Docker multiple entrypoints

Question

Say I have the following Dockerfile:

FROM ubuntu

RUN apt-get update
RUN apt-get install -y apache2
RUN apt-get install -y mongod #pretend this exists

EXPOS         


        

Answer 1

As Jared Markell said, if you wan to launch several processes in a docker container, you have to use supervisor. You will have to configure supervisor to tell him to launch your different processes.

I wrote about this in this blog post, but you have a really nice article here detailing how and why using supervisor in Docker.

Basically, you will want to do something like:

FROM ubuntu

RUN apt-get update
RUN apt-get install -y apache2
RUN apt-get install -y mongod #pretend this exists
RUN apt-get install -y supervisor # Installing supervisord

ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf 

EXPOSE 80

ENTRYPOINT ["/usr/bin/supervisord"]

And add a configuration a file supervisord.conf

[supervisord]
nodaemon=true

[program:mongodb]
command=/etc/mongod/mongo #To adapt, I don't know how to launch your mongodb process

[program:apache2]
command=/usr/sbin/apache2 -DFOREGROUND

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EDIT: As this answer has received quite lot of upvotes, I want to precise as a warning that using Supervisor is not considered as a best practice to run several jobs. Instead, you may be interested in creating several containers for your different processes and managing them through docker compose. In a nutshell, Docker Compose allows you to define in one file all the containers needed for your app and launch them in one single command.