Refer to the exhibit. Which line of code completes the Dockerfile?

Question

Exhibit

Options

• ARUN chmod 777 /usr/bin/sample.py
• BRUN chown root:root /usr/bin/sample.py
• CWORKDIR /usr/bin
• DUSER root

• A
  75% (18)
• B
  8% (2)
• C
  13% (3)
• D
  4% (1)

Explanation

Option A is correct because placing a Python script in /usr/bin/sample.py is useless unless the file has execute permissions - chmod 777 grants read, write, and execute permissions to all users, making the script runnable as a command inside the container.

Why the distractors are wrong:

• B (chown root:root) - Files copied into a Docker image are already owned by root by default; changing ownership doesn't grant execute permission, so the script still couldn't run.
• C (WORKDIR /usr/bin) - This only sets the working directory for subsequent instructions; it doesn't affect file permissions or make sample.py executable.
• D (USER root) - Switching to the root user changes who runs future commands, not whether the file itself is executable; without execute bits set, even root can't run it as a script directly.

Memory tip: In Dockerfiles, anytime you COPY a script into a bin directory (a location meant for executables), your next thought should be "can this actually execute?" - chmod +x (or 777) is the answer. If it's not executable, it's just a text file sitting in a bin folder.

No community discussion yet for this question.