XK0-006 Automation, Orchestration, and Scripting Practice Test 6 — 15 Questions

Question 1

A DevOps engineer needs to run a Docker container in the background with port mapping from host port 8080 to container port 80, and name the container 'webapp'. Which command accomplishes this?

Accepted Answer

docker run -d -p 8080:80 --name webapp nginx. `docker run` is the command that creates AND starts a container in one step, and the `-d` flag detaches it to run in the background. The `-p 8080:80` flag maps host port 8080 to container port 80, and `--name webapp` assigns the container name. This is the canonical single-command way to launch a named, port-mapped, background container from the nginx image.

Answer

docker start -d -p 8080:80 --name webapp nginx

Answer

docker create -d -p 8080:80 --name webapp nginx

Answer

docker compose up -d -p 8080:80 --name webapp nginx

Question 2

A Linux administrator is writing a bash script that accepts command-line options: -a for all, -f for file, and -o for output. Which of the following correctly uses getopts to parse these options?

Accepted Answer

while getopts "afo" opt; do case $opt in a) ...;; f) ...;; o) ...;; esac; done. getopts uses a string of option characters; a colon after an option indicates it requires an argument. The correct usage is 'a:f:o' where a and f require arguments, but the stem doesn't specify arguments. Assuming -a and -f don't require arguments, the string should be 'afo'.

Answer

while getopts "-a -f -o" opt; do ... done

Answer

while getopts "a:f:o" opt; do case $opt in a) ...;; f) ...;; o) ...;; esac; done

Answer

getopts "afo" opt; case $opt in a) ...;; f) ...;; o) ...;; esac

Question 3

In a Kubernetes cluster, a developer needs to create a Deployment that runs three replicas of a container image 'myapp:1.0' and exposes port 8080. Which YAML snippet correctly defines this Deployment?

Accepted Answer

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: myapp:1.0
        ports:
        - containerPort: 8080. A Deployment YAML must have apiVersion, kind, metadata, spec with replicas and template containing container spec with image and ports.

Answer

apiVersion: v1
kind: Pod
metadata:
  name: myapp
spec:
  replicas: 3
  containers:
  - name: myapp
    image: myapp:1.0
    ports:
    - containerPort: 8080

Answer

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  selector:
    app: myapp
  template:
    containers:
    - name: myapp
      image: myapp:1.0
      ports:
      - containerPort: 8080

Answer

apiVersion: v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  template:
    spec:
      containers:
      - name: myapp
        image: myapp:1.0
        ports:
        - containerPort: 8080

Question 4

A user wants to execute a command inside a running Docker container named 'db'. Which command should be used?

Accepted Answer

docker exec -it db bash. 'docker exec -it db bash' runs a new interactive process (bash) inside the already-running container named 'db', attaching a TTY and keeping stdin open. This is the standard way to get a shell or run a one-off command in a live container without disturbing its main process. It does not restart or replace the container's entrypoint.

Answer

docker attach db

Answer

docker start -i db

Answer

docker run -it db bash

Question 5

A bash script needs to test whether a string variable $NAME is non-empty and equals 'admin'. Which of the following conditionals is correct?

Accepted Answer

if [[ -n $NAME && $NAME == 'admin' ]]; then. In bash, [[ -n $NAME ]] tests if the string is non-empty, and == compares strings. Using double brackets is safer for string comparison.

Answer

if [[ $NAME -ne '' && $NAME -eq 'admin' ]]; then

Answer

if [ $NAME != '' ] && [ $NAME == 'admin' ]; then

Answer

if [ ! -z $NAME -a $NAME = 'admin' ]; then

Question 6

A DevOps engineer is creating a Dockerfile for a Node.js application. Which THREE of the following instructions are valid and commonly used in a Dockerfile? (Choose THREE.)

Accepted Answer

COPY . /app. Option B, COPY . /app, is correct because COPY is a valid Dockerfile instruction that copies files from the build context into the image filesystem, here placing the application source into /app. Option C, RUN npm install, is correct because RUN executes commands during the image build, and npm install is the standard way to install Node.js dependencies inside the image. Option E, FROM node:14, is correct because FROM is the required first instruction in a Dockerfile that sets the base image, and node:14 is a valid Node.js base image tag. Option A, EXECUTE node app.js, is not a Dockerfile instruction; the correct instruction for starting the container process is CMD or ENTRYPOINT. Option D, INSTALL package.json, is also not a Dockerfile instruction; dependency installation is done with RUN, and package.json is typically copied with COPY.

