Description of problem:

The rootfs of 4.2 ISO is having a dangling symlink on the "/etc/redhat-access-insights/machine-id" file.

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mount usr/share/redhat-virtualization-host/image/redhat-virtualization-host-4.2-20181026.0.el7_6.squashfs.img squashfs

mount squashfs/LiveOS/rootfs.img rootfs

ls -l rootfs/etc/redhat-access-insights/machine-id 
lrwxrwxrwx. 1 root root 31 Oct 26 12:15 rootfs/etc/redhat-access-insights/machine-id -> /etc/insights-client/machine-id

ls -l rootfs/etc/insights-client/machine-id
ls: cannot access 'rootfs/etc/insights-client/machine-id': No such file or directory
===

From 7.5, redhat-access-insights is being deprecated and has been replaced with insights-client. Refer https://access.redhat.com/articles/3405441. So the 4.2 ISO will be having insights-client and 4.1 is having redhat-access-insights.  

The 4.1 is not having this symlink because it's having redhat-access-insights package.

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ls -l /etc/redhat-access-insights/machine-id
-rw-r--r--. 1 root root 36 Dec  7  2017 /etc/redhat-access-insights/machine-id
===

Now when we do the upgrade, the imgbased will try to copy the /etc/redhat-access-insights/machine-id from 4.1 to 4.2 and it will fail with the error below since destination file is a dangling symlink.

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2018-11-14 06:56:45,467 [DEBUG] (migrate_etc) Calling binary: (['mount', u'/dev/rhvh/rhvh-4.1-0.20170417.0+1', u'/tmp/mnt.uinB1'],) {}
2018-11-14 06:56:45,310 [DEBUG] (migrate_etc) Calling binary: (['mount', u'/dev/rhvh/rhvh-4.2.7.3-0.20181026.0+1', u'/tmp/mnt.avsbD'],) {}


2018-11-14 06:57:12,730 [DEBUG] (migrate_etc) Calling: (['cp', '-a', '-r', u'/tmp/mnt.uinB1///etc/redhat-access-insights/machine-id', u'/tmp/mnt.avsbD///etc/redhat-access-insights/machine-id'],) {'close_fds': True, 'stderr': -2}

2018-11-14 06:57:12,734 [DEBUG] (migrate_etc) Exception! cp: not writing through dangling symlink '/tmp/mnt.avsbD///etc/redhat-access-insights/machine-id'

===


Version-Release number of selected component (if applicable):

imgbased-1.0.29


How reproducible:

100%

Steps to Reproduce:

1. In a 4.1 RHV-H, register to insights using command "redhat-access-insights --register". This will generate file "/etc/redhat-access-insights/machine-id" file.

2. Change the date of machine-id file.

touch -d 20171207 /etc/redhat-access-insights/machine-id

This is required to reproduce the issue or else rsync will correct the symlink when it does copying from 4.1 layer to 4.2 layer as we do rsync with --update and the destination machine-id will be having an older timestamp compared to the file in source 4.1 layer.   

I set the same date as customer machine-id.

3. Do the update. It will fail with the error below.

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2018-11-14 06:57:13,722 [DEBUG] (MainThread) Traceback (most recent call last):
  File "/tmp/tmp.lwoc2tT3YW/usr/lib/python2.7/site-packages/imgbased/utils.py", line 1521, in thread_group_handler
    t.join_with_exceptions()
  File "/tmp/tmp.lwoc2tT3YW/usr/lib/python2.7/site-packages/imgbased/utils.py", line 1513, in join_with_exceptions
    raise exc[1]
CalledProcessError: Command '['cp', '-a', '-r', u'/tmp/mnt.uinB1///etc/redhat-access-insights/machine-id', u'/tmp/mnt.avsbD///etc/redhat-access-insights/machine-id']' returned non-zero exit status 1

2018-11-14 06:57:13,722 [ERROR] (MainThread) Failed to migrate etc
Traceback (most recent call last):
  File "/tmp/tmp.lwoc2tT3YW/usr/lib/python2.7/site-packages/imgbased/plugins/osupdater.py", line 130, in on_new_layer
    thread_group_handler(threads)
  File "/tmp/tmp.lwoc2tT3YW/usr/lib/python2.7/site-packages/imgbased/utils.py", line 1524, in thread_group_handler
    sys.exit(1)
SystemExit: 1
===


Actual results:

RHV-H upgrade from 4.1 to 4.2 is failing with error "not writing through dangling symlink" if the server is registered to insight

Expected results:

Upgrade should work.

Additional info: