DEV Community

Cover image for Deploy Rails app with PostgreSQL, Redis and Sidekiq on Production and Staging using Kamal
Stoyan
Stoyan

Posted on

Deploy Rails app with PostgreSQL, Redis and Sidekiq on Production and Staging using Kamal

#rails #kamal

Step 1: Install Kamal

Article is for those who already have installed kamal with ready to use servers but if you doesn't, just take a look on Kamal gem and make sure that is installed on your local machine:

gem install kamal
Enter fullscreen mode Exit fullscreen mode

Step 2: Configure Deployment Settings

Move into the application directory and run:

kamal init
Enter fullscreen mode Exit fullscreen mode

This process generates a deployment configuration file named config/deploy.yml, in addition to several other files. We will now delve into the different sections of the deploy.yml configuration file to understand their purposes and configurations.

deploy.yml

# Name of your application. Used to uniquely configure containers. service: myrailapp # Name of the container image. image: mydockerhubuser/myrailapp # Credentials for your image host. registry: username: mydockerhubuser password: - KAMAL_REGISTRY_PASSWORD # Inject ENV variables into containers (secrets come from .env). # Remember to run `kamal env push` after making changes! env: clear: RAILS_SERVE_STATIC_FILES: true DB_HOST: 10.0.0.6 secret: - RAILS_MASTER_KEY - POSTGRES_PASSWORD volumes: - "/storage:/rails/storage" # Use accessory services (secrets come from .env). accessories: db: image: postgres:15 host: 66.100.100.10 port: 5432 env: clear: POSTGRES_ROOT_HOST: '%' POSTGRES_USER: 'db_us1_app' secret: - POSTGRES_PASSWORD directories: - data:/var/lib/postgresql/data redis: image: redis:latest host: 61.111.111.1 port: 6379 directories: - data:/var/lib/redis/data
Enter fullscreen mode Exit fullscreen mode

In our example, we utilize DockerHub and connect to it using the DockerHub username 'mydockeruser' and the repository name 'myrailapp' (which can be private). The password is configured via the KAMAL_REGISTRY_PASSWORD environment variable within the .env file, located in the root directory of the application. Additionally, it's crucial to remember to list .env files in the .gitignore to prevent them from being tracked and uploaded to version control systems.DB_HOST using local IP of the machine but you can use your public server address as well.

.env

KAMAL_REGISTRY_PASSWORD=dckr_pat_382391340045824911111 RAILS_MASTER_KEY=25345k34j543132432m5j4234 POSTGRES_PASSWORD=s0meR@andomPasw0rt
Enter fullscreen mode Exit fullscreen mode

To separate the staging and production environments, we should create two additional files: deploy.staging.yml for staging and deploy.production.yml for production. In this scenario, the staging environment will be deployed on a single server, while the production environment will be deployed across two servers. Both environments will share a common server for the database and jobs (utilizing a Redis server), albeit with different databases to ensure separation of staging and production data.

deploy.staging.yml

servers: web: hosts: - 60.100.100.101 job: hosts: - 61.111.111.1 cmd: bundle exec sidekiq -e staging env: clear: POSTGRES_DB: app_staging RAILS_ENV: staging
Enter fullscreen mode Exit fullscreen mode

deploy.production.yml

servers: web: hosts: - 60.100.100.102 - 60.100.100.103 job: hosts: - 61.111.111.1 cmd: bundle exec sidekiq -e production env: clear: POSTGRES_DB: app_production RAILS_ENV: production
Enter fullscreen mode Exit fullscreen mode

Do not forget to create .env.staging as well which can be a copy of the .env if the credentials are the same.

Step 3: Deploy Application

kamal setup
Enter fullscreen mode Exit fullscreen mode

Daily operations:

kamal deploy -d staging
Enter fullscreen mode Exit fullscreen mode

or

kamal deploy -d production
Enter fullscreen mode Exit fullscreen mode

Check kamal docs for more commands and use cases.

Top comments (0)