Shrink XFS partition, simply possible ?

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My colleague asking me how to resize/shrink his CentOs 7 /home partition which is 240 GB to 160 GB and then allocate the remaining free space to / (root). Well, actually we can't directly shrink XFS therefore what we can do is backup all the data on /home, delete it and then recreate the /home, here is what todo :

1. Backup the contents of /home

tar -czvf /data/home.tgz -C /home .

2. Test Backup

tar -tvf /data/home.tgz

3. Unmount home

umount /dev/mapper/cl-home

4. Remove the home logical volume

lvremove /dev/mapper/cl-home

5. Recreate logical volume for /home, format and mount it

lvcreate -L 160GB -n home cl

mkfs.xfs /dev/mapper/cl-home

mount /dev/mapper/cl-home /home

6. Extend /root 

lvextend -r -l +100%FREE /dev/mapper/cl-root

7. Restore /home

tar -xzvf /data/home.tgz -C /home

8. Check /etc/fstab for any mapping of /home volume and ensure the file system type.

cat /etc/fstab

10. Ensure things already on their places.

$ lvdisplay

$ fdisk -l

$ mount -l 

$ df -h 

 

 

 

 

        

Walkthrough WebGoat Assignment Crypto Basics #8

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Walkthrough WebGoat Assignment Crypto Basics #8 :

1. First run the docker as requested : docker run -d webgoat/assignments:findthesecret
2. Hints is to escalate using su - , what about BF ing su ?, but we go arround the other way, what we do is escalating user in docker to root, here is what we need to do :

           a) Copy /etc/passwd which contain UID & GID from Container to localsystem.

                $ docker cp Container-ID:/etc/passwd test.passwd

           b) Check test.passwd.

                $ cat test.passwd

root:x:0:0:root:/root:/bin/bash

daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin

bin:x:2:2:bin:/bin:/usr/sbin/nologin

sys:x:3:3:sys:/dev:/usr/sbin/nologin

sync:x:4:65534:sync:/bin:/bin/sync

games:x:5:60:games:/usr/games:/usr/sbin/nologin

man:x:6:12:man:/var/cache/man:/usr/sbin/nologin

lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin

mail:x:8:8:mail:/var/mail:/usr/sbin/nologin

news:x:9:9:news:/var/spool/news:/usr/sbin/nologin

uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin

proxy:x:13:13:proxy:/bin:/usr/sbin/nologin

www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin

backup:x:34:34:backup:/var/backups:/usr/sbin/nologin

list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin

irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin

gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin

nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin

_apt:x:100:65534::/nonexistent:/bin/false

webgoat:x:1000:1000::/home/webgoat: 

 

           c) Edit test.passwd, change webgoat UID & GID from previous 1000:1000 to 0:0.

                    root:x:0:0:root:/root:/bin/bash

daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin

bin:x:2:2:bin:/bin:/usr/sbin/nologin

sys:x:3:3:sys:/dev:/usr/sbin/nologin

sync:x:4:65534:sync:/bin:/bin/sync

games:x:5:60:games:/usr/games:/usr/sbin/nologin

man:x:6:12:man:/var/cache/man:/usr/sbin/nologin

lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin

mail:x:8:8:mail:/var/mail:/usr/sbin/nologin

news:x:9:9:news:/var/spool/news:/usr/sbin/nologin

uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin

proxy:x:13:13:proxy:/bin:/usr/sbin/nologin

www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin

backup:x:34:34:backup:/var/backups:/usr/sbin/nologin

list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin

irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin

gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin

nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin

_apt:x:100:65534::/nonexistent:/bin/false

webgoat:x:0:0::/home/webgoat:

           c) Copy edited test.passwd from localsystem to Container.

                $ docker cp test.passwd Container-ID:/etc/passwd 

           d) Access to Container.

                $ docker exec -it Container-ID /bin/bash

           e) Goto /root folder, and find the secret file (default_secret), and check it.

root@42284f82e8ff:/# cd /root/

root@42284f82e8ff:~# ls

default_secret 

root@42284f82e8ff:~# cat default_secret

ThisIsMySecretPassw0rdF0rY0u 

           f) Run decryption against  given secret to default_secret file. 

root@42284f82e8ff:~# echo "U2FsdGVkX199jgh5oANElFdtCxIEvdEvciLi+v+5loE+VCuy6Ii0b+5byb5DXp32RPmT02Ek1pf55ctQN+DHbwCPiVRfFQamDmbHBUpD7as=" | openssl enc -aes-256-cbc -d -a -kfile default_secret  

Leaving passwords in docker images is not so secure

What is the unencrypted message : Leaving passwords in docker images is not so secure

and what is the name of the file that stored the password :  default_secret