I created a Dockerfile like below:
From alpine:latest
WORKDIR /
COPY ./init.sh .
CMD ["/bin/sh", "./init.sh"]
and a script file init.sh like below:
#!/bin/sh
mkdir -p mount_point
echo hello > ./mount_point/hello.txt
and I built an image using these:
docker build . -t test_build
and ran it as
docker container run --rm --name test_run -it test_build sh
where there are only two above files in the folder.
In the container, I can find the init.sh file with x (executable) as is in the host.
However, there is no folder mount_point which should be created by
CMD ["bin/sh", "./init.sh"]
Note that, when I run any of the below in the container, it successfully creates mount_point as I expected
sh init.sh
or
/bin/sh init.sh
and
sh -c ./init.sh
Could you tell me where I made mistakes?
When you do
docker container run --rm --name test_run -it test_build sh
the sh at the end overrides the CMD definition in the image and the CMD isn't run.
To verify that your script works, your can change the script to something like this
#!/bin/sh
echo Hello from the script!
mkdir -p mount_point
echo hello > ./mount_point/hello.txt
ls -al ./mount_point
Then run the image without the sh and you should see the 'Hello' message and the directory listing from the ./mount_point directory.
docker container run --rm --name test_run test_build