How do you start a Docker-ubuntu container into bash?

Question

The answers from this question do not work.

The docker container always exits before I can attach or won\'t accept the -t flag. I could list al

Answer 1

Here is a very simple Dockerfile with instructions as comments ... launch it to spin up a running container you can exec login to

FROM ubuntu:20.04

ENV TERM linux
ENV DEBIAN_FRONTEND noninteractive

RUN apt-get update
RUN apt-get install -y  

CMD ["/bin/bash"]


# ... save this file as Dockerfile then in same dir issue following
#
# docker build --tag stens_ubuntu .   # creates image stens_ubuntu
#
# docker run -d  stens_ubuntu  sleep infinity # launches container 
#
# docker ps     #   show running containers
#
# 
# ... find CONTAINER ID from above and put into something like this
#
# docker exec -ti $( docker ps | grep stens_ubuntu | cut -d' ' -f1 ) bash   #  login to running container
# docker exec -ti 3cea1993ed28 bash   #  login to running container using sample containerId  
#

A container will exit normally when it has no work to do ... if you give it no work it will exit immediately upon launch for this reason ... typically the last command of your Dockerfile is the execution of some flavor of a server which stays alive due to an internal event loop and in so doing keeps alive its enclosing container ... short of that you can mention a server executable which has been installed into the container as the final parameter of your call to

docker run -d  my-image-name  my-server-executable