docker-image: follow-up concerning internal run-sequence of 'nsx-t-install' image

[maldex]

All tough I still don't get why fly sync can work before fly login, the current image only seems to work on ubuntu hosts. Following up issue #18 and the canceled pr #19, the attached proposal is an overhaul of the current build and run methods.

Essentially: run.sh

• the ENTRYPOINT directive allows for container parameters to be passed into the actual application (note: this behavior differs from CMD directive). The proposed run.sh allows for argument segregation of docker related and application related arguments. Please find a sample in the simplified run.nsx-t-install-er.sh script.
• in short: argument passing has changed into what docker requires and what run.sh requires.
• the original flow has been kept, but 'modularized' into shell functions.
• the fly-related commands have also been rewritten into shell-functions.
• the container (should) automatically detect if it's interactive and present you with a bash.
• shutdown and destruction has been refactored.
• the involved containers should not stay around and cause conflict (using --rm switch and ensuring docker-compose down was called upon graceful container termination)

Dockerfile

• splitup into multiple run statements leverageing the layering during the build.
• unified downloads to wget and added some documentation.

run.nsx-t-install-er.sh

• helper to figure your IP and DNS automagically.

So far i was able to bring the concourse pipeline for nsx-t-install up and running on a Fedora host. cheers

proposed vs recent Signed-off-by: Maldex godlike@gmx.ch

[maldex]

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