docker container volumes from directory access in CMD instruction

Question

docker container volumes from directory access in CMD instruction

$ sudo docker run -d --name ext -v /external busybox /bin/sh

and

run.sh

#!/bin/bash

if [[ -f "/external" ]]
then
    echo 'success!'
else
    echo 'Sorry, I can't find /external...'
fi

and

Dockerfile

FROM ubuntu:14.04

MAINTAINER newbie

ADD run.sh /run.sh

RUN chmod +x /run.sh

CMD ["bash", "/run.sh"]

and

$ sudo docker build -t app .

and

$ sudo docker run -d --volumes-from ext app ac57afb95f923eeffd28e7d9d9cb76cb1b7699ebd

So

$ sudo docker logs ac57afb95f923eeffd28e7d9d9cb76cb1b7699ebd Sorry, I can't find /external...

My question is,

How can I access /external directory in run.sh in CMD instruction

impossible?

Thank you~

Answer 1

modify your run.sh

-f is check for file exists. in this case use -d check for directory exists.

Check if a directory exists in a shell script

futhermore if you want make only volume container, need not add -d, /bin/sh volume container run command change like this

$ sudo docker run --name ext -v /external busybox