Lab #7: Create a Docker image with EXPOSE instruction

Pre-requisite:

Tested Infrastructure

<table class="tg"> <tr> <th class="tg-yw4l">Platform</th> <th class="tg-yw4l">Number of Instance</th> <th class="tg-yw4l">Reading Time</th> </tr> <tr> <td class="tg-yw4l"> Play with Docker</td> <td class="tg-yw4l">1</td> <td class="tg-yw4l">5 min</td> </tr> </table>

Pre-requisite

Create an account with DockerHub
Open PWD Platform on your browser
Click on Add New Instance on the left side of the screen to bring up Alpine OS instance on the right side

Assignment:

Create an image with expose instruction
Create hello.py
Create dockerfile
Build dockerfile
Run application

Creating directory

mkdir pythonexposeapp 
cd pythonexposeapp

Creating hello.py

vi hello.py

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "welcome to Dockerlabs!! successfully done !!"

if __name__ == "__main__":
    app.run()

Creating Dockerfile

vi Dockerfile

FROM python:3.5

# Update and install dependencies
RUN apt-get update
RUN pip install Flask

# Add code
ADD . /opt/webapp/

# Set the working directory
WORKDIR /opt/webapp

# Set environment variables
ENV FLASK_APP=hello.py

# Expose the application's port
EXPOSE 5000

# Run the application
CMD ["flask", "run", "--host=0.0.0.0"]

Building Dockerfile

 docker build -t pythonapp:v1 .

Running Docker image

sangam$ docker run -p 5000:5000 pythonapp:v1
 * Serving Flask app "hello.py"
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)
172.17.0.1 - - [17/Aug/2019 12:21:20] "GET / HTTP/1.1" 200 -
172.17.0.1 - - [17/Aug/2019 12:21:20] "GET /favicon.ico HTTP/1.1" 404 -

By now, the application should be accessible http://0.0.0.0:5000/

Contibutor

Sangam Biradar

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