What does the WORKDIR instruction do in a Dockerfile?

What does the WORKDIR instruction do in a Dockerfile?

• A. Sets the working directory for subsequent instructions but does not create directories
• B. Sets the entrypoint
• C. Sets the working directory for subsequent instructions and creates a directory if required
• D. Exposes a port

Answer: (C)

WORKDIR defines the directory that becomes the current working directory for any following instructions in the Dockerfile. If that directory doesn’t exist yet, Docker will create it (including any needed parent directories) so later steps like RUN, COPY, ADD, CMD, or ENTRYPOINT operate from that location. For example, setting WORKDIR /app means subsequent commands run with /app as the base, and a COPY would place files into /app by default. This can be chained to move into subdirectories, with each new path created if missing. The other options refer to unrelated behaviors: one suggests no directory creation, another describes entrypoint, and the last describes port exposure. The described behavior—setting and ensuring the directory exists for subsequent instructions—is the correct understanding of WORKDIR.

WORKDIR defines the directory that becomes the current working directory for any following instructions in the Dockerfile. If that directory doesn’t exist yet, Docker will create it (including any needed parent directories) so later steps like RUN, COPY, ADD, CMD, or ENTRYPOINT operate from that location. For example, setting WORKDIR /app means subsequent commands run with /app as the base, and a COPY would place files into /app by default. This can be chained to move into subdirectories, with each new path created if missing. The other options refer to unrelated behaviors: one suggests no directory creation, another describes entrypoint, and the last describes port exposure. The described behavior—setting and ensuring the directory exists for subsequent instructions—is the correct understanding of WORKDIR.