CODEWITHSUNDEEP
pythonshelldockerdockerfilemultiple-processes
Shubham Jain
Shubham Jain

Reputation: 1016

Running Multiple python processes in Docker

I am new to docker, trying to run multiple python processes in docker. Though it's not recommended, however, it should work as suggested here "https://docs.docker.com/engine/admin/multi-service_container/"

My Dockerfile :

FROM custom_image
MAINTAINER Shubham 
RUN apt-get update -y
COPY . /app
WORKDIR /app
RUN pip install -r requirements.txt
ENTRYPOINT ["/bin/bash"]
CMD ["start.sh"]

start.sh : 

nohup python flask-app.py &
nohup python sink.py &
nohup python faceConsumer.py &
nohup python classifierConsumer.py &
nohup python demo.py &
echo lastLine

run command : 

docker run --runtime=nvidia -p 5000:5000 out_image

Is it possible to run multiple processes without supervisord or docker-compose?

update: not getting any error, only "lastLine" is getting printed and docker container exits.

Upvotes: 5

Views: 14365

Answers (3)

six8
six8

Reputation: 2990

Docker docs has examples of how to do this. If you're using Python, then using supervisord is a good option.

FROM ubuntu:latest
RUN apt-get update && apt-get install -y supervisor
RUN mkdir -p /var/log/supervisor
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
COPY my_first_process my_first_process
COPY my_second_process my_second_process
CMD ["/usr/bin/supervisord"]

The advantage of this over running a bunch of background processes is you get better job control and processes that exit prematurely will be restarted.

Upvotes: 3

meliora245
meliora245

Reputation: 53

You can also run in detached mode or redirect the nohup to log/nohup.out as default docker runs the command by socket, redirection does not happen.

Upvotes: 0

Hannu
Hannu

Reputation: 12215

Your problem is putting everything in background. Your container starts, executes all commands and then exits when CMD process finishes - despite background processes running. Docker does not know that.

You could try running everything else in background but then 

python demo.py

as it is. This would cause the process to stay alive assuming demo.py does not exit.

Upvotes: 1

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