EX200 Timed Practice Test 5 — 10 Questions

Question 1

A server's firewall is managed by firewalld. The admin adds a rule to allow HTTPS traffic to the public zone, but clients still cannot connect. What is the most likely cause?

Accepted Answer

The rule was added with --permanent but firewall-cmd --reload was not run.. Option A is correct because when a rule is added with the `--permanent` flag in firewalld, it is written to the configuration files but not applied to the runtime firewall. Until `firewall-cmd --reload` is executed, the runtime configuration remains unchanged, so the new rule allowing HTTPS traffic is not active. Clients cannot connect because the firewall is still blocking HTTPS based on the old runtime rules.

Answer

The rule must be added as a rich rule, not a simple service.

Answer

The default zone is not set to public.

Answer

firewalld is just a wrapper for iptables, so iptables rules must be cleared.

Question 2

Which TWO commands can be used to display SELinux contexts of files? (Choose two.)

Accepted Answer

stat -c %C. The `stat -c %C` command displays the SELinux security context of a file by using the `%C` format specifier, which outputs the security context string. The `ls -Z` command also shows SELinux contexts for files in a directory listing, with the `-Z` flag specifically requesting security context information. Both commands are standard tools for viewing SELinux labels on files.

Answer

chcon -l

Answer

id -Z

Answer

getenforce

Question 3

A developer reports that a container running a custom web application is failing to start on a Red Hat Enterprise Linux 8 host. The container image is built from a Dockerfile that uses 'EXPOSE 8080'. The host firewall is enabled. Which action is most likely required to allow external access to the application?

Accepted Answer

Start the container with the '-p 8080:8080' option to publish the port.. The container image's EXPOSE 8080 instruction is metadata that documents the intended port but does not actually publish it. To make the container's port 8080 accessible from the host's network, you must use the '-p 8080:8080' option when starting the container with 'podman run' or 'docker run'. This creates a port mapping from the host's port 8080 to the container's port 8080, allowing external traffic to reach the application.

Answer

Open port 8080 in the host firewall using firewall-cmd.

Answer

Disable the host firewall to allow all incoming traffic.

Answer

Ensure the container image includes an EXPOSE instruction for port 8080.

Question 4

Which THREE actions are required to enable a non-root user to run containers using Podman on Red Hat Enterprise Linux 8?

Accepted Answer

Ensure the user has a running systemd user instance (loginctl enable-linger).. Option A is correct because `loginctl enable-linger` ensures that the user's systemd user instance starts at boot and remains running after the user logs out. This is required for Podman to manage containers using systemd user services, such as auto-starting containers with `podman generate systemd`.

Answer

Add the user to the 'docker' group to access the Docker socket.

Answer

Grant the user sudo privileges to run podman commands.

Question 5

A container running a database service needs to persist data across restarts. The administrator decides to use a named volume. Which command creates a named volume and mounts it correctly?

Accepted Answer

podman volume create dbdata && podman run -v dbdata:/var/lib/mysql mydb. Option B is correct because it first creates a named volume with `podman volume create dbdata`, then mounts that named volume to the container's `/var/lib/mysql` directory using the `-v` flag. Named volumes are managed by Podman and persist data independently of the container lifecycle, ensuring data survives container restarts or removal.

Answer

podman run -v /var/lib/mysql:/var/lib/mysql mydb

Answer

podman run --mount type=bind,src=dbdata,dst=/var/lib/mysql mydb

Answer

podman run --mount type=tmpfs,dst=/var/lib/mysql mydb

Question 6

Which TWO statements are true regarding container images and containers in Podman?

Accepted Answer

A container is a running or stopped instance of an image with a writable layer.. Option B is correct because a container in Podman is an instantiation of an image that adds a writable layer on top of the image's read-only layers. This writable layer persists changes made during the container's runtime, even after the container is stopped, unless explicitly removed.

Answer

A container can only be created from an image that is stored locally.

Answer

When a container is stopped, its writable layer is automatically removed.

Answer

A container image must be built using a Dockerfile.

Question 7

A system administrator needs to create a shell script that checks if the user 'jdoe' exists in the system and, if not, creates the user with a home directory. The script should also verify that the creation was successful. Which of the following script snippets correctly implements this logic?

Accepted Answer

if id 'jdoe' &>/dev/null; then echo 'Exists'; else useradd -m 'jdoe' && echo 'Created' || echo 'Failed'; fi. Option B is correct because it uses `id` to check for the user's existence (redirecting output to /dev/null to suppress messages), then uses `useradd -m` to create the user with a home directory. The `&&` and `||` operators ensure that success or failure of the creation is explicitly reported, fulfilling the requirement to verify successful creation.

Answer

if grep -q '^jdoe:' /etc/passwd; then echo 'Exists'; else useradd 'jdoe' && echo 'Created'; fi

Answer

if ! id 'jdoe' &>/dev/null; then useradd -m 'jdoe'; else echo 'Exists'; fi

Answer

[ -z $(id 'jdoe' 2>/dev/null) ] && useradd -m 'jdoe' && echo 'Created'

Question 8

Refer to the exhibit. A junior admin runs this script as root, but it always prints 'httpd is running' even when httpd is stopped. What is the most likely cause?

Accepted Answer

The script uses the test command `[` instead of directly using the command as the condition, causing the condition to always be true.. Option D is correct because when a command is used as a condition inside `[ ]`, the `test` builtin evaluates the exit status of the command inside the brackets, not the command itself. In this script, `[ systemctl is-active httpd ]` always returns true (exit code 0) because `[` treats the string "systemctl" as a non-empty string, which is always true. The correct syntax is to use the command directly as the condition: `if systemctl is-active httpd; then`.

Answer

The script is not executable and is run with `sh script.sh`, causing the shebang to be ignored.

Answer

The variable SERVICE is misspelled as "HTTPD" in the condition.

Answer

The `systemctl` command requires root privileges, and the script is run as a non-root user.

Question 9

A system administrator needs to add a new 10GB disk to an existing volume group 'vgdata' to extend logical volumes. Which of the following is the correct sequence of commands?

Accepted Answer

pvcreate /dev/sdb, vgextend vgdata /dev/sdb, lvextend. Option A is correct because the proper sequence to add a new disk to an existing volume group is: first create a physical volume with `pvcreate /dev/sdb`, then extend the volume group with `vgextend vgdata /dev/sdb`, and finally extend the logical volume with `lvextend`. This order ensures the disk is initialized as a PV before it can be added to the VG, and the VG must have the new PV before the LV can be extended.

Answer

vgextend vgdata /dev/sdb, pvcreate /dev/sdb, lvextend

Answer

pvcreate /dev/sdb, lvextend, vgextend vgdata /dev/sdb

Answer

lvextend, vgextend vgdata /dev/sdb, pvcreate /dev/sdb

Question 10

A system administrator needs to find all files in /var/log that have been modified in the last 2 hours. Which command should be used?

Accepted Answer

find /var/log -mmin -120. Option A is correct because the `find` command with `-mmin -120` searches for files whose data was modified (changed content) within the last 120 minutes. This directly matches the requirement to find files modified in the last 2 hours in /var/log.

Answer

find /var/log -amin -120

Answer

find /var/log -mtime -0.08

Answer

find /var/log -cmin -120