Run shell script on docker from shared volume

Question

I have a docker container that has a shared volume with the host. The volume mounts in the root home folder. In that folder, I have a shell script I want to run once the container is up and running.

I was using this command:

docker exec -i localserver_web_1 sh /root/scripts/define_applications.sh

but I'm getting this response:

sh: 0: Can't open /root/scripts/define_applications.sh

The script is working fine when I run it from inside the container. It says it's in /root/scripts/. I have permissions set at 777. What could I be doing wrong?

Answer 1

Just to be sure, try and exec as root, with a tty, in a command shell:

docker exec -it -u root localserver_web_1 sh -c '/root/scripts/define_applications.sh'

If it does not work, check at least its presence and content through docker exec:

docker exec -it -u root localserver_web_1 sh -c 'ls -alrt /root/scripts'
docker exec -it -u root localserver_web_1 sh -c 'cat /root/scripts/define_applications.sh'

Also inspect the image to check its ENTRYPOINT (similar to the check for its CMD):

docker inspect --format='{{.Config.Entrypoint}}' <image:tag>

The OP Jon Schwartz confirms in the comments:

this was a pebkac error.
The script is actually called define-applications.sh, not define_applications.sh.
The cat line showed me my issue. When it could see the script through ls, I knew it should be able to get to it. When it couldn't cat out, I realized what happened.