Kubernetes Watcher Service

The Kubernetes Watcher Service is a Python-based service that watches and detects changes for Kubernetes resources, such as Deployments, StatefulSets, and Jobs.

Features

Watches for changes to Kubernetes resources in real-time.
Logs information about the changes detected.
Supports monitoring of Deployments, StatefulSets, and Jobs.

Usage

Deploy the service in a Kubernetes cluster using a Helm chart. After that, detected changes in the Kubernetes cluster will be displayed in the service logs.

Development

Prerequisites

Python 3.11+
Kubernetes cluster (local or remote)
Kubectl
Helm

Installation and running

Install Python 3.12 if it is not available in your package manager

These instructions are for Ubuntu 22.04. If you're on a different distribution, or - God forbid! - Windows, you should adjust these accordingly.

Also, these instructions are about using Poetry with Pyenv-managed (non-system) Python.

Step 1: Update and Install Dependencies

Before we install pyenv, we need to update our package lists for upgrades and new package installations. We also need to install dependencies for pyenv.

Open your terminal and type:

sudo apt-get update
sudo apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncursesw5-dev xz-utils \
tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev

Step 2: Install Pyenv

We will clone pyenv from the official GitHub repository and add it to our system path.

git clone https://github.com/pyenv/pyenv.git ~/.pyenv
echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init -)"' >> ~/.bashrc
exec "$SHELL"

Step 3: Install Python 3.12

Now that pyenv is installed, we can install different Python versions. To install Python 3.12, use the following command:

pyenv install 3.12

Step 4: Connect Poetry to it

Do this in the template dir. Pycharm will automatically connect to it later

poetry env use ~/.pyenv/versions/3.12.1/bin/python

(change the version number accordingly to what is installed)

Finally, verify that Poetry indeed is connected to the proper version:

poetry env info

If you don't have Poetry installed run:

pip install poetry

Install dependencies:

poetry config virtualenvs.in-project true
poetry install --no-root --with dev,test

Install pre-commit hooks:

poetry run pre-commit install

Running tests:

poetry run pytest

Launch the service:

poetry run python -m app.main --config ./etc/config.yaml

Integration tests

Pytest tests with mark vcr support two modes.

Unit-test mode with network calls mocked.
```
poetry run pytest --mark=vcr
```
Integration test mode with real network calls.
```
poetry run pytest --mark=vcr --disable-vcr
```

It works via VCR.py and pytest-vcr.

Manual build and deployment on minikube

Install minikube.
Start minikube:

minikube start

Build a docker image:

docker build . -t kg-exporter:latest

Upload the docker image to minikube:

minikube image load kg-exporter:latest

Deploy the service:

helm upgrade --install kg-exporter-app ./charts/app --set image.repository=kg-exporter --set image.tag=latest --version 0.1.0

Release

To create a release, add a tag in GIT with the format a.a.a, where 'a' is an integer. The release version for branches, pull requests, and other tags will be generated based on the last tag of the form a.a.a.

GitHub Actions

GitHub Actions triggers testing, builds, and application publishing for each release.
https://docs.github.com/en/actions

After execution
The index.yaml file containing the list of Helm charts will be available at https://glaciation-heu.github.io/kg_exporter/helm-charts/index.yaml.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT

glaciation-heu/kg_exporter