Docker bash'ing with find

Question

I am having a hell of a time attempting to get a bash script to work as expected (as it does in a normal bash session) on a Docker run.

The goal is to replace all of the symlinked files within the official java container with their actual file within the JAVA_HOME directory, so everything is contained within the java directory and not outside of it, eg

$JAVA_HOME/jre/lib/security/java.policy <--- is symlinked to ---> /etc/java-7-openjdk/security/java.policy

The end result should be the file located at: $JAVA_HOME/jre/lib/security/java.policy

The setup:

docker run java:7u91 /bin/bash -cxe "find /usr/lib/jvm/**/jre -type l | while read f; do echo $f; cp --remove-destination $(readlink $f) $f; done;"

I had attempted several different methods of effectively this, with xargs and exec all to no avail.

Any suggestions at this point would be appreciated.

Answer 1

It looks like this is what is happening: $(readlink $f) is not returning anything on the files that are not symbolic links (only works on symbolic links). Therefore, that expression is essentially nothing/empty.

So, only the $f is returning a value. Therefore, if the expression was evaluated, it would print cp --remove-destination VALUE_OF_$F; , and the $f would look like it was the first parameter of the cp command, with no second parameter present. That is why the 'destination' is missing.

Also, you need to consider the fact that putting your command inside of double quotes like that is presenting a problem. The variables will be parsed on the host rather than in the docker container. Replace the double quotes with single quotes to prevent that from happening.