CODEWITHSUNDEEP
bashdocker
Ralff
Ralff

Reputation: 491

How to run a bash terminal in a Docker container along with additional commands?

To run a bash terminal in a Docker container I can run the following:

$ docker exec -it <container> /bin/bash

However, I want to execute a command in the container automatically. For example, if I want to open a bash terminal in the container and create a file I would expect to run something like:

docker exec -it <container> /bin/bash -c "touch foo.txt"

However, this doesn't work... Is there a simple way to achieve this? Of course, I could type the command after opening the container, but I want to open a bash terminal and run a command at the same time.

Upvotes: 1

Views: 2429

Answers (4)

Philippe
Philippe

Reputation: 26377

You can run your touch command and then spawn another shell :

docker exec -it <container> /bin/bash -c "touch foo.txt; exec bash"

Upvotes: 4

jordanvrtanoski
jordanvrtanoski

Reputation: 5517

Works perfectly fine for me

~# docker run -tid --rm --name test ubuntu:20.04
~# docker exec -it test /bin/bash -c "touch /foo.txt"
~# docker exec -it test /bin/bash
root@b6b0efbb13be:/# ls -ltr foo.txt
-rw-r--r-- 1 root root 0 Mar  7 05:35 foo.txt

Upvotes: 2

Saeed
Saeed

Reputation: 4115

When you run docker exec -it <container> /bin/bash -c "touch foo.txt", container sends 0 exit code so that it means the task is done and you'll be returned to your host.

When you run docker exec -it <container /bin/bash, bash shell is not terminated until you explicitly type exit or use CTRL+D in bash environment. bash is continuously running.

This is why when you run the second command, it goes to bash, runs your command (touches) and then exits.

Upvotes: 1

gilito
gilito

Reputation: 309

Easy solution:

docker exec -it <container> touch foo.txt

You can verify

docker exec -it <container> ls

This was tested with alpine image.

Remember that in docker images there is a entrypoint and a command. Now we are editing the command of the default entrypoint for alpine, via docker exec

It depends of the entrypoint if env variablers are load or not, $PATH ..., so other images maybe you need to write /bin/touch or /usr/bin/ls

Good luck!

Upvotes: 1

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