Build blueapp Docker image.txt

Build mbigras/blueapp:v1 Docker image.

cat <<'Dockerfile' | docker build -t mbigras/blueapp:v1 -
# syntax=docker/dockerfile:1.3-labs see https://www.docker.com/blog/introduction-to-heredocs-in-dockerfiles/
FROM python
RUN pip install flask gunicorn
RUN cat <<App >app.py
import os

from flask import Flask, jsonify
app = Flask("blueapp")
@app.route("/")
def ui():
	return jsonify(
		color=os.environ["COLOR"],
		corners=os.environ["CORNERS"],
		widgets=os.environ["WIDGETS"],
	)
App
ENV PORT=8080
ENTRYPOINT ["gunicorn", "app:app"]
Dockerfile

Run mbigras/blueapp:v1 Docker container.

docker run -it -p 8080:8080 -e COLOR=blue -e CORNERS=rounded -e WIDGETS=w1,w2,w3 mbigras/blueapp:v1

$ curl localhost:8080
{"color":"blue","corners":"rounded","widgets":"w1,w2,w3"}

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: blueapp
spec:
  selector:
    matchLabels:
      app: blueapp
  replicas: 3
  template:
    metadata:
      labels:
        app: blueapp
    spec:
      containers:
      - name: blueapp
        image: mbigras/blueapp:v1
        envFrom:
          - configMapRef:
              name: blueapp

kustomization.yaml

kind: Kustomization
apiVersion: kustomize.config.k8s.io/v1beta1
resources:
  - deployment.yaml
configMapGenerator:
  - name: blueapp
    literals:
      - COLOR=cornflowerblue
      - CORNERS=rounded
      - WIDGETS=w2,w1,w3

This gist is for kubernetes/kubectl#686 (comment) comment.