Nested Maybe..Maybe no more
When I first started writing Haskell, there was a tendency that my codes will shift to the right that it becomes really hard to read. This is mostly due to the use of Maybe or…
Polymorphic association in Ecto (Part I)
Polymorphic association in database is when you have multiple tables that need to refer to the same table. For example, I have table users that contains details like profile information. I then have two tables,…
Piping (|>) to second argument in Elixir
Pipe operator in Elixir is great, you can compose your functions naturally. However, there are times when you want to pipe the input to the second argument. How would you do that? Desugar iex>…
Multi-tenancy with Ecto, Part 1
With Ecto 2.0, there is support for Postgres schema or multiple databases for MySQL. What I am trying to do here is to use Postgres schema to achieve multi-tenancy, and of course using Ecto.…
Django multi tenant issues with Celery + Postgres
You can quickly build a multi-tenant site in Django with the help of this nifty package django-tenant-schemas. It works by assigning each tenant into its own database schema and having one public schema for anything…
Class based Celery task
In the previous post, I showed you how to implement basic Celery task that make use of @task decorator and some pattern on how to remove circular dependencies when calling the task from Flask view.…
Celery integration with Flask
As of Celery version 3.0 and above, Celery integration with Flask should no longer need to depend on third party extension. That's what they said. However, my experience integrating Celery with Flask especially when…
Change IP address for existing nodes in CDH 5.3
Today I discovered way to handle changes of IP address for Hadoop cluster managed by CDH 5.3. I think this should also be applicable for CDH 5.x. Took me couple of hours to…
Creating Brew external command
Recently I had the need to create a homebrew external command to extend homebrew default behavior. My goal is to extend brew deps command by creating a new command brew deps-group. Executing the command will…
Kaggle: Bike Sharing Demand Part 1
Finally had a chance to play around with Kaggle challenge, and bike sharing demand seems to be the easiest to tackle - no domain expertise required or atleast very minimal. This is going to be…