divanov/test-app-env-json repository overview

test-app is a lightweight Python web application that displays all environment variables of its running container in JSON format. It’s designed for testing and validating Docker or Kubernetes workflows, including Helm charts, Kustomize overlays, and environment variable propagation. Features: Returns all environment variables as JSON via HTTP GET request. Runs a minimal HTTP server on port 8080. Lightweight, based on Python 3.12-slim. Easy to deploy locally with Docker or in Kubernetes clusters. Supports environment variable overrides for dev and prod environments.

Usage: Run with Docker:

docker run -p 8080:8080 divanov/test-app-env-json:0.1.0

Example with custom environment variables:

docker run -p 8080:8080 -e PROD=false -e TEST_VAR=hello divanov/test-app-env-json:0.1.0

Open in browser:

http://localhost:8080

Dockerfile Details:

Base image: python:3.12-slim

Application copied to /app

Exposes port 8080

CMD: python app.py

Intended Use:

Testing containerized deployments.

Validating that environment variables are correctly passed to containers in local Docker, Kind clusters, or Kubernetes deployments.

Can be used as a reference app for Helm + Kustomize workflows.
Example can be find here
https://github.com/ivanov-devops/internal-service-helm-gitops⁠