Automation, Orchestration, and Scripting practice questions

ls -l /var/log/*.log | awk '$5>100 {print $NF}'

Why it fails: This works for some cases but may fail with spaces in filenames or if ls output changes.

for f in /var/log/*.log; do if [ -s $f -a $(stat -c%s $f) -gt 100 ]; then echo $f; fi; done

Why it fails: -s checks if file is non-empty, not size; -gt compares numbers but stat output may cause issues.

for f in /var/log/*.log; do if [ $f -gt 100k ]; then echo $f; fi; done

Why it fails: The test command cannot compare file sizes directly; -gt is for integer comparison.

docker run -v /data:/mnt/data:bind ubuntu

Why it fails: The `-v` flag with `:bind` is syntactically invalid; Docker does not recognize `:bind` as a suffix. The correct syntax for bind mounts with `-v` is just a path pair, e.g., `-v /data:/mnt/data`.

docker run -v /data:/mnt/data ubuntu

Why it fails: Although the `-v` flag with an absolute source path does create a bind mount, the `--mount` syntax with explicit `type=bind` is the recommended and unambiguous method. The `-v` flag is considered legacy and can be confusing, especially when the source path is not absolute.

docker run --mount type=volume,source=/data,target=/mnt/data ubuntu

Why it fails: `type=volume` creates a Docker volume, not a bind mount. A bind mount maps a host directory directly, while a volume is managed by Docker.

podman run -rm -d -p 8080:80 nginx

Why it fails: Incorrect. This command maps host port 8080 to container port 80 (reverse of required) and uses `-rm` instead of `--rm`.

podman run --remove -d -p 80:8080 nginx

Why it fails: Incorrect. The flag `--remove` is invalid; the correct flag is `--rm`.

podman run --rm -d -p 8080:80 nginx

Why it fails: Incorrect in this single-answer question. While the command is identical to B, it is not accepted as a second correct answer.

[ -f /path/to/file ]

Why it fails: -f checks if it's a regular file, not necessarily readable.

[ -x /path/to/file ]

Why it fails: -x checks if file is executable.

[ -s /path/to/file ]

Why it fails: -s checks if file is non-empty.

replicas

Why it fails: The replicas field is optional within the spec of a Deployment. It defaults to 1 if not specified, so it is not required.

spec

Why it fails: The spec field is required in a Deployment manifest to define the desired state, including the pod template and other settings.

if test -f $file || test -r $file; then

Why it fails: || is logical OR, so it checks if either condition is true.

if [ -f $file -a -r $file ]; then

Why it fails: While -a works in single brackets, it is deprecated and not recommended; the modern approach uses &&.

if [ -f $file -o -r $file ]; then

Why it fails: -o is logical OR, not AND.

CMD export

Why it fails: CMD provides defaults for the command, not for environment variables.

ARG

Why it fails: ARG defines build-time variables, not runtime environment variables.

RUN export

Why it fails: RUN export would set variables only during build, and they are not persisted in the final image.

kubectl get replicasets

Why it fails: This would show ReplicaSets, but not directly the desired number of replicas for the deployment.

kubectl get pods | wc -l

Why it fails: This shows the number of pod lines, but includes the header; also not specific to the deployment.

kubectl describe deployment mydeployment

Why it fails: This shows details including replicas, but it's more verbose than needed.

${GREETING:+World} when GREETING=Hello

Why it fails: This would output 'World' because GREETING is set.

${GREETING:-World} when GREETING=Hello

Why it fails: This would output 'Hello' because GREETING is set.

${GREETING:=World} when GREETING is unset

Why it fails: This would set GREETING to 'World' and output 'World', not 'Hello World'.

Using positional parameters $1, $2 directly

Why it fails: This does not handle flags; it assumes arguments are in order.

Using a here-document

Why it fails: A here-document is for input redirection, not option parsing.

