=8.0
 MYSQL_DATABASE=default
 MYSQL_USER=default
 MYSQL_PASSWORD=secret

mysql/Dockerfile

@@ -1,4 +1,5 @@
-FROM mysql:8.0
+ARG MYSQL_VERSION=8.0
+FROM mysql:${MYSQL_VERSION}
 
 MAINTAINER Mahmoud Zalt <mahmoud@zalt.me>