The text below refers to deploying the application to EYK. We need a new Readme to show how it's deployed on EYC Stack v7.

KontainerYard example-application-2: background_jobs

A minimalist Rails application created to test background workers on KY.

About the code

The applicaton is basically the rails_activejob_example that we have been using for testing. The required resources for the original version of the rails_activejob_example application were database and redis in the case of sidekiq. In order to keep things simple we will pack in the same container (== the same pod in deis) all the required components:

• the database service (sqlite)
• the redis server

The configuration files that will need attantion are:

• config/database.yml
• config/initializers/sidekiq.rb

In the config/database.yml we just say that we want to use the sqlite database, while in config/initializers/sidekiq.rb we state which redis to use. In this simple example we could ommit the config/initializers/sidekiq.rb since as per the sidekiq documentation:

By default, Sidekiq tries to connect to Redis at localhost:6379. This typically works great during development but needs tuning in production.

Another interesting point is the command that will start all the services. This is defined in the Dockerfile:

CMD redis-server --daemonize yes && bundle exec sidekiq --daemon && bundle exec rails server -b 0.0.0.0 -p 5000 -e development

Obviously we are trying to make a container behave like a virtual machine wehre all services run in one place. For this example it is ok, but further on we will split the services into multiple containers (pods).

Run the code locally

You may run the code locally using Docker. The commands would be:

docker build --tag example-application-2 .
docker run --rm -ti --name=persistent_harry -p 5000:5000 example-application-2

Then you may visit (the last url will add some jobs): http://localhost:5000 http://localhost:5000/sidekiq/ http://localhost:5000/enqueue-jobs/10

Run the code on KontainerYard

The step by step procedure would be:

1. initialize your working directory:

ilias@ilias-LubuntuVM:[~/KontainerYard/JFPlayground/ky_school]: git init

2. Create the deis application:

ilias@ilias-LubuntuVM:[~/KontainerYard/JFPlayground/ky_school]: deis apps:create ilias-ky-school --remote=deis-ilias-ky-school

3. Make sure that the remote is correctly set:

ilias@ilias-LubuntuVM:[~/KontainerYard/JFPlayground/ky_school]: git remote -v
deis-ilias-ky-school    ssh://[email protected]:2222/ilias-ky-school.git (fetch)
deis-ilias-ky-school    ssh://[email protected]:2222/ilias-ky-school.git (push)

4. Add your changes to git:

ilias@ilias-LubuntuVM:[~/KontainerYard/JFPlayground/ky_school]: git add -A

5. Commit you changes (locally):

ilias@ilias-LubuntuVM:[~/KontainerYard/JFPlayground/ky_school]: git commit -m "First commit" 

6. Deploy the application

ilias@ilias-LubuntuVM:[~/KontainerYard/JFPlayground/ky_school]: git push deis-ilias-ky-school master

7. View the details of the application after deployment

deis info --app=ilias-ky-school
=== ilias-ky-school Application
updated:  2020-05-16T14:03:56Z
uuid:     ec4d1aae-5eac-48e2-bdfd-b7f50fccd0d0
created:  2020-05-16T09:49:28Z
url:      ilias-ky-school.jfuechsl-playground.kontaineryard.io
owner:    igiannoulas
id:       ilias-ky-school

=== ilias-ky-school Processes
--- web:
ilias-ky-school-web-7cc56554bd-8kzlz up (v2)

=== ilias-ky-school Domains
ilias-ky-school

=== ilias-ky-school Label
No labels found.

8. Visit the application in the urls (the last url will add some jobs):

http://ilias-ky-school.jfuechsl-playground.kontaineryard.io/ http://ilias-ky-school.jfuechsl-playground.kontaineryard.io/sidekiq http://ilias-ky-school.jfuechsl-playground.kontaineryard.io/enqueue-jobs/10