FROM image:tag
MAINTAINER Maintainer Name <maintainer@email.address>

# copy files from the build-host into the container's FS
COPY hostfile containerfile

# since each RUN directive results in the creation of a new FS layer, they are often combined together
RUN  cmd_1 && cmd_2 && cmd_3 && ...

# specifies the container's default entry point; in order to handle CL arguments, a script is often used
# which might have the form:
#   #!/bin/bash
#   if [ $# -eq 0 ]; then
#     # default action(s) to be invoked in the absence of CL args
#   else
#     # process the args
#   fi
ENTRYPOINT ["/path/to/entry_cmd"]