Super Duper Minikuber

A simple Python 3 Flask app with code to run the app in a container in minikube with load balancing

Initial checkout and setup of codebase

• Open terminal and move to a suitable directory on your machine
• Run git clone git@github.com:robcharlwood/super-duper-minikuber.git
• Run cd super-duper-minikuber

Installation

To install the project locally you need to run make install. You can also pass VENV and PYTHON_EXE keyword arguments to the make file to configure the installation e.g

• make install - Installs dependencies with defaults
• make install VENV=foo - Installs into a virtualenv named foo
• make install PYTHON_EXE=python3.7 - Installs with a specific python interpreter, example values might be python or python3.6. This defaults to python3.

Please ensure that you have kubectl and minikube installed on your system and that they are both on the system path.

Deploying the app to minikube

Once the steps above have been run, you should have a virtualenv setup with ansible and test dependencies installed. Your local instance of minikube will have also been, cleaned, reset and started ready to accept our deployment. The next step is to run our make command which will execute ansible to run configuration management on the cluster. This includes installing our kubernetes namespace and our kubernetes deployment and service. Again for real production projects, you would be better off installing your app using something like Helm Tiller with TLS enabled. You would then just use ansible to configure RBAC, role bindings, cluster role bindings and run Helm Tiller etc. However, to keep this example simple, we are just going to use ansible to do everything. So let's crack on and run the commands below.

• make run_ansible

Once that is complete, we'll check out setup with a few quick commands

• kubectl get ns - shows our new namespace
• kubectl get pods -n superduperminikuber - shows our helloworld app pods
• kubectl get services -n superduperminikuber - shows our load balancing service

Once all of our pods are ready, our deployment is complete. You can check for the deployment being ready using the command below:

kubectl get deployments -n superduperminikuber

Once this command shows 4 under the AVAILABLE column, we are ready to view our deployed app. To see our app running under our load balancer enter the below command in to your terminal. This will cause a new browser window to open and our app to load.

minikube service helloworld --namespace superduperminikuber

You should now see the hello world homepage along with the current pod's IP, name and namespace. If you refresh this page over and over, you will see the IP address of the POD change showing the load balancer in action.

Running tests

To run the tests for the project locally you need to run make test. This will run pytest with coverage. Please note that if you have not followed the previous Installation steps above and run make install, this will not work.

Continuous Integration

This project uses Travis CI for continuous integration. This platform runs the project tests and test coverage. Coverage is handled with Python's coverage library, but also uses the SaaS service coveralls.io for visibility on coverage.

Project Docker Hub Builds

To build the image that will be deployed to our minikube instance, we use Docker Hub's GitHub integration. This integration allows Docker Hub to automatically detect changes to the project's Dockerfile and build and tag relevant versions of the build to store in their registry. Obviously for private projects, images would not be hosted on a public docker hub. However, for this open source example project it will be fine.

Versioning

This project uses git for versioning. For the available versions, see the tags on this repository.

Authors

• Rob Charlwood - Bitniftee Limited

Changes

Please see the CHANGELOG.md file additions, changes, deletions and fixes between each version

License

This project is licensed under the MIT License - see the LICENSE.md file for details