RUN (BACKGROUND|REPEATABLE) [command ...]
The RUN instruction runs the given script, and fails the entire Layerfile if
the given command fails.
For example, you might use RUN echo "the directory is $(pwd)" to print your
current directory.
Examples
RUN echo helloprints “hello” to the terminalRUN BACKGROUND python3 -m http.serverrunpython3 -m http.serverpersistently in the background.RUN REPEATABLE docker build -t hellois a performance optimization, see tuning performance