When I ran the original I got the following error:
Step 3 : RUN chmod +x /tmp/bootstrap.sh && /tmp/bootstrap.sh
---> Running in 62f54b7a5e6d
/bin/sh: 1: /tmp/bootstrap.sh: Text file busy
Splitting the two commands up seems to give the text file enough time to
finish up. I suppose a slight sleep could also be added inbetween the
two commands if one was worried about creating too many images.
If the mounted data directory on the host is owned by root, the znc user
within the container would fail to write any settings to disk.
Hence this changes ownership of the data directory to the znc user (Uid:
1000) and znc group (Gid: 1000) from within the container.
