Docker-compose up does not start a container

Question

Dockerfile:

FROM shawnzhu/ruby-nodejs:0.12.7

RUN \
    apt-get install git \   
    && npm install -g bower gulp grunt \
    gem install sass

RUN useradd -ms /bin/bash devel

# Deal with ssh
COPY ssh_keys/id_rsa /devel/.ssh/id_rsa
COPY ssh_keys/id_rsa.pub /devel/.ssh/id_rsa.pub
RUN echo "IdentityFile /devel/.ssh/id_rsa" > /devel/.ssh/config

# set root password
RUN echo 'root:password' | chpasswd

# Add gitconfig
COPY .gitconfig /devel/.gitconfig

USER devel

WORKDIR /var/www/

EXPOSE 80

docker-compose.yml file:

nodejs:
  build: .
  ports:
    - "8001:80"
    - "3000:3000"
  volumes:
    - ~/Web/docker/nodejs/www:/var/www

Commands:

$ docker-compose build nodejs

$ docker images

REPOSITORY             TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
nodejs_nodejs          latest              aece5fb27134        2 minutes ago       596.5 MB
shawnzhu/ruby-nodejs   0.12.7              bbd5b568b88f        5 months ago        547.5 MB

$ docker-compose up -d nodejs

Creating nodejs_nodejs_1

$ docker ps

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

$ docker ps --all

CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS                          PORTS               NAMES
c24c6d0e756b        nodejs_nodejs       "/bin/bash"         About a minute ago   Exited (0) About a minute ago                       nodejs_nodejs_1

As you can see the docker-compose up -d should have created a container and run it on the background, but it didn't. Instead it exited with code 0.

Answer 1

If your Dockerfile doesn't do anything (for example a webserver to listen on port 80), it will be discarded as soon as it finishes running the instructions. Because Docker containers should be "ephemeral".

If you just want to start a container and interact with it via terminal, don't use docker-compose up -d, use the following instead:

docker run -it --entrypoint=/bin/bash [your_image_id]

This will start your container and run /bin/bash, the -it helps you keep the terminal session to interact with the container. When you are done doing your works, press Ctrl-D to exit.