I tried to introduce CircleCI 2.0 to Rails app

Overview

I would like to organize the introduction of CircleCI. As a prior knowledge, there are many articles such as CircleCI Official Tutorial and other articles, so I think that it will not be a problem for learning, but this time I would like to look at the code as an arrangement of what I learned. I will.

[Addition] 2021-1-16 Click here for articles that support JavaScript!

What is CircleCI

CircleCI is a Saas type CI/CD service. Specifically, when you push it to the GitHub repository, the process of building, testing, and deploying the app will be executed automatically.

Installation procedure

1. Link CircleCI and GitHub
2. Select the repository (app) currently created on CircleCI
3. Create a .circleci directory and a config.yml file in the root directory of the repository selected in your local environment.
4. Create config/database.yml.ci for testing
5. After setting config.yml, go back to the CircleCI repository, click ** Use Existing Config, and select build **.
6. Push to GitHub repository

CircleCI settings

I wrote it like this.

config:.circleci/config.yml

version: 2
jobs:
  build:
    docker:
      - image: circleci/ruby:2.6.6-node-browsers #Match your Ruby version
        environment: #Use environment variables
          - BUNDLER_VERSION: 2.0.2 #Match your bundler version
          - RAILS_ENV: 'test'
      - image: circleci/mysql:8.0 #Match your version of MySQL
        command: [--default-authentication-plugin=mysql_native_password]
        environment:
          - MYSQL_USER: root
          - MYSQL_DB: ci_test

    working_directory: ~/myapp
    
    steps: #Steps to install in a container
      - checkout #Start installation

      - restore_cache: #Find a cache with a key that matches the key template
          keys:
            - v1-dependencies-{{ checksum "Gemfile.lock" }}
            - v1-dependencies-

      - run:
          name: install dependencies
          command: |
            gem install bundler -v 2.0.2
            bundle install --jobs=4 --retry=3 --path vendor/bundle

      - save_cache: #Create cache
          paths:
            - ./vendor/bundle
          key: v1-dependencies-{{ checksum "Gemfile.lock" }}

      - run: mv config/database.yml.ci config/database.yml 

      - run: yarn install
      #DB creation
      - run: bundle exec rake db:create
      - run: bundle exec rake db:schema:load
      #Run the test
      - run:
          name: run tests
          command: |
            mkdir /tmp/test-results
            TEST_FILES="$(circleci tests glob "spec/**/*_spec.rb" | \
              circleci tests split --split-by=timings)"
            sudo gem install bundler
            sudo gem install rspec
            sudo gem install rspec-core
            bundle exec rspec \
              --format progress \
              --format RspecJunitFormatter \
              --out /tmp/test-results/rspec.xml \
              --format progress \
              $TEST_FILES
      #Save test results
      - store_test_results:
          path: /tmp/test-results
      - store_artifacts:
          path: /tmp/test-results
          destination: test-results

config:config/database.yml.ci

test:
  adapter: mysql2
  encoding: utf8
  pool: 5
  username: 'root'
  port: 3306
  host: '127.0.0.1'
  database: ci_test

Details

Authentication plugin 'caching_sha2_password' cannot be loaded

command: [--default-authentication-plugin = mysql_native_password] Added this description.

Mysql2::Error: Unknown MySQL error This error is a MySQL not found error. I reviewed the settings, thinking that I used to go there locally.

If you don't take the ** consistency ** of the username and databaseindatabase.yml.ci and the MYSQL_USER and MYSQL_DB in config.yml, you'll get an error like this:

The test does not pass

It was solved by the image containing circleci/ruby: 2.6.6-node-browsers node and run: yarn install. By setting -tag + -node, it seems that the state of the build container can be fixed and unexpected changes from upstream can be prevented. See Best Practices in the circleci image for more information.
** * This time, no tag is attached. ** (We are looking for the cause because an error will occur.)

important point

--Watch out for indentation ――Do not push one or eight

This article was helpful. I was late to notice and messed up the repository a bit. ..

You can test grammar checks and jobs locally before pushing using the CircleCI CLI. Please see the article for details.

――Proceed while understanding what you are doing

I haven't fully understood it yet, but it may be faster to understand ** if you think about what you are doing and how the file is executed. ..

Summary

--Introduction is relatively easy due to the large amount of information. ――However, it takes time to understand, so first move your hand to grasp the flow. --You also need to know Docker, so you need to review it again.

References

-CircleCI Official

• Configuring CircleCI -CircleCI pre-built Docker image
• dockerhub -You haven't done Push debugging, right? Frequently Used CircleCI Debugging Method -I've just started CircleCI, so I've summarized it in an easy-to-understand manner -I've just started Docker, so I've summarized it in an easy-to-understand manner -[CircleCI] Settings and error handling memo -IT Glossary that makes you feel like you understand even if you don't understand it

[Addition] 2021-1-16 Click here for articles that support JavaScript!