Made the host overridable as well

Dockerfile

@@ -47,8 +47,8 @@ RUN tar -xzf /tmp/v${PHPSAML_VERSION}.tar.gz -C ${WEB_REPO}/functions/php-saml/
 # Use system environment variables into config.php
 RUN cp ${WEB_REPO}/config.dist.php ${WEB_REPO}/config.php && \
     chown www-data /var/www/html/app/admin/import-export/upload && \
-    sed -i -e "s/\['host'\] = 'localhost'/\['host'\] = 'mysql'/" \
-    -e "s/\['user'\] = 'phpipam'/\['user'\] = getenv(\"MYSQL_ENV_MYSQL_USER\")/" \
+    sed -i -e "s/\['host'\] = 'localhost'/\['host'\] = getenv(\"MYSQL_ENV_MYSQL_HOST\") ?: \"mysql\"/" \
+    -e "s/\['user'\] = 'phpipam'/\['user'\] = getenv(\"MYSQL_ENV_MYSQL_USER\") ?: \"root\"/" \
     -e "s/\['pass'\] = 'phpipamadmin'/\['pass'\] = getenv(\"MYSQL_ENV_MYSQL_PASSWORD\")/" \
     -e "s/\['port'\] = 3306;/\['port'\] = 3306;\n\n\$password_file = getenv(\"MYSQL_ENV_MYSQL_PASSWORD_FILE\");\nif(file_exists(\$password_file))\n\$db\['pass'\] = preg_replace(\"\/\\\\s+\/\", \"\", file_get_contents(\$password_file));/" \
     ${WEB_REPO}/config.php

README.md

@@ -23,7 +23,7 @@ Here, we store data on the host system under `/my_dir/phpipam` and use a specifi
 ### Phpipam 
 
 ```bash
-$ docker run -ti -d -p 80:80 -e MYSQL_ENV_MYSQL_USER=root -e MYSQL_ENV_MYSQL_PASSWORD=my-secret-pw--name ipam --link phpipam-mysql:mysql pierrecdn/phpipam
+$ docker run -ti -d -p 80:80 -e MYSQL_ENV_MYSQL_PASSWORD=my-secret-pw--name ipam --link phpipam-mysql:mysql pierrecdn/phpipam
 ```
 
 We are linking the two containers and expose the HTTP port. 
@@ -78,6 +78,7 @@ services:
     environment:
       - MYSQL_ENV_MYSQL_USER=root
       - MYSQL_ENV_MYSQL_PASSWORD=my-secret-pw
+      - MYSQL_ENV_MYSQL_HOST=mysql
     ports:
       - "80:80"
 volumes:
@@ -100,7 +101,6 @@ version: '3'
 services:
   ipam:
     environment:
-      - MYSQL_ENV_MYSQL_USER=root
       - MYSQL_ENV_MYSQL_PASSWORD_FILE=/run/secrets/phpipam_mysql_root_password
     secrets:
       - phpipam_mysql_root_password