init: use linkage to fetch additional mysql access parameters

Changelog.md

@@ -1,6 +1,7 @@
 # Changelog
 
 **latest**
+- added support for fetching `DB_NAME`, `DB_USER` and `DB_PASS` from the mysql linkage
 - gitlab-shell: upgrade to v.2.0.1
 - added GITLAB_GRAVATAR_ENABLED configuration option
 - added fig.yml

README.md

@@ -290,39 +290,28 @@ mkdir -p /opt/mysql/data
 sudo chcon -Rt svirt_sandbox_file_t /opt/mysql/data
 ```
 
-The updated run command looks like this.
+The run command looks like this.
 
 ```bash
 docker run --name=mysql -d \
+  -e 'DB_NAME=gitlabhq_production' -e 'DB_USER=gitlab' -e 'DB_PASS=password' \
 	-v /opt/mysql/data:/var/lib/mysql \
 	sameersbn/mysql:latest
 ```
 
-You should now have the mysql server running. By default the sameersbn/mysql image does not assign a password for the root user and allows remote connections for the root user from the `172.17.%.%` address space. This means you can login to the mysql server from the host as the root user.
-
-Now, lets login to the mysql server and create a user and database for the GitLab application.
-
-```bash
-docker run -it --rm sameersbn/mysql:latest mysql -uroot -h$(docker inspect --format {{.NetworkSettings.IPAddress}} mysql)
-```
-
-```sql
-CREATE USER 'gitlab'@'172.17.%.%' IDENTIFIED BY 'password';
-CREATE DATABASE IF NOT EXISTS `gitlabhq_production` DEFAULT CHARACTER SET `utf8` COLLATE `utf8_unicode_ci`;
-GRANT SELECT, LOCK TABLES, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER ON `gitlabhq_production`.* TO 'gitlab'@'172.17.%.%';
-FLUSH PRIVILEGES;
-```
+The above command will create a database named `gitlabhq_production` and also create a user named `gitlab` with the password `password` with full/remote access to the `gitlabhq_production` database.
 
 We are now ready to start the GitLab application.
 
 ```bash
 docker run --name=gitlab -d --link mysql:mysql \
-  -e 'DB_USER=gitlab' -e 'DB_PASS=password' \
-  -e 'DB_NAME=gitlabhq_production' \
   -v /opt/gitlab/data:/home/git/data \
   sameersbn/gitlab:7.3.1-3
 ```
 
+The image will automatically fetch the `DB_NAME`, `DB_USER` and `DB_PASS` variables from the mysql container using the magic of docker links and works with the following images:
+ - [sameersbn/mysql](https://registry.hub.docker.com/u/sameersbn/mysql/)
+
 ### PostgreSQL
 
 #### External PostgreSQL Server

assets/init

@@ -57,8 +57,8 @@ SIDEKIQ_CONCURRENCY=${SIDEKIQ_CONCURRENCY:-5}
 DB_TYPE=${DB_TYPE:-}
 DB_HOST=${DB_HOST:-}
 DB_PORT=${DB_PORT:-}
-DB_NAME=${DB_NAME:-gitlabhq_production}
-DB_USER=${DB_USER:-root}
+DB_NAME=${DB_NAME:-}
+DB_USER=${DB_USER:-}
 DB_PASS=${DB_PASS:-}
 DB_POOL=${DB_POOL:-10}
 
@@ -118,13 +118,21 @@ REDIS_PORT=${REDIS_PORT:-6379}
 if [ -n "${MYSQL_PORT_3306_TCP_ADDR}" ]; then
   DB_TYPE=${DB_TYPE:-mysql}
   DB_HOST=${DB_HOST:-${MYSQL_PORT_3306_TCP_ADDR}}
-  DB_PORT=${DB_PORT:-${MYSQL_PORT_3306_TCP_PORT}}
+
+  # support for linked sameersbn/mysql image
+  DB_USER=${DB_USER:-${MYSQL_ENV_DB_USER}}
+  DB_PASS=${DB_PASS:-${MYSQL_ENV_DB_PASS}}
+  DB_NAME=${DB_NAME:-${MYSQL_ENV_DB_NAME}}
 elif [ -n "${POSTGRESQL_PORT_5432_TCP_ADDR}" ]; then
   DB_TYPE=${DB_TYPE:-postgres}
   DB_HOST=${DB_HOST:-${POSTGRESQL_PORT_5432_TCP_ADDR}}
   DB_PORT=${DB_PORT:-${POSTGRESQL_PORT_5432_TCP_PORT}}
 fi
 
+# set default user and database
+DB_USER=${DB_USER:-root}
+DB_NAME=${DB_NAME:-gitlabhq_production}
+
 # fallback to using the internal mysql server
 DB_TYPE=${DB_TYPE:-mysql}
 DB_HOST=${DB_HOST:-localhost}