ziraqyoung / sidekiq_cron

Using sidekiq-cron and web in plain Ruby

Sidekiq Cron and web in Plain Ruby

Intro

Sidekiq

• Sidekiq is a simple and efficient background processing library in Ruby.
• It uses threads to handle many jobs at the same time in the same process.

Sidekiq Cron

• Sidekiq Cron runs a thread alongside Sidekiq workers to schedule jobs at specified intervals (using cron notation * * * * * parse by Fugit)
• Checks for new jobs to schedule every 30 seconds and doesnot schedule the same job multiple time, when more than one sidekiq worker is running.
• Schesduling jobs are added only when atleast one sidekiq process is running.
• It is safe to use Sidekiq-cron in envs where multiple sidekiq processes are running

Sidekiq Web

• Build-in-panel(Web UI) to monitor Sidekiq jobs and crons
• You could use System cron jobs and use shell scripts to do scheduling stuffs but sometimes using Ruby is easier.

Setup

• Run bundle init to generate a Gemfile
• Add sidekiq and sidekiq-cron gems and run bundle install

How to Run Sidekiq

• Sidekiq depends on Redis, so make sure its installed.

• You also need a config file for Sidekiq Usually config/sidekiq.yml:

• You also need to define a job for Sidekiq(usually called worker). eg in lib/jobs/sample.rb

• • Include Sidekiq::Worker and define a perform()

• Sidekiq uses to Environment variables to get REDIS URL. REDIS_PROVIDER is like a pointer to the name of the environment variable containing the address. REDIS_PROVIDER=REDIS_URL && REDIS_URL=redis://127.0.0.1:6379/1 To run Sidekiq: REDIS_PROVIDER=REDIS_URL REDIS_URL=redis://127.0.0.1:6379/1 bundle exec sidekiq -C config/sidekiq.yml -r $PWD/lib/jobs/sample.rb

• With this: we can push a job and it will be processed. and sidekiq is ready to handle Sample jobs

How to Add Cron Jobs

• We have already added sidekiq-cron, Next: We are going to add schedule file and tell sidekiq about it.
• The config/schedule.yml is going to define how often the job is processed.
• Next a Ruby script is needed to tell sidekiq about these schedules. This is done in crons.rb
• The Code uses Sidekiq::Cron::Job.load_from_has() where:
• 1. Each schedule name is the main key eg. sample:
  2. The schedule cron is defined by cron, class and queue.
• For this we only need to run Sidekiq only requiring crons.rb bundle exec sidekiq -C config/sidekiq.yml -r ./lib/crons.rb
• If successfull, after every time, an enty is made into logs/logs.log a log entry is made in the console
• You can add as many custom jobs you want in lib/jobs dir. Just remember each job must have a unique class, must include Sidekiq::Worker and define a perform method.
• The register it in config/schedule.yml file with keys/values for cron, class, queue

How to add Web Monitoring

• Sidekiq comes with an inbuild web monitoring panel, easily runnable and is used to monitor jobs and cron jobs
• To run sidekiq/web UI, add the following gems rackup & rack-session then bundle install
• For Rack, a rackup file is need to run Sidekiq::Web panel. Add lib/web/panel.ru
• A valid rack session is required, hence for this securerandom is needed.
• To run sidekiq web: REDIS_PROVIDER=REDIS_URL REDIS_URL=redis://127.0.0.1:6379/1 bundle exec rackup lib/web/panel.ru -o 0.0.0.0 -p 9292 or simply: bundle exec rackup lib/web/panel.ru -o 0.0.0.0 -p 9292
• To use Rack session cookie.
• 1. require 'rack/session'
• 2. use Rack::Session::Cookie, secret: File.read('.session.key'), same_site: true, max_age: 86400
• To run sidekiq web run Sidekiq::Web