RHCSA8 Sample Exam 1

Task 01: Assuming the root user password is lost, and your system is running in multi-user target with no current root session open. Reboot the system into an appropriate target, and reset the root user password to root1234. Log in with root and perform the remaining tasks.

interrupt the boot process, press e to edit the grub config file add rd.break at the end of the Linux kernel line, press ctrl+x to continue the boot process

mount -o remount,rw /sysroot
chroot /sysroot
passwd
enter new pasword twice
touch /.autorelabel
exit
exit

Task 02: Using a manual method (create/modify files by hand), configure a network connection on the primary network device with IP address 192.168.0.241/24, gateway 192.168.0.1, and nameserver 192.168.0.1 (you may use different IP assignments based on your lab environment).

nmcli connection add con-name static-config ifname ens192 type ethernet ip4 192.168.0.241/24 gw4 192.168.0.1 ipv4.dns 192.168.0.1 autoconnect no

Task 03: Using a manual method (modify file by hand), set the system hostname to rhcsa1.example.com and alias rhcsa1. Make sure that the new hostname is reflected in the command prompt.
hostnamectl set-hostname rhcsa1.example.com
echo "192.168.0.241 rhcsa1" >> /etc/hosts -- it's still unclear whether the alias assignment works this way, but it's the best solution that I could find..
su -

Task 04: Set the default boot target to multi-user.

systemctl set-default multi-user.target

Task 05: Set SELinux to permissive mode.

vi /etc/selinux/config
find the line SELINUX=enforcing and change it to SELINUX=permissive

Task 06: Perform a case-insensitive search for all lines in the /usr/share/dict/linux.words file that begin with the pattern “essential”. Redirect the output to /tmp/pattern.txt file. Make sure that empty lines are omitted.

grep -e '^essential' /usr/share/dict/linux.words | grep -v '^$'

Task 07: Change the primary command prompt for the root user to display the hostname, username, and current working directory information in that order. Update the peruser initialization file for permanence.

echo "PS1=\"[\\h@\\u:\\w]\> \"" >> /root/.bashrc

Task 08: Create user accounts called user10, user20, and user30. Set their passwords to Temp1234. Make accounts for user10 and user30 to expire on December 31, 2021.

useradd user10
useradd user20
useradd user30
passwd user10 enter passwd
passwd user20 enter passwd
passwd user30 enter passwd
chage --expiredate "2021-12-31" user10
chage --expiredate "2021-12-30" user30

Task 10: Create a user account called user40 with UID 2929. Set the password to user1234.
useradd user40 -u 2929
passwd user40 enter passwd

Task 11: Create a directory called dir1 under /tmp with ownership and owning group set to root. Configure default ACLs on the directory and give user user10 read, write, and execute permissions.

#!/bin/bash

mkdir /tmp/dir1
chown root:root /tmp/dir1
setfacl -m u:user10:rwX /tmp/dir1
setfacl -m d:u:user10:rwX /tmp/dir1
getfacl /tmp/dir1

Task 12: Attach the RHEL 8 ISO image to the VM and mount it persistently to /mnt/cdrom. Define access to both repositories and confirm.

mkdir /mnt/iso
echo "/rhel-8.3-x86_64-dvd.iso /mnt/iso iso9660 defaults 0 0" >> /etc/fstab
mount -a
vi /etc/yum.repos.d/local.repo

[baseos]
name=baseos repo from the mounted iso file
baseurl=file:///mnt/iso/BaseOS
enabled=1
gpgcheck=0

[appstream]
name=appstream repo from the mounted iso file
baseurl=file:///mnt/iso/AppStream
enabled=1
gpgcheck=0

Task 13: Create a logical volume called lvol1 of size 300MB in vgtest volume group. Mount the Ext4 file system persistently to /mnt/mnt1.

parted /dev/sdb assume we are dealing with gpt partition scheme (parted) mkpart
(parted) name pv1
(parted) file system type xfs
(parted) start 1mb
(parted) end 3gb
(parted) print
1 1MB 3000mb 2999MB pv1 xfs
(parted)set 1 lvm on
1 1MB 3000mb 2999MB pv1 xfs lvm
(parted)q
udevadm settle
pvcreate /dev/sdb1
vgcreate vgtest /dev/sdb1
lvcreate -n lvol1 -L 300m vgtest
mkfs.ext4 /dev/vgtest/lvol1
test blkid /dev/vgtest/lvol1
mkdir /mnt/mnt1
echo "/dev/vgtest/lvol1 /mnt/mnt1 ext4 defaults 0 0" >> /etc/fstab
mount -a
test mount | grep mnt1

Task 14: Change group membership on /mnt/mnt1 to group10. Set read/write/execute permissions on /mnt/mnt1 for group members, and revoke all permissions for public.

chown :group10 /mnt/mnt1
chmod 770 /mnt/mnt1

Task 15: Create a logical volume called lvswap of size 300MB in vgtest volume group. Initialize the logical volume for swap use. Use the UUID and place an entry for persistence.

lvcreate -n lvswap -L 300m vgtest
mkswap /dev/vgtest/lvswap
echo "UUID=xxxx-xxxx-xxxx-xxxx-xxxx swap swap defaults 0 0" >> /etc/fstab
swapon -a
swapon --show

Task 16: Use tar and bzip2 to create a compressed archive of the /etc/sysconfig directory. Store the archive under /tmp as etc.tar.bz2.

tar cvfj /tmp/etc.tar.bz2 /etc/sysconfig
tar tfv /tmp/etc.tar.bz2 #list the archive for the test

Task 17: Create a directory hierarchy /dir1/dir2/dir3/dir3, and apply SELinux contexts for /etc on it recursively.

mkdir -p /dir1/dir2/dir3
ls -dZ /etc check the context of the /etc, it's etc_t
semanage fcontext -a -t etc_t " /dir1(/.*)?"
restorecon -Rv /dir1

Task 18: Enable access to the atd service for user20 and deny for user30.

echo "user30" >> /etc/at.deny
echo "user20" >> /etc/at.allow
systemctl restart atd

Task 19: Add a custom message “This is RHCSA sample exam on $(date) by $LOGNAME” to the /var/log/messages file as the root user. Use regular expression to confirm the message entry to the log file.

logger "This is RHCSA sample exam on $(date) by $LOGNAME"
grep RHCSA /var/log/messages

Task 20: Allow user20 to use sudo without being prompted for their password.

#!/bin/bash

echo "user20 ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/user20
sudo -u user20 sudo cat /boot/efi/EFI/redhat/grub.cfg > /dev/null
if [ $? -eq 0 ]; then
echo user20 has a sudo privileges without password
else
echo error
fi

Task 21: Write a bash shell script that creates three users: user555, user666, user777 with nologin shell and passwords matching their names. The script should also extract names of these three new users from the /etc/passwd and redirect them to /var/tmp/newusers.

#!/bin/bash
for i in {5..7}; do
useradd user$i$i$i #-s /sbin/nologin
echo user$i$i$i:user$i$i$i | chpasswd
done
cut -d : -f 1 /etc/passwd | tail -n 3 > /var/tmp/newusers
echo "Newly added users are: "
cat /var/tmp/newusers