Start Using GitLab CI

I've just started using GitLab CI to run the test for my private project today.

Target Project

mmyoji/starpotate | GitLab

This is a dockerized Rails project using MySQL and yarn.

Documents

Getting started with GitLab CI/CD

Start from the document above when you want to use GitLab CI.

Just prepare the .gitlab-ci.yml on the root of your project.

The example in the page doesn't touch "using docker images" and you can check the next doc.

Using Docker images

For most modern projects, this document is enough to write your own gitlab-ci.yml.

You just set the base docker image as image: and additional services as services:. It is almost like docker-compose.yml and you will be able to catch up the way of gitlab-ci.yml if you're familiar with docker-compose.yml.

Using MySQL

I use MySQL for the data storage of the app and use mysql docker image.

You're just careful with MySQL Host when using MySQL image on .gitlab-ci.yml.

As the document says, you have to set the host value as mysql in it.

Suppose your config/database.yml is like following:

# config/database.yml

default: &default
  adapter: mysql2
  encoding: utf8mb4
  collation: utf8mb4_bin
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: <%= ENV.fetch("DB_USER") %>
  password: <%= ENV.fetch("DB_PASS") %>
  host: <%= ENV.fetch("DB_HOST") %>

development:
  <<: *default
  database: app_development

test:
  <<: *default
  database: app_test

You can set the DB_HOST variable in .gitlab-ci.yml like this:

# .gitlab-ci.yml

variables:
  DB_HOST: mysql

The other things are not so difficult and you can try it.