Kamal Rails Series Part 4: Configure Redis and Sidekiq

2 min

This article covers adding Redis and Sidekiq to your Kamal deployment. Sidekiq is a popular background job processor for Rails, and it uses Redis as its data store. We’ll build upon our existing Kamal configuration to add these services.

Step 1: Add Redis to Your Gemfile

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# Gemfile
gem "redis", "~> 4.0"

Step 2: Add Sidekiq (Skip if Already Configured)

Add Sidekiq to your Gemfile:

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bundle add sidekiq

Create a sample job:

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rails generate sidekiq:job dummy

Step 3: Configure Redis and Sidekiq in deploy.yml

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#config/deploy.yml

# Name of your application. Used to uniquely configure containers.
service: rubypodcatcher

# Name of the container image.
image: joshio1/rubypodcatcher

# Deploy to these servers.
servers:
  web:
    hosts:
      - <SERVER_IP>
    options:
      network: "private"

  ..other configuration..
  
job:
    hosts:
      - <SERVER_IP>
    cmd: bundle exec sidekiq -q default -q mailers
    options:
      network: "private"

env:
  clear:
    HOSTNAME: rubypodcatcher.com
    DB_HOST: <SERVER_IP>
    RAILS_SERVE_STATIC_FILES: true
    RAILS_LOG_TO_STDOUT: true
    REDIS_URL: "redis://rubypodcatcher-redis:6379/0"
  secret:
    - RAILS_MASTER_KEY

accessories:
  redis:
    image: redis:latest
    host: <SERVER_IP>
    directories:
      - data:/data
    options:
      network: "private"
  • If you haven’t created a private Docker network on your remote server, see the previous article for instructions.
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docker network create -d bridge private
  • Note: Any other configuration in your deploy.yml (like Postgres) doesn’t need to be modified.

Step 4: Deploy Redis

Redis is configured as an accessory. Deploy it with:

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kamal env push
kamal accessory boot redis

Step 5: Deploy Your Application

Deploy your application with the new Redis and Sidekiq configuration:

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kamal deploy

Verify the Setup

To verify Redis is working:

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irb(main):008:0> redis = Redis.new
=> #<Redis client v4.8.1 for redis://rubypodcatcher-redis:6379/0>
irb(main):010:0> redis.set("sample_key", "sample_value")
=> "OK"

To verify Sidekiq is working:

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irb(main):005:0> DummyJob.perform_async
2024-01-18T15:39:15.194Z pid=7 tid=2jb INFO: Sidekiq 7.2.0 connecting to Redis with options {:size=>10, :pool_name=>"internal", :url=>"redis://rubypodcatcher-redis:6379/0"}
=> "2ab8740502724b5d107182cd"

Summary

This article demonstrates how to deploy Sidekiq and Redis with Kamal on a Rails application. This configuration works with both the Hetzner and AWS series. Note that Rails 8 introduces SolidQueue, which uses the database instead of Redis for job storage. I’ll cover SolidQueue with Kamal in a future article.

Hetzner Series:

AWS Series:

Listen to this podcast where DHH talks about Rails and Kamal.

If you would like to search for specific terms or concepts or names in Ruby/Rails podcasts, check out rubypodcatcher.com

Kamal, kamal, Rails, Redis, Ruby, ruby on rails, Sidekiq
This post is licensed under CC BY 4.0 by the author.