Automation, Orchestration, and Scripting practice questions

kubectl describe pod

Why wrong: Shows pod details but not service endpoints.

kubectl get pods -o wide

Why wrong: Shows pod IPs but not service association.

kubectl get svc

Why wrong: Shows service details but not endpoints.

In a host_vars directory [wrong]

Why wrong: Variables in a host_vars directory apply to a specific host, which can be in a group, making it a valid way to define variables for hosts in different groups.

In the playbook itself using vars_files

Why wrong: vars_files in a playbook includes external variable files, but those variables apply at the play or task level, not specifically to a group of hosts.

In the roles directory

Why wrong: Roles directory contains role-specific variables, not group-specific variables.

":ab"

Why wrong: Incorrect because ':ab' silences error messages but does not require an argument for -b (no colon after b).

"ab"

Why wrong: Incorrect because 'ab' means both -a and -b take no argument.

"a:b"

Why wrong: Incorrect because 'a:b' means -a requires an argument and -b does not.

set -x

Why wrong: This enables debug tracing, not exit on error.

set -u

Why wrong: This treats unset variables as an error, but does not exit on command failure.

set -o pipefail

Why wrong: This only affects pipelines; it does not cause exit on all errors.

ADD config.txt /app/ and WORKDIR 8080

Why wrong: WORKDIR sets the working directory, not port exposure.

ADD config.txt /app/ and RUN expose 8080

Why wrong: RUN is not used to expose ports; EXPOSE is the correct instruction.

COPY config.txt /app/ and CMD 8080

Why wrong: CMD defines the default command, not port exposure.

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

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

systemd

Why wrong: The systemd module is more specific to systemd services, but service is the general module.

command

Why wrong: The command module runs arbitrary commands but is not idempotent for service management.

shell

Why wrong: Similar to command, but runs via shell; not idempotent.

docker start -i webapp

Why wrong: This starts a stopped container interactively, not exec into a running one.

docker run -it webapp bash

Why wrong: This creates a new container, not exec into an existing one.

docker attach webapp

Why wrong: Attach attaches to the container's main process, not start a new shell.

getopt

Why wrong: getopt is an external command that can handle long options but is not a built-in and differs in behavior.

case

Why wrong: case can be used to implement option parsing manually, but getopts is the standard tool.

shift

Why wrong: shift is used to shift positional parameters, not parse options.

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

Why wrong: 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 wrong: 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 wrong: `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.

Both allow variable expansion, but double quotes also allow globbing.

Why wrong: Single quotes do not allow expansion.

Single quotes allow variable expansion, double quotes do not.

Why wrong: It's the opposite.

There is no difference; they are interchangeable.

Why wrong: They have different behaviors.

docker create -t myapp:v1 .

Why wrong: create creates a container, not an image.

docker commit myapp:v1 .

Why wrong: commit creates an image from a container, not from a Dockerfile.

docker image create myapp:v1 .

Why wrong: There is no docker image create command; use build.

echo ${myvar#?????}

Why wrong: This removes the shortest prefix matching pattern; not substring extraction.

echo ${myvar:0-5}

Why wrong: This returns from 5th character from end to end.

echo ${myvar:5}

Why wrong: This returns from position 5 to end.

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

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

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

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

[ -x /path/to/file ]

Why wrong: -x checks if file is executable.

[ -s /path/to/file ]

Why wrong: -s checks if file is non-empty.

replicas

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

copy

Why wrong: The copy module copies files, does not manage packages.

service

Why wrong: The service module manages services, not packages.

template

Why wrong: The template module manages configuration files, not packages.

It sets the script to run in the background.

Why wrong: Running in the background is done with &, not the shebang.

It enables debugging mode.

Why wrong: Debugging is enabled with set -x.

It defines a variable for the script.

Why wrong: Variables are defined with VAR=value.

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

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

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

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

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

Why wrong: -o is logical OR, not AND.

set -u

Why wrong: set -u treats unset variables as an error but does not exit on command failure.

trap 'exit 1' ERR

Why wrong: This traps errors but does not automatically exit on every command failure; it requires explicit handling.

set -o pipefail

Why wrong: This causes a pipeline to fail if any command fails, but does not exit the script automatically unless combined with set -e.