linuxexpert-practice-labs/labs/rhcsa/1-6-standard-permissions/README.md

RHCSA 1.6: Standard permissions

Owners and modes on a file, a directory only its group can use, fixing a whole tree in one command, and finding the directory that blocks access.

Before you start

The lab creates users alice and bob (neither is in wheel), a tree /srv/project whose files and directories have a mix of modes, and /opt/app/conf/app.conf, mode 644, that alice can't read. Write the finding of task 4 to /root/lab-answers/4.

Tasks

1. Create /srv/reports/q3.txt, owned by alice and the group wheel, readable and writable by alice, readable by the group, and with no access for anyone else.
2. Make the directory /srv/reports usable by its group (list, enter, create files) but closed to others.
3. Make every directory under /srv/project mode 755 and every file 644 in one chmod command.
4. Find out why alice can't read /opt/app/conf/app.conf although the file is mode 644. Write the full path of the directory that blocks her to /root/lab-answers/4, then fix it so she can read the file.

Hints

• chown alice:wheel, chmod 640 or chmod u=rw,g=r,o=.
• A directory needs x to be entered and r to be listed: 770. su - bob -c 'ls /srv/reports' should fail.
• chmod -R u=rwX,go=rX: capital X sets execute only on directories (and files that already have it, so check the files too).
• namei -l shows the permissions of every directory on the path.