You can get around the ash lack of COMMAND_PROMPT with PS1 and a runtime evaluated expression. $ docker run -it busybox sh -i # PS1="\$(date) " Sat Jul

You can get around the ash lack of COMMAND_PROMPT with PS1 and a runtime evaluated expression. $ docker run -it busybox sh -i # PS1="\$(date) " Sat Jul 5 09:21:53 UTC 2025 # waits a few and press <enter> Sat Jul 5 09:21:56 UTC 2025 # again Sat Jul 5 09:21:58 UTC 2025