adding nginx-wsgi-flask docker-compose sample

Signed-off-by: grantbirki <grant.birkinbine@gmail.com>
Signed-off-by: Grant Birkinbine <grant.birkinbine@gmail.com>

nginx-wsgi-flask/flask/Dockerfile

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+FROM python:3.9.2-alpine
+
+# upgrade pip
+RUN pip install --upgrade pip
+
+# get curl for healthchecks
+RUN apk add curl
+
+# permissions and nonroot user for tightened security
+RUN adduser -D nonroot
+RUN mkdir /home/app/ && chown -R nonroot:nonroot /home/app
+RUN mkdir -p /var/log/flask-app && touch /var/log/flask-app/flask-app.err.log && touch /var/log/flask-app/flask-app.out.log
+RUN chown -R nonroot:nonroot /var/log/flask-app
+WORKDIR /home/app
+USER nonroot
+
+# copy all the files to the container
+COPY --chown=nonroot:nonroot . .
+
+# venv
+ENV VIRTUAL_ENV=/home/app/venv
+
+# python setup
+RUN python -m venv $VIRTUAL_ENV
+ENV PATH="$VIRTUAL_ENV/bin:$PATH"
+RUN export FLASK_APP=app.py
+RUN pip install -r requirements.txt
+
+# define the port number the container should expose
+EXPOSE 5000
+
+CMD ["python", "app.py"]

nginx-wsgi-flask/flask/app.py

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+from flask import Flask, request, jsonify
+
+app = Flask(__name__)
+
+@app.route('/')
+def hello():
+	return "Hello World!"
+
+@app.route('/cache-me')
+def cache():
+	return "nginx will cache this response"
+
+@app.route('/info')
+def info():
+
+	resp = {
+		'connecting_ip': request.headers['X-Real-IP'],
+		'proxy_ip': request.headers['X-Forwarded-For'],
+		'host': request.headers['Host'],
+		'user-agent': request.headers['User-Agent']
+	}
+
+	return jsonify(resp)
+
+@app.route('/flask-health-check')
+def flask_health_check():
+	return "success"

nginx-wsgi-flask/flask/requirements.txt

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+Flask==1.1.1
+gunicorn==20.0.4

nginx-wsgi-flask/flask/wsgi.py

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+from app import app
+import os
+
+if __name__ == "__main__":
+    app.run(host='0.0.0.0', port=os.environ.get("FLASK_SERVER_PORT"), debug=True)