Build support for CentOS and Docker

[rdimitrov]

Description

For the time being, the OAI project can be built only on RHEL using Podman.

The following PR aims to add support for CentOS as a base OS image and Docker as a container engine.

This is the status so far -

1. Everything but MME is building successfully.
2. Although the images are building okay, it's still not clear if they also work as expected.

In that sense, it'd be really helpful if someone can assist with that! 👍

Motivation and Context

How Has This Been Tested?

• Covered by existing integration testing
• Added integration testing to cover
• Tested locally
• Have not tested

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[kaltenbe]

Dear authors,
thanks for this pull request. I am happy to see that VMware took an interest in this. It might be worth also starting a discussion between Eurecom, RedHat and VMware on how to possibly collaborate on this in the future. Let us know if you are availiable for such a call.
We shall definitely merge in this pull request, but we need to figure out a few details before. I have seen that you have added a VMware copyright plus the apache header in the new files whereas we haven't done this for any of the other files. So let us check internally if we should do this before.
Florian.

[rdimitrov]

@kaltenbe: Thank you for your feedback! I'd be glad to assist, so we can move this forward 👍

Also, I'd be happy if there's someone willing to help with resolving the failure to build the MME image and possibly help to verify that the images are built okay and run as expected.