whiteouts present when extracting images with multiple layers

[mudler]

cos-toolkit version:
0.6.7

Describe the bug
Seems whiteouts are present when using derivative images with multiple layers

To Reproduce
cos-upgrade to an image with layers that are adding/removing the same file

Expected behavior
No whiteouts present

Additional context
Possible regression caused by #509 . A possible workaround would be to set export LUET_PRIVILEGED_EXTRACT=true in the cos config file

[mudler]

@ibuildthecloud which version of cos-installer are you running? It might be just a old one.

I've tried to repro, but it seems it was a problem only when LUET_PRIVILEGED_EXTRACT=true is set, note that was changed since #509.

My test:

FROM alpine

RUN touch foo
RUN rm -rf foo

Pushed as image: quay.io/costoolkit/test-images:wh

❯ sudo luet util unpack quay.io/costoolkit/test-images:wh unpack                                                                                                            
 Luet version 0.17.8-g3402641241fd6459a4c95f6055b98a728c4e2c67 2021-08-11 0135 UTC                                                                                          
                                                                                                                                                                            
        Luet Copyright (C) 2019-2021 Ettore Di Giacinto                                                                                                                     
        This program comes with ABSOLUTELY NO WARRANTY.                                                                                                                     
        This is free software, and you are welcome to redistribute it                                                                                                       
        under certain conditions.                                                                                                                                           
                                                                                                                                                                            
 Downloading quay.io/costoolkit/test-images:wh to /home/ettore/tests/unpack                                                                                                 
 Pulled: sha256:eb357244172dcdc5fb8019b8e9462a4f1db9b0d6e833fd6b2acf82528d0892b1 quay.io/costoolkit/test-images:wh                                                          
 Size: 5.332MiB                                                                                                                                                             
                                                                                                                                                                            
~/tests 11s                                                                                                                                                                 
❯ ls -liah unpack                                                                                                                                                           
total 76K                                                                                                                                                                   
 74847242 drwxr-xr-x 19 ettore users 4.0K Sep  6 10:52 .                                                                                                                    
 73142049 drwxr-xr-x  5 ettore users 4.0K Sep  6 10:32 ..                                                                                                                   
 76286679 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 bin                                                                                                                  
 76286761 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 dev                                                                                                                  
 76943366 drwxr-xr-x 15 root   root  4.0K Aug 27 13:05 etc                                                                                                                  
 82972309 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 home                                                                                                                 
 82972311 drwxr-xr-x  7 root   root  4.0K Aug 27 13:05 lib                                                                                                                  
 83628220 drwxr-xr-x  5 root   root  4.0K Aug 27 13:05 media                                                                                                                
 83889528 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 mnt                                                                                                                  
 84018601 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 opt                                                                                                                  
 84018606 dr-xr-xr-x  2 root   root  4.0K Aug 27 13:05 proc                                                                                                                 
 84150237 drwx------  2 root   root  4.0K Aug 27 13:05 root                                                                                                                 
 84412245 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 run                                                                                                                  
 84412247 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 sbin                                                                                                                 
 98308105 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 srv                                                                                                                  
 98702122 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 sys                                                                                                                  
 98960978 drwxrwxrwt  2 root   root  4.0K Aug 27 13:05 tmp                                                                                                                  
 98960981 drwxr-xr-x  7 root   root  4.0K Aug 27 13:05 usr                                                                                                                  
101191385 drwxr-xr-x 12 root   root  4.0K Aug 27 13:05 var                                                                                                                  

While the bug is present when using the old extraction way, which is based on the containerd snapshotter, but we have it disabled by default already in #509:

❯ sudo -E LUET_PRIVILEGED_EXTRACT=true luet util unpack quay.io/costoolkit/test-images:wh unpack
 Luet version 0.17.8-g3402641241fd6459a4c95f6055b98a728c4e2c67 2021-08-11 0135 UTC
 
        Luet Copyright (C) 2019-2021 Ettore Di Giacinto
        This program comes with ABSOLUTELY NO WARRANTY.
        This is free software, and you are welcome to redistribute it
        under certain conditions.

 Downloading quay.io/costoolkit/test-images:wh to /home/ettore/tests/unpack
 Pulled: sha256:818113230e3d0af5402d93db197743fbda2cae84eaf49eccf5864e67f52cf50c quay.io/costoolkit/test-images:wh
 Size: 2.686MiB

~/tests
❯ ls -liah unpack
total 76K
 74847242 drwxr-xr-x 19 root   root  4.0K Sep  6 10:53 .
 73142049 drwxr-xr-x  5 ettore users 4.0K Sep  6 10:53 ..
 76286679 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 bin
 76286761 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 dev
 76943366 drwxr-xr-x 15 root   root  4.0K Aug 27 13:05 etc
 74847248 -rw-r--r--  1 root   root     0 Sep  6 10:33 foo
 82972309 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 home
 82972311 drwxr-xr-x  7 root   root  4.0K Aug 27 13:05 lib
 83628220 drwxr-xr-x  5 root   root  4.0K Aug 27 13:05 media
 83889528 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 mnt
 84018601 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 opt
 84018606 dr-xr-xr-x  2 root   root  4.0K Aug 27 13:05 proc
 84150237 drwx------  2 root   root  4.0K Aug 27 13:05 root
 84412245 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 run
 84412247 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 sbin
 98308105 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 srv
 98702122 drwxr-xr-x  2 root   root  4.0K Aug 27 13:05 sys
 98960978 drwxrwxrwt  2 root   root  4.0K Aug 27 13:05 tmp
 98960981 drwxr-xr-x  7 root   root  4.0K Aug 27 13:05 usr
101191385 drwxr-xr-x 12 root   root  4.0K Aug 27 13:05 var
 74847321 -rw-------  1 root   root     0 Sep  6 10:33 .wh.foo