Answer

EXECUTE node app.js

Answer

INSTALL package.json

Question 7

An administrator is troubleshooting a Pod in a Kubernetes cluster that is not starting. Which TWO kubectl commands are most useful for diagnosing the issue? (Choose TWO.)

Accepted Answer

kubectl logs <pod-name>. kubectl describe pod provides detailed event and status information, and kubectl logs retrieves container logs.

Answer

kubectl get nodes

Answer

kubectl apply -f pod.yaml

Answer

kubectl delete pod <pod-name>

Question 8

A Linux administrator wants to ensure a Bash script exits immediately if any command fails. Which directive should be included at the beginning of the script?

Accepted Answer

set -e. The `set -e` directive (equivalent to `set -o errexit`) causes the shell to exit immediately when any command returns a non-zero exit status, unless that command is part of a condition (if/while/until) or followed by `||`. This is the standard way to make a Bash script fail fast on the first error. Placing it near the top of the script ensures subsequent commands are not executed after a failure.

Answer

set -o pipefail

Answer

set -u

Answer

set -x

Question 9

A developer is writing a Bash script that needs to parse command-line options with arguments, such as -f filename and -v. Which built-in command should be used to handle these options?

Accepted Answer

getopts. getopts is the standard Bash built-in for parsing short options with or without arguments.

Answer

getopt

Answer

case

Answer

shift

Question 10

A Linux administrator needs to run a Docker container in detached mode with port mapping from host port 8080 to container port 80, and mount a host directory /data to /app/data inside the container. Which command achieves this?

Accepted Answer

docker run -d -p 8080:80 -v /data:/app/data --name webapp nginx. It uses `docker run -d` to start the container in detached mode (background), `-p 8080:80` to map host port 8080 to container port 80, and `-v /data:/app/data` to bind-mount the host directory `/data` to the container path `/app/data`. The `--name webapp` assigns a friendly name, and `nginx` specifies the image. This combination exactly matches all requirements.

Answer

docker run -it -p 8080:80 -v /data:/app/data --name webapp nginx

Answer

docker run -d -P -v /data:/app/data --name webapp nginx

Answer

docker start -d -p 8080:80 -v /data:/app/data webapp

Question 11

An administrator is writing a Dockerfile. They need to set a default command that can be overridden when running the container. Which instruction should be used?

Accepted Answer

CMD. CMD provides defaults that can be overridden by command-line arguments, while ENTRYPOINT cannot be easily overridden without --entrypoint.

Answer

RUN

Answer

ENTRYPOINT

Answer

EXPOSE

Question 12

In a Bash script, what is the correct way to check if a file named '/etc/passwd' exists and is a regular file?

Accepted Answer

if [ -f /etc/passwd ]. The `-f` test operator in Bash returns true only if the path exists AND is a regular file (not a directory, device, or symlink to a non-regular file). This exactly matches the requirement to check that /etc/passwd exists and is a regular file.

Answer

if [ -r /etc/passwd ]

Answer

if [ -e /etc/passwd ]

Answer

if [ -s /etc/passwd ]

Question 13

A system administrator needs to update a configuration file on multiple servers using Ansible. The playbook must ensure the line 'MaxAuthTries 3' is present in /etc/ssh/sshd_config. Which Ansible module is most appropriate?

Accepted Answer

lineinfile. The lineinfile module ensures a specific line is present in a file, ideal for configuration management.

Answer

template

Answer

shell

Answer

copy

Question 14

A container is running and a technician needs to execute an interactive shell inside it. The container was started with 'docker run -d --name myapp myimage'. Which command will achieve this?

Accepted Answer

docker exec -it myapp /bin/bash. 'docker exec -it myapp /bin/bash' attaches a new interactive TTY session to the already-running container named myapp and launches /bin/bash inside it. The -i flag keeps STDIN open and -t allocates a pseudo-TTY, which is required for an interactive shell. Because the container is already running, exec is the correct tool rather than run.

Answer

docker attach myapp

Answer

docker run -it --name myapp myimage /bin/bash

Answer

docker logs -f myapp

Question 15

In a Bash script, what is the purpose of the shebang '#!/bin/bash'?

Accepted Answer

It specifies the path to the Bash executable that should run the script.. The shebang tells the system which interpreter to use to execute the script.

Answer

It defines a variable for the Bash version.

Answer

It sets the script's permissions to executable.

Answer

It enables debug mode for the script.