I am building and running this docker container. It is running a simple flask server. But when I run, it exited right after.
This is my Dockerfile
FROM python:3
WORKDIR /usr/src/app
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt
COPY . .
EXPOSE 8080
# CMD ["python3", "-m", "http.server", "8080"]
CMD ["python3", "./py_server.py"]
and this is py_server.py
from flask import Flask
app = Flask(__name__)
PORT = 8080
#app.route('/')
def hello_world():
return "Hello World"
if __name__ == '__main__':
app.run(PORT)
this is how I build and run the container respectively.
build:
docker build -t banuka/python-venv .
run:
docker run -dit -p 8080:8080 --name server1 banuka/python-venv:latest
Can someone tell me what I do wrong?
There are several issues:
You want the -it parameter, not -dit:
docker run -it -p 8080:8080 --name server1 banuka/python-venv:latest
You are passing PORT as a variable to the app.run() function, so that it is interpreted as the first host parameter, rather than what you want, which is for it to be the port parameter. What you want is this: app.run(port=8080)
As #Alexandre pointed out, if you're accessing the host remotely, then you need to explicitly bind it to host='0.0.0.0', so we need app.run(host='0.0.0.0',port=8080)
You have a bug in your Flask Code. You're trying to configure Flask Server PORT in a wrong way. This will throw the error you're experiencing:
AttributeError: 'int' object has no attribute 'startswith'
You should configure your Flask Server Port with the following way
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return "Hello World"
if __name__ == '__main__':
app.run(host='0.0.0.0',port=8080)
The documentation: https://flask.palletsprojects.com/en/1.1.x/api/#flask.Flask.run
EDIT: Added host='0.0.0.0' so you can access your Flask Server remotely.
you are maybe running procces that finishes and then exit ?
if you run you py script and it finishes so your container will be closed to ...
try using while(true) //and then your code
Related
I'm trying to create a simple web application container within Ubuntu-WSL2 with the help of the Docker. So I've built my container creating my-simple-webapp folder and within that folder, I've created Dockerfile and app.py files;
Dockerfile
FROM ubuntu:16.04
RUN apt-get update && apt-get install -y python python-pip
RUN pip install flask
COPY app.py /opt/
ENTRYPOINT FLASK_APP=/opt/app.py flask run --host=0.0.0.0 --port=8080
app.py
import os
from flask import Flask
app = Flask(__name__)
#app.route("/")
def main():
return "Welcome!"
#app.route('/how are you')
def hello():
return 'I am good, how about you?'
if __name__ == "__main__":
app.run(host="0.0.0.0", port=8080)
When I run the command docker build ./my-simple-webapp it works without error. However when I use my browser to connect my container typing 172.17.0.2:8080, o.o.o.o:8080 or localhost:8080 connection times out.
Resource : https://github.com/mmumshad/simple-webapp-flask
If all you run is docker build... then you still need to start your container with docker run....
You can open the docker dashboard (in your Windows tray) to see if your container is actually running.
To actually run your app you need to start a container. First, build the image:
docker build -t simple-webapp-flask .
Then start a container using the image, with 8080:8080 mapping from container to your host:
docker run -p 8080:8080 simple-webapp-flask
If you want to deploy your flask application, you need to choose from the following options:
https://flask.palletsprojects.com/en/1.1.x/deploying/
The way you are trying to do it, can be used only for development purposes.
I have a Python Flask App running inside a Docker container in the default port 500. This is on a Ubuntu server.
I am able to access the Flask App through local host as follows:
URL = "http://127.0.0.1:5000/get_image"
Would like to know how to expose this server to outside world. I would like to use the server IP to expose the service so that others can access it as well.
Can some one guide on how to expose this docket to internet? Thank you
You should first put "0.0.0.0" as host for flask. Next you need to expose your docker port.
Flask file:
from flask import Flask
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class HelloWorld(Resource):
def get(self):
return {'hello': 'world'}
api.add_resource(HelloWorld, '/get_image')
if __name__ == '__main__':
app.run(debug=True, host='0.0.0.0')
Dockerfile
FROM python:3.7
COPY . /app
WORKDIR /app
RUN pip install -r requirements.txt
ENTRYPOINT ["python"]
CMD ["app.py"]
Build the docker image
docker build -t docker_flask:latest .
Run the image
docker run -d -p 5000:5000 docker_flask:latest
After checking everything is running fine in local, push the image to docker registry using docker push command. Then deploy the image on kubernetes or VM
I am running Flask application in Python using docker-compose. I am able to run the Flask app using 5000 port. I am trying to run it on 6000 besides another Flask app running on 5000. But I am unable run it on 6000 port. Any help would be appreciated.
docker-compose.yml
version: '3.8'
services:
web:
build: ./web
ports:
- "6000:5000"
app.py
if __name__ == '__main__':
app.run(host='0.0.0.0', port=5000, debug=True)
Dockerfile:
FROM python:3
COPY . /app
WORKDIR /app
RUN pip install -U pip
RUN pip install -r requirements.txt
ENTRYPOINT ["python"]
CMD ["app.py"]
requirements.txt
Flask==1.1.1
Port 6000 is listening. I am able to get a connection succeeded by executing nc command with host and port.
