https://ianlondon.github.io/blog/deploy-flask-docker-nginx/
Install the prerequisites
Aftersshing into your server, update your packages, then install python, pip, git, and docker. Afterwards, use pip to install virtualenv.
sudo apt-get update
sudo apt-get install python-dev python-pip git docker.io
sudo pip install virtualenv
Watch that you installdocker.ioand notdocker, they’re different things!
install
1 .Set up a virtual environment in a directory called venv with the command virtualenv venv.
Activate the virtual environment with source venv/bin/activate.
2 . Make a file requirements.txt that has all your dependencies in it.
Install your dependencies with pip install -r requirements.txt
Make a flask app at app/main.py. For the Docker image we will use, you need to do two important things:
Make sure the app is really called main.py
Make sure the Flask app variable is really called app. The Flask app variable is declared like app = Flask(..blah blah..). If you call this variable something else like my_app = Flask(..blah blah..), the Docker image won’t find it and it will not work!
file tree
root_project_dir/
Dockerfile
requirements.txt
app/
main.py
venv/
dockerfile
FROM tiangolo/uwsgi-nginx-flask:flask
# copy over our requirements.txt file
COPY requirements.txt /tmp/
# upgrade pip and install required python packages
RUN pip install -U pip
RUN pip install -r /tmp/requirements.txt
# copy over our app code
COPY ./app /app
# set an environmental variable, MESSAGE,
# which the app will use and display
ENV MESSAGE "hello from Docker"
main.py
from pyfiglet import Figlet
import os
from flask import Flask
app = Flask(__name__)
font = Figlet(font="starwars")
@app.route("/")
def main():
# get the message from the environmental variable $MESSAGE
# or fall back to the string "no message specified"
message = os.getenv("MESSAGE", "no message specified")
# render plain text nicely in HTML
html_text = font.renderText(message)\
.replace(" "," ")\
.replace(">",">")\
.replace("<","<")\
.replace("\n","<br>")
# use a monospace font so everything lines up as expected
return "<html><body style='font-family: mono;'>" + html_text + "</body></html>"
if __name__ == "__main__":
app.run(host="0.0.0.0", port=80)
Build and run!
docker build -t flask_ascii .
docker run -p 80:80 -t flask_ascii
Using a different environmental variable
You can overwrite many of the commands specified in the Dockerfile, including the environment variables. To change the $MESSAGE var to something else, use the-eflag (for “Environment”):
docker run -p 80:80 -e MESSAGE="something else" -t flask_ascii
Daemonize it!
If everything’s working, run it as an auto-restarting daemon
docker run -d --restart=always -p 80:80 -v /root/webapp/app:/app -rm=true -t flask_ascii