Using the shift command only

Why it fails: shift alone is not sufficient for option parsing.

volumes

Why it fails: Volumes are for data persistence, not startup order.

links

Why it fails: links is deprecated and does not control startup order.

environment

Why it fails: Environment variables do not affect startup order.

ENTRYPOINT python app.py

Why it fails: ENTRYPOINT is also possible but typically used for the main command; CMD is more appropriate for specifying arguments or a simple default command.

RUN python app.py

Why it fails: RUN executes commands during image build, not at container start.

STARTUP python app.py

Why it fails: STARTUP is not a valid Dockerfile instruction.

while read f; do wc -l "$f"; done < /var/log/*.log

Why it fails: Redirecting the glob into the loop feeds file contents as input lines, so wc -l receives each line of text as a filename rather than the .log paths. It is tempting because while read is the right construct for processing a list of filenames supplied via a pipe or here-string.

for ((i=0; i<${#files[@]}; i++)); do wc -l "${files[$i]}"; done

Why it fails: The array files is never populated, so ${#files[@]} is zero and the loop body never executes. It is tempting because a C-style indexed loop is correct when an array has already been built, for example with files=(/var/log/*.log), giving explicit control over each element.

until [ -z "$f" ]; do wc -l "$f"; shift; done

Why it fails: An until loop tests a condition before each iteration and expects the variable to be set elsewhere; here $f is never assigned, so the loop body never runs. It is tempting because until suits polling until a state changes, such as waiting for a file to appear, not iterating a known file list.

- name: Ensure Apache is running systemd: name: httpd state: started enabled: yes

Why it fails: The systemd module is used for systemd systems, but the service module is more generic and recommended for CompTIA Linux+. However, systemd is also correct; but the question expects the service module as the standard Ansible module.

- name: Ensure Apache is running shell: systemctl start httpd && systemctl enable httpd

Why it fails: Using shell module is not idempotent and discouraged when a module exists.

- name: Ensure Apache is running command: systemctl enable --now httpd

Why it fails: Using command module is not idempotent and not best practice; Ansible modules should be used.

docker run -v /data-vol:/app/data myapp

Why it fails: Incorrect. The leading slash in `/data-vol` specifies a bind mount from the host, not a named volume, so it does not create a Docker volume.

docker volume create data-vol && docker run -v data-vol:/app/data myapp

Why it fails: Incorrect. This uses two separate commands (`docker volume create` and `docker run`), not a single command as implied by the question.

docker network create my-net

Why it fails: This command creates a network with the default driver, which is bridge, so it would also create a bridge network. However, the question expects the explicit use of -d bridge to specify the driver, making this option less precise and not the best answer.

docker create network -d bridge my-net

Why it fails: The syntax 'docker create network' is incorrect. The correct command is 'docker network create'.

docker network create --driver=overlay my-net

Why it fails: This command creates an overlay network, not a bridge network. Overlay is used for multi-host networking.

for user in $users; do echo "Welcome, $user"; done

Why it fails: $users expands only to the first element of the array.

for user in "${users[*]}"; do echo "Welcome, $user"; done

Why it fails: ${users[*]} expands to a single string with all elements joined by IFS, so the loop runs only once.

while read user; do echo "Welcome, $user"; done < <(printf '%s\n' "${users[@]}")

Why it fails: This is unnecessarily complex and not a simple loop for array iteration; it uses process substitution.

for (i=0; i<${#fruits[@]}; i++); do ... done

Why it fails: This syntax is for C-style loops, which works but is not the most straightforward for simple iteration.

for fruit in ${fruits[*]}; do ... done

Why it fails: Without quotes, elements with spaces may be split; also * expands to all elements but with IFS splitting.

for fruit in $fruits; do ... done

Why it fails: $fruits expands to only the first element.

set -v

Why it fails: set -v prints input lines as they are read, not as executed.

set -e

Why it fails: set -e exits on error, does not show commands.

set -o xtrace

Why it fails: This is equivalent to set -x but not the standard way.