How to run multiple commands on docker container on startup?

Question

I have Flask application container which has to run on port 5000.

I also have a background process which is related to queue. This process has an infinite loop which is why I want to run it in background.

I'm using docker-compose.yml file for creating container. For now, I'm able to run only one command which is to make the flask server up.

flask run --host=0.0.0.0 --port 5000. I'm using the command option in docker-compose .

This is the command I want to run in background python app/workload/services/queue_services.py > qlog.txt.

When I put the background command first in command, the server is not coming up and I'm only seeing the output from background script.

When I put the flask run command first, the background script is not starting at all.

Is there any proper way to run these two commands on container start up?

Generally you’d run the other command in a second container. Is there any specific reason it must be in the same container? — David Maze, Oct 03 '19 at 15:05
As per the requirement that I'm working on, they have to be on a same container. — Underoos, Oct 03 '19 at 16:24

score 3 · Accepted Answer · answered Oct 03 '19 at 13:54

3

create a script.sh

#!/bin/bash
python app/workload/services/queue_services.py > qlog.txt &
flask run --host=0.0.0.0 --port 5000

and set it as your command

answered Oct 03 '19 at 13:54

LinPy

score 0 · Answer 2 · edited Oct 03 '19 at 15:00

0

Try Adding

CMD ["gunicorn", "--bind=0.0.0.0:5000", "--workers=1", "wsgi"]

in DockerFile

edited Oct 03 '19 at 15:00

Stefano

answered Oct 03 '19 at 14:02

sandeep

score 0 · Answer 3 · answered Oct 04 '19 at 10:28

Another approach could be to use a program like supervisord. This way, we can scale it to multiple services without ever modifying the Dockerfile

3 Answers3