EX188 Container Image Building Practice Test 3 — 15 Questions

Question 1

You need to ensure that a container image built with Podman includes reproducible timestamps for files to improve security and supply chain verification. Which flag or environment variable controls this?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

SOURCE_DATE_EPOCH. Setting SOURCE_DATE_EPOCH environment variable ensures reproducible builds by normalizing file timestamps.

Answer

PODMAN_REPRODUCIBLE_BUILD=true

Answer

TIMESTAMP=0 in the Containerfile ENV

Answer

--reproducible flag in podman build

Question 2

Which TWO Containerfile instructions are used to bring files or data from outside the container into the build context or image? (Choose two.)

Accepted Answer

COPY. COPY and ADD are the two instructions designed to move external files into the image filesystem.

Answer

GET

Answer

FETCH

Answer

IMPORT

Question 3

Which TWO commands can be used with Podman to build a container image from a Containerfile? (Choose two.)

Accepted Answer

podman image build. podman build and podman image build are both valid commands for building images.

Answer

podman container build

Answer

podman make image

Answer

podman create build

Question 4

Which TWO options are valid flags for the 'podman build' command to specify build arguments and tags? (Choose two.)

Accepted Answer

--build-arg. --build-arg and --tag (-t) are standard options for podman build.

Answer

--volume

Answer

--publish

Answer

--env-file

Question 5

Which TWO statements are true regarding the EXPOSE instruction in a Containerfile? (Choose two.)

Accepted Answer

It informs Podman that the container listens on the specified network ports at runtime.. EXPOSE serves as documentation and assists orchestration tools in understanding which ports to publish when using flags like -P.

Answer

It replaces the need to define environment variables for port configuration.

Answer

It enforces strict firewall rules inside the container network namespace, blocking unexposed ports.

Answer

It automatically publishes all exposed ports to random host ports without needing the -p or -P flag.

Question 6

Which TWO instructions are used to define variables or set environment values within a Containerfile? (Choose two.)

Accepted Answer

ARG. ARG and ENV are used for defining build arguments and environment variables respectively.

Answer

DEFINE

Answer

VAR

Answer

SET

Question 7

Which THREE practices should be followed to optimize container image size and build caching when writing Containerfiles? (Choose three.)

Accepted Answer

Order Containerfile instructions from least frequently changing to most frequently changing to maximize cache hits.. Caching and layer minimization depend on instruction order, cleanup in the same layer, and avoiding unnecessary tool installation.

Answer

Avoid using .containerignore files so that all host files are always cached by Podman.

Answer

Install all debugging tools and heavy development SDKs in the final production stage.

Question 8

Which THREE mechanisms are valid ways to pass build arguments into a Containerfile during a 'podman build' invocation? (Choose three.)

Accepted Answer

Placing default values directly in the Containerfile using 'ARG KEY=DEFAULT_VALUE'.. Build arguments can be passed via command line flags or environment files during build.

Answer

Using the '--build-arg-file' flag to read variables from a file.

Answer

Using the '--env-file' flag during 'podman build' to populate ARG variables.

Question 9

Which THREE statements are correct regarding the behavior and usage of the WORKDIR instruction? (Choose three.)

Accepted Answer

It can be used multiple times in a single Containerfile to change directories relative to previous WORKDIR paths or absolute paths.. WORKDIR sets the path, creates the directory if missing, and affects subsequent instructions.

Answer

It permanently modifies the host machine's current working directory where 'podman build' was executed.

Answer

It replaces the need to specify absolute paths in COPY and ADD instructions.

Question 10

Which THREE features or characteristics distinguish the ADD instruction from the COPY instruction in a Containerfile? (Choose three.)

Accepted Answer

ADD can automatically extract local compressed tar archive files into the destination directory.. ADD supports remote URLs, auto-extraction of tarballs, and local sources, whereas COPY only supports local sources.

Answer

ADD requires the source file to be located within a git repository, unlike COPY.

Answer

COPY supports remote URLs natively just like ADD.

Question 11

Which THREE statements are true concerning how Podman builds container images and utilizes the build context? (Choose three.)

Accepted Answer

A file named '.containerignore' (or '.dockerignore') can be used to exclude files from being sent to the build context.. The build context is sent to the builder, .containerignore excludes files, and standard stdin can be used.

Answer

Podman cannot accept a Containerfile via standard input (stdin); it must always read from a file on disk.

Answer

Files outside the build context directory can be freely copied into the image using standard COPY instructions without extra flags.

Question 12

Which THREE directives or practices are associated with implementing secure container builds and adhering to least-privilege principles? (Choose three.)

Accepted Answer

Using minimal, trusted base images to reduce the total software footprint and vulnerability surface.. Secure builds involve using non-root users, secure secret mounting, and trusted base images.

Answer

Hardcoding database passwords directly into ENV instructions so the application can read them easily.

Answer

Running all RUN instructions with '--privileged' inside the Containerfile.

Question 13

Which THREE behaviors occur when utilizing multi-stage builds in a Containerfile? (Choose three.)

Accepted Answer

You can include multiple 'FROM' instructions in a single Containerfile, where each 'FROM' starts a new stage of the build.. Multi-stage builds allow multiple FROM lines, naming stages, and selective copying between them.

Answer

All intermediate stages are automatically tagged and pushed to the local registry when the build completes.

Answer

Artifacts from earlier stages are automatically merged into the final image layers unless explicitly deleted.

Question 14

Which THREE conditions or practices can cause layer cache invalidation during a 'podman build' operation? (Choose three.)

Accepted Answer

Modifying the content or modification timestamp (mtime) of a file referenced by a COPY instruction.. Cache invalidation happens when instructions change, files change (checksum/mtime), or ARG values change.

Answer

Adding a comment line '#' at the very top of the Containerfile before the first FROM instruction.

Answer

Running 'podman build' on a different physical workstation while using the exact same build context and Containerfile.

Question 15

Which THREE statements accurately describe the differences between shell form and exec form for CMD and ENTRYPOINT instructions? (Choose three.)

Accepted Answer

Exec form ensures that Unix signals (such as SIGTERM) sent by Podman are received directly by the application process as PID 1.. Exec form uses JSON array syntax, avoids running a shell, and correctly passes signals as PID 1.

Answer

Shell form is mandatory when using multi-stage builds.

Answer

Exec form allows shell variable expansion (like $VAR) directly without needing explicit shell invocation.