What this snippet does
Any runtime argument replaces CMD wholesale, so the default only appears when none is given.
Expected output
default message
Why practise typing this
Typing cmd & entrypoint code builds muscle memory for the symbols and indentation Docker uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More Docker practice
- Exec form vs shell formCMD & ENTRYPOINT · intermediate
- Shell form swallows signalsCMD & ENTRYPOINT · intermediate
- Overriding CMD at run timeCMD & ENTRYPOINT · beginner
- Overriding ENTRYPOINTCMD & ENTRYPOINT · intermediate
- Entrypoint wrapper with execCMD & ENTRYPOINT · advanced
- Forgetting exec in the wrapperCMD & ENTRYPOINT · advanced