How to create proper Dockerfile

Question

I'm completely new to Docker, but I have to create Docker Compose of this application.

I decided to start from building an image and run it as one container, so I cloned repository and created following Dockerfile:

    FROM python:2.7-slim
    WORKDIR /flask
    COPY requirements.txt requirements.txt
    RUN pip install -r requirements.txt
    CMD ["python", "routes.py"]

The image was created successfully, but when I used run command I received:

python: can't open file 'routes.py': [Errno 2] No such file or directory

My Dockerfile is in the same directory as routes.py, so I have no idea why he doesn't see it.

EDIT: Copy directory to the container solved the problem with opening file. But the web content it's not display. docker run tagName command returns:

 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger pin code: 262-019-209

However when I type docker container ls my container is not on the list. So maybe he's still not created.

routes.py file:

from flask import Flask, render_template
app = Flask(__name__)

# two decorators, same function
@app.route('/')
@app.route('/index.html')
def index():
    return render_template('index.html', the_title='Tiger Home Page')

@app.route('/symbol.html')
def symbol():
    return render_template('symbol.html', the_title='Tiger As Symbol')

@app.route('/myth.html')
def myth():
    return render_template('myth.html', the_title='Tiger in Myth and Legend')

if __name__ == '__main__':
    app.run(host='0.0.0.0', debug=True)

vivekyad4v · Accepted Answer · 2019-06-18T15:47:01.767

1

You need to copy your current directory/file to the container -

FROM python:2.7-slim
WORKDIR /flask
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY . .
CMD ["python", "routes.py"]

OR

FROM python:2.7-slim
WORKDIR /flask
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY routes.py ./
CMD ["python", "routes.py"]

Make sure to bind it to all hosts i.e 0.0.0.0 instead of localhost.

Ref - Configure Flask dev server to be visible across the network

edited Jun 18 '19 at 15:47

answered Jun 18 '19 at 13:14

vivekyad4v

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Thanks it helps. But when I go to url the display content doesn't show up. Should I change something else in `Dockerfile` or it's caused by different reason? – mariusz Jun 18 '19 at 13:48
It depends on how you run the image. While running you can 'bind' container network's port to your machines network. Docker container has it's own network in your local network. – Doğancan Arabacı Jun 18 '19 at 14:32
@DoğancanArabacı I run it like this: `docker run tagName` – mariusz Jun 18 '19 at 14:38
try with docker run tagName -p 5000:5000 – Doğancan Arabacı Jun 18 '19 at 14:52
Try changing the app.run host. It should bind to 0.0.0.0:5000 instead of localhost. Check the updated answer. Change it in routes.py. – vivekyad4v Jun 18 '19 at 15:46
@vivekyad4v I changed it as you suggested but it wasn't help. – mariusz Jun 18 '19 at 16:05
Add your routes.py file as well. What error are you getting now? Share the container logs. – vivekyad4v Jun 18 '19 at 16:08
I updated mu question. I don't get any error. When I run `docker logs` I receive `No such container` – mariusz Jun 18 '19 at 16:15
Try rebuilding the image & run the container. Check if you see anything in `docker ps -a`. Do a docker logs on exited container. The container will exit if your PY file has issues. – vivekyad4v Jun 18 '19 at 16:21
@vivekyad4v Yes I see it in `docker ps -a`. The log is the same as I run `run` command. – mariusz Jun 18 '19 at 16:55
@vivekyad4v You answer was correct. I need to add `-d` to the `docker run` command. – mariusz Jun 18 '19 at 21:02

How to create proper Dockerfile

1 Answers1