Learning term
Build context — Docker fundamentals
Build context is the file set available to the Docker builder for COPY and ADD. This card shows its role in “Docker fundamentals” and a safe diagnostic path.
Orientation
Build context is the file set available to the Docker builder for COPY and ADD. At this level, separate purpose, input, and visible result. Place Build context within Docker fundamentals before changing settings or files.
Practical use
Check the context path and .dockerignore when COPY cannot find an existing file. Start in a sandbox with neutral examples. Record the expected state, make one controlled change, and compare status output, application behavior, and logs.
Technical understanding
Build context is the file set available to the Docker builder for COPY and ADD. Technically, Build context connects through interfaces, configuration, state, or dependencies. Trace data from input to output and check versions, permissions, networking, storage, and resources separately.
Operations and debugging
Check the context path and .dockerignore when COPY cannot find an existing file. In production-like operations, use measurable signals, least privilege, reproducible configuration, and a documented rollback. Preserve evidence, isolate the cause, and verify the correction with the same test.
Exercise
Try it safely
Check the context path and .dockerignore when COPY cannot find an existing file. Open an isolated test environment and run “docker version && docker info”. Write down the expected output first, do not alter production data, and record one safe next diagnostic step.
docker version && docker infoQuick check
Can you explain the purpose, observable state, and most common failure source of Build context — Docker fundamentals in one sentence each? Which evidence would you preserve before changing anything, and which repeated test would prove that the correction actually worked?