Remove the os.conf creation in the rear.spec file

[gdha]

Remove the os.conf creation in the rear.spec file and fixed in function SetOSVendorAndVersion the proper detection of RedHatEnterpriseServer. Added new script usr/share/rear/init/default/005_verify_os_conf.sh to create the os.conf if it did not exist yet - issue #1639

[jsmeix]

From plain looking at the code
it looks good to me.

[jsmeix]

@gdha
I did not have a closer look how those things work
but I wonder why os.conf needs to be created at all
during "rear WORKFLOW" runtime?
I.e. I wonder why it is not sufficient to only rely
on the SetOSVendorAndVersion() function
during "rear WORKFLOW" runtime?

[gdha]

@jsmeix os.conf is important during the recover phase as we cannot trust that the SetOSVendorAndVersion() function will work properly.

[jsmeix]

Yes, but why is /etc/rear/os.conf autocreated in the original sytem?

Why not only autocreate a $ROOTFS_DIR/etc/rear/os.conf in the recovery system
e.g. in the same way as $ROOTFS_DIR/etc/rear-release gets autocreated by
build/default/970_add_rear_release.sh ?

In general I do not like it when any "rear WORKFOLW" automatically
changes the original system without an explicit user request.
I think in general the original system should be sacrosanct - except there is
really a very good reason to automatically change the original system.

[gdha]

@jsmeix I prefer to have the discussion in #1639 if that is ok for you?

[jsmeix]

@gdha
of course you are right.
This pull request is done and further things should
happen in #1639

[schlomo]

@gdha this is old stuff, but I have a very important question: What needs the /etc/rear/os.conf file on the original system? Wouldn't it be enough to only write that to the rescue system instead?

The reason I'm asking are two problems I encounter:

1. the file will never change, even if the OS is upgraded to a newer version
2. the file is created in the source tree if I run ReaR from checkout, and it stays there forever even if I try ReaR on a different VM

So I'd like to find out if I can move it to the rescue system only. Or maybe we actually don't need it any more because /etc/os-release is now the de-facto standard in any case?

[jsmeix]

See also
#2954 (comment)