This is a guide to write a Kubernetes controller. We will kick off by inspecting the Kubernetes API from inside a pod within the cluster. Minikube suffices for this exercise. But you can conduct the exercise to any Kubernetes cluster.

The controller watches events related to Kubernetes pods using the Kubernetes API. When there is a new event, the controller logs the event’s type and the name of the affected pod. This controller can be extended to perform other actions when pod events occur, such as scaling the number of replicas for a deployment, sending notifications, or triggering a custom script or program.

In this blog post, I will explain how I implemented a graph algorithm to solve the database migration problem in an application pluggable module system.

Prerequisites:

• Working knowledge of Python
• Working knowledge of Graph Theory. Familiar with the terms: Edge, vertex, path, sink, source, digraph, path graph, etc.

Gavika Web Framework has a pluggable module system. The modules can be developed independently. They can be installed, upgraded and removed from the main application. Gavika Web Framework is written using Python, Flask, SQLAlchemy and a bunch of other related technologies and libraries.

You access Python dictionary keys using the syntax:

my_dicy[my_key]

For example:

>>> my_dict = {'food': 'idly'}
>>> my_dict['food']
'idly'

Sometimes, you might want to access the dictionary keys using:

my_dict.my_key

syntax. If you do this is what happens:

>>> my_dict.food
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'dict' object has no attribute 'food'

How can you solve this? Easy.

 pip install attrdict

How do you use the newly installed package?

>>> from attrdict import AttrDict
>>> my_dict = AttrDict({'food': 'idly'})
>>> my_dict.food
'idly'