How to run the python application and postgres in one docker container?

问题

I have a python application that interacts with the postgresql database and i need to run it all in one docker container. I get a connection error when running the container:

  ...

  File "/usr/lib/python3.6/asyncio/tasks.py", line 358, in wait_for
    return fut.result()
  File "/usr/lib/python3.6/asyncio/base_events.py", line 787, in create_connection
    ', '.join(str(exc) for exc in exceptions)))
OSError: Multiple exceptions: [Errno 111] Connect call failed ('::1', 5432), [Errno 111] Connect call failed ('127.0.0.1', 5432)

My Dockerfile:

FROM postgres:10.0-alpine
RUN apk add --update --no-cache g++ alpine-sdk
RUN apk --no-cache add python3-dev
RUN apk add --no-cache python3 && \
    python3 -m ensurepip && \
    rm -r /usr/lib/python*/ensurepip && \
    pip3 install --upgrade pip setuptools && \
    if [ ! -e /usr/bin/pip ]; then ln -s pip3 /usr/bin/pip ; fi && \
    if [[ ! -e /usr/bin/python ]]; then ln -sf /usr/bin/python3 /usr/bin/python; fi && \
    rm -r /root/.cache    
ADD app /app/   
RUN chmod -R 777 /app 
WORKDIR /app
ADD requirements.txt requirements.txt
RUN pip3 install -r requirements.txt
USER postgres
RUN chmod 0700 /var/lib/postgresql/data &&\
    initdb /var/lib/postgresql/data &&\
    echo "host all  all    0.0.0.0/0  md5" >> /var/lib/postgresql/data/pg_hba.conf &&\
    echo "listen_addresses='*'" >> /var/lib/postgresql/data/postgresql.conf &&\
    pg_ctl start &&\
    psql --command "ALTER USER postgres WITH ENCRYPTED PASSWORD 'postgres';"
EXPOSE 5432
EXPOSE 80
CMD ["python3", "main.py"]

回答1:

Although this is not recommended, it's doable. The problem is pg_ctl in RUN instruction is executed at build time, not in the container. You need to run it with CMD.

You can have a script like

pg_ctl start
psql --command "ALTER USER postgres WITH ENCRYPTED PASSWORD 'postgres';"
python3 main.py

COPY the script in the image and at the end of the dockerfile, `CMD ["./script.sh"]

回答2:

@Anton, it is not recommended to run multiple processes inside a docker container. Have a look at this link https://docs.docker.com/config/containers/multi-service_container/ it will explain more and demonstrate a manner to accomplish this. You probably are aware, but your container will be running the postgresql instance and have the data in it, so if you ever re-create the container, you will lose any data in that container.

来源：https://stackoverflow.com/questions/54225387/how-to-run-the-python-application-and-postgres-in-one-docker-container

标签

postgresql

Docker