├── .gitignore
├── Dockerfile
├── app.py
├── requirements.txt
└── templates
└── hello.html
/.gitignore:
--------------------------------------------------------------------------------
1 | venv
2 | .idea
--------------------------------------------------------------------------------
/Dockerfile:
--------------------------------------------------------------------------------
1 | FROM python:3.6-alpine
2 |
3 | RUN pip install flask
4 |
5 | COPY . /opt/
6 |
7 | EXPOSE 8080
8 |
9 | WORKDIR /opt
10 |
11 | ENTRYPOINT ["python", "app.py"]
12 |
--------------------------------------------------------------------------------
/app.py:
--------------------------------------------------------------------------------
1 | from flask import Flask
2 | from flask import render_template
3 | import socket
4 | import random
5 | import os
6 | import argparse
7 |
8 | app = Flask(__name__)
9 |
10 | color_codes = {
11 | "red": "#e74c3c",
12 | "green": "#16a085",
13 | "blue": "#2980b9",
14 | "blue2": "#30336b",
15 | "pink": "#be2edd",
16 | "darkblue": "#130f40"
17 | }
18 |
19 | SUPPORTED_COLORS = ",".join(color_codes.keys())
20 |
21 | # Get color from Environment variable
22 | COLOR_FROM_ENV = os.environ.get('APP_COLOR')
23 | # Generate a random color
24 | COLOR = random.choice(["red", "green", "blue", "blue2", "darkblue", "pink"])
25 |
26 |
27 | @app.route("/")
28 | def main():
29 | # return 'Hello'
30 | return render_template('hello.html', name=socket.gethostname(), color=color_codes[COLOR])
31 |
32 |
33 | if __name__ == "__main__":
34 |
35 | print(" This is a sample web application that displays a colored background. \n"
36 | " A color can be specified in two ways. \n"
37 | "\n"
38 | " 1. As a command line argument with --color as the argument. Accepts one of " + SUPPORTED_COLORS + " \n"
39 | " 2. As an Environment variable APP_COLOR. Accepts one of " + SUPPORTED_COLORS + " \n"
40 | " 3. If none of the above then a random color is picked from the above list. \n"
41 | " Note: Command line argument precedes over environment variable.\n"
42 | "\n"
43 | "")
44 |
45 | # Check for Command Line Parameters for color
46 | parser = argparse.ArgumentParser()
47 | parser.add_argument('--color', required=False)
48 | args = parser.parse_args()
49 |
50 | if args.color:
51 | print("Color from command line argument =" + args.color)
52 | COLOR = args.color
53 | if COLOR_FROM_ENV:
54 | print("A color was set through environment variable -" + COLOR_FROM_ENV + ". However, color from command line argument takes precendence.")
55 | elif COLOR_FROM_ENV:
56 | print("No Command line argument. Color from environment variable =" + COLOR_FROM_ENV)
57 | COLOR = COLOR_FROM_ENV
58 | else:
59 | print("No command line argument or environment variable. Picking a Random Color =" + COLOR)
60 |
61 | # Check if input color is a supported one
62 | if COLOR not in color_codes:
63 | print("Color not supported. Received '" + COLOR + "' expected one of " + SUPPORTED_COLORS)
64 | exit(1)
65 |
66 | # Run Flask Application
67 | app.run(host="0.0.0.0", port=8080)
68 |
--------------------------------------------------------------------------------
/requirements.txt:
--------------------------------------------------------------------------------
1 | Flask
--------------------------------------------------------------------------------
/templates/hello.html:
--------------------------------------------------------------------------------
1 |
2 | Hello from Flask
3 |
4 |
8 | {% if name %}
9 |
Hello from {{ name }}!
10 | {% else %}
11 | Hello, World!
12 | {% endif %}
13 |
14 | {% if contents %}
15 |
18 | {% endif %}
19 |
20 |
21 |
--------------------------------------------------------------------------------