Learning term
Restart policy — Docker fundamentals
Restart policy controls a defined transition in the container lifecycle. This card shows its role in “Docker fundamentals” and a safe diagnostic path.
Orientation
Restart policy controls a defined transition in the container lifecycle. At this level, separate purpose, input, and visible result. Place Restart policy within Docker fundamentals before changing settings or files.
Practical use
Check the exit code and stop timeout when the expected state transition does not complete. 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
Restart policy controls a defined transition in the container lifecycle. Technically, Restart policy 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 exit code and stop timeout when the expected state transition does not complete. 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 exit code and stop timeout when the expected state transition does not complete. 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 Restart policy — 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?