如何在 Docker 容器中获取交互式 bash shell

Question

I'm trying to connect to a running container or start a new container in interactive mode with the bash shell -- not the sh shell. I want to run:

docker exec -it <container_name> /bin/bash

or

docker run -it <container_name> <image_name>

or

docker run -it <container_name> <image_name> /bin/bash

and get an interactive bash shell.

What I've tried so far:

Perthis post I've tried

Adding this to my Dockerfile

SHELL ["/bin/bash", "-c"]

Adding this to my Dockerfile

RUN ["/bin/bash", "-c", "echo I am now using bash!"]

But every time I try to run a container in interactive mode ( docker run -it or attach to a running container ( docker exec -it ), I land in the sh shell.

How can I get an interactive bash shell that is running inside a docker container?

Update: Minimal working Dockerfile

FROM ubuntu

SHELL ["/bin/bash", "-c"]

Answer 1

You are in fact running an interactive bash with commands like:

docker container run -it ubuntu /bin/bash

When you run bash in a docker container, that shell is in a container. So it won't have the command history from outside of the container, that history is maintained on the host filesystem. It also won't have your prompt, the PS1 variable is not automatically exported into the container's environment. And it won't have your .bashrc configuration from your host, since that isn't inside the container. Instead you get a bash shell that is out of the box from a minimal ubuntu host.