I am unable to run the app on port 6000.
I got the following when I hit http://#{HOST_IP}:6000 in browser
This site can’t be reached
The web page at http://#{HOST_IP}:6000/ might be temporarily down or it may have moved permanently to a new web address.
6000 is unsafe port that is why browser not allowing to access the application.
how-to-fix-err-unsafe-port-error-on-chrome-when-browsing-to-unsafe-ports
But you should not allow this port, just try to publish another port.
version: '3.8'
services:
web:
build: ./web
ports:
- "5001:5000"
For downvoter
Here is Github Repo to verify this
git clone https://github.com/Adiii717/dockerize-flask-app.git
cd dockerize-flask-app/
# this will not work in the browser
PORT=6000 docker-compose up
You haven't defined any routes. The app server has no idea what routes are available nor does it know what you want to return, so you need to specify that.
Here's a more complete version of app.py
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello, World!'
if __name__ == '__main__':
app.run(host='0.0.0.0', port=5000, debug=True)
Please refer to the Flask tutorial for a minimal app.
I am newbie to Docker and Python.I have created a simple python application using Flask .I would like to run it in a Docker container.The docker container shows it is running.However when I access the url ,I get localhost didn’t send any data.
docker container ls shows my container running on localhost and port no 8081
app.py
from flask import Flask, redirect, url_for, request
app = Flask(__name__)
#app.route("/hello", methods=["GET","POST"])
def hello():
return "Hello World!"
if __name__ == '__main__':
app.run(debug=True, port=8081,host='0.0.0.0')
Dockerfile
FROM python:2.7
ADD app.py /
RUN pip install flask
EXPOSE 8081
CMD ["flask", "run", "--host=0.0.0.0"]
CMD ["python", "app.py", "--host=0.0.0.0"]
When I run the same app.py in my local environment.I get the desired data on the localhost url. Could someone guide me in the right direction?
Image is tagged dockerimage:latest and I run it with:
docker run -it -p 8081:8081 dockerimage
And checking for the container with docker container ls shows:
0.0.0.0:8081->8081/tcp
Everything seems fine in your Dockerfile and the Flask script, but I will suggest two thing.
Update base image to python:3.7 as 2.7 will reach its end of life.
Remove CMD ["flask", "run", "--host=0.0.0.0"] this as there is only one CMD per dockerfile.
FROM python:3.7.4-alpine3.10
RUN pip install flask
ADD app.py /
EXPOSE 8081
CMD ["python", "app.py", "--host=0.0.0.0"]
Now run the container
docker run -it --name my_app --rm -p 8081:8081 dockerimage
Open the browser and hit
http://localhost:8081/hello
or
docker exec -it my_app ash -c "apk add --no-cache curl && curl localhost:8081/hello"
One of the above should work.
If you the second command work then something wrong with host configuration.
I am looking build a simple web application using Flask, Docker, and Google Container Engine. I have specified the following DockerFile:
# Use an official Python runtime as a base image
FROM python:2.7-slim
# Set the working directory to /app
WORKDIR /app
# Copy the current directory contents into the container at /app
ADD . /app
# Install any needed packages specified in requirements.txt
RUN pip install -r requirements.txt
# Make port 80 available to the world outside this container
EXPOSE 8080
# Define environment variable
ENV NAME World
# Run app.py when the container launches
CMD ["python", "app.py"]
Note I am exposing port 8080.
Here is my simple Flask application:
from flask import Flask, jsonify
from flask import make_response
app = Flask(__name__)
tasks = [
{
'type': 'order',
'contents':[1,2,3,4,5,6,7,8,9,10]
}
]
#app.route('/', methods=['GET'])
def get_tasks():
return jsonify({'tasks': tasks})
#app.errorhandler(404)
def not_found(error):
return make_response(jsonify({'error': 'Not found'}), 404)
if __name__ == '__main__':
app.run(host='0.0.0.0', port=8080)
Note host='0.0.0.0' and port=8080.
I run the docker container locally, successfully:
docker run --rm -p 8080:8080 gcr.io/${PROJECT_ID}/hello-node:v1
However, when I deploy the application using the Google Container Engine I am not able to access the application via the external port provided by kubectl get service.
I run the following to deploy a Pod:
kubectl run hello-world --image=gcr.io/${PROJECT_ID}/hello-node:v1 --port 8080
I run the following commands to create a Service to access from the internet:
kubectl expose deployment hello-world --type=LoadBalancer --port 8080
Why am I not able to access the service? It seems I have opened port 8080 within every step 1) Flask application 2) Dockerfile 3) Pod Deployment 4) Service creation.
I think you should point out the target port as well when exposing your deployment, like this:
kubectl expose deployment hello-world --type=LoadBalancer --port=8080 --target-port=8080
Hope